Should I be doing more BMF intake testing?

[acannell]

Have I underestimated how much people want data on the BMF Intake?

I've kind of ignored doing any testing on it and just focused on machining and welding it.

Besides moparzrule I think I'm the only person who has it installed in a working vehicle.

Are there any tests people would like to see?

I have a pretty small turbo (the "super 46" hybrid from FWP), stock cam, long primary tubular header, huge intercooler, H20 injection, and stock swirl head.

I have a flashable ECU so I could put tunes into there.

Is my build to weird to mean much?

[tryingbe]

Unless you're going to make another bunch of 30, I don't see the point of testing. They are already sold out!

[acannell]

Unless you're going to make another bunch of 30, I don't see the point of testing. They are already sold out!

oh I'm definitely making more :)

[2.216VTurbo]

How about you find a flowbench place, flow a 2 piece stocker, flow your BMF, then sell lots of them based on the big numbers.:eyebrows:

[acannell]

How about you find a flowbench place, flow a 2 piece stocker, flow your BMF, then sell lots of them based on the big numbers.:eyebrows:

Im guessing one of the existing purchasers like Pope will probably put it on a flow bench because they have those tools already..and probably a 2 piece. Both of which I dont have.

I mean more like in-car stuff. I could probably do a back to back with a stock 1 piece intake but it wouldnt mean much without a tune to match each intake I suppose...

[turismolover22]

I thibk regardless if you do any testing yourself or not, they will sell. Someone will install it, or bench it, and see big gains and it will speak volumes (no pun intended)

[Shadow]

There is really not much you will be able to do to "test" or "Prove" the intake on your platform. It is really designed for much more. The only thing you could really do is bolt it on and prove that you Can run it with minimal mods and still be drivable. (If that makes any sense) and you've already done that.

You Didn't build this Blind. Remember, it was built using the parameters from the Intake that is working on the Charger right now, coupled with parameters from what I know of Warren's and a few other intakes.

So it Should work as well or Better than the intake on the Charger and we Gained 30WHP (minimal) when switching from a Fully ported 2 piece @ 33lbs boost on the 57 trim turbo. And that was while still on the STOCK cam! lol

So I Think you Should be safe to let others do the testing and see what comes out of it ;)

[acannell]

There is really not much you will be able to do to "test" or "Prove" the intake on your platform. It is really designed for much more. The only thing you could really do is bolt it on and prove that you Can run it with minimal mods and still be drivable. (If that makes any sense) and you've already done that.

You Didn't build this Blind. Remember, it was built using the parameters from the Intake that is working on the Charger right now, coupled with parameters from what I know of Warren's and a few other intakes.

So it Should work as well or Better than the intake on the Charger and we Gained 30WHP (minimal) when switching from a Fully ported 2 piece @ 33lbs boost on the 57 trim turbo. And that was while still on the STOCK cam! lol

So I Think you Should be safe to let others do the testing and see what comes out of it ;)

Yeah this probably makes the most sense especially if so many people are going to be testing/tuning with it..my little turbo build wont even get noticed in the pile lol

[OmniLuvr]

i dont think youll need more testing but maybe more "tuning/tweeking" it, like what shadow did and put a little turn up on the runners to clear the turbo better? im planning on making the runners shorter, thats why im going for unwelded. i was even thinking of making it a "2 piece" design. being able to separate the runners from the plenum somehow, either plenum separates from runners like a 2 piece, or runners cut in 2 and held together with v-bands, 2 bolt flanges, or silicone tubing (im worried about the heat though). just an idea...

but either way, THANK YOU FOR WORKING WITH OUR COMMUNITY!

[acannell]

i dont think youll need more testing but maybe more "tuning/tweeking" it, like what shadow did and put a little turn up on the runners to clear the turbo better? im planning on making the runners shorter, thats why im going for unwelded. i was even thinking of making it a "2 piece" design. being able to separate the runners from the plenum somehow, either plenum separates from runners like a 2 piece, or runners cut in 2 and held together with v-bands, 2 bolt flanges, or silicone tubing (im worried about the heat though). just an idea...

but either way, THANK YOU FOR WORKING WITH OUR COMMUNITY!

The lack of bends is 100% intentional. AFAIK Shadow decided not to go with the bends, but maybe he'll change his mind. I've already gone over why there are straight runners and why I think bends should not be added in another thread so I wont go into it again except to say that adding bends is expensive and difficult and you get pretty much nothing for your time and money. That applies whether I was to change the design or whether someone attempts it on their own after-the-fact. I would have to raise the cost of the BMFI by about $125 to add bends. Someone who tries to do it themselves is looking at around $80 in tubing and probably a good 2 days of fabricating, and thats for someone at Shadow's skill level. And the results are what exactly? Eliminating the need to do minor grinding for certain headers? It would be much easier to just grind the headers instead of trying to add bends to the BMFI. Knownenemy and Moparzrule have both shown what is required to fit certain large headers and its very minimal grinding anyone can do.

I've played around with the idea of a BMFI that can be taken apart at the runners but I can't see a real reason for it. If I were to do it it would be with orings and proper bore/piston seals. But again I'm not sure what there is to be gained by doing it. It should be noted that with a G-body, 0.63 housing, and stock exh. mani, the BMFI can be removed and installed in-car. without removing the head or the exhaust mani.

And you are welcome!! Thank you for your support!!

[5DIGITS]

Have I underestimated how much people want data on the BMF Intake?
I've kind of ignored doing any testing on it and just focused on machining and welding it.
Besides moparzrule I think I'm the only person who has it installed in a working vehicle.
Are there any tests people would like to see?
I have a pretty small turbo (the "super 46" hybrid from FWP), stock cam, long primary tubular header, huge intercooler, H20 injection, and stock swirl head.
I have a flashable ECU so I could put tunes into there.
Is my build to weird to mean much?

If it helps, there's a few tests that can be done to qualify the impact of a new intake design.
When changing the plenum size and reducing runner length, it would be expected that the intake tuning will change.
Understanding how this has influenced the tuning peaks and the roll it plays on the torque and HP curves are vital pieces of information and typically not realized on a flow bench.
Therefore, running tests between a ported two-piece and the new unit will identify the areas of gain and loss due to these changes in intake tuning pulses.
Although the two-piece was a superior part vs the one-piece, both will begin to choke when higher boost levels are requested, unless the problem areas are addressed.
With this, testing should consider boost level conditions throughout a range that will expose where each thrives and where the limitations lie.
Because the above is ideal for exposing shifts in the torque/HP curves across varying operating ranges, it also opens the door to best optimize cam timing to compliment the new direction.

Hope this helps

[zin]

As usual 5digits dropping some knowledge!

I'm pretty much in agreement with what folks have already said, this is a big step in the right direction, imperfect for everyone though it may be.

My suggestion would be to not do more testing, it is what it is (for this batch anyway), rather I'd suggest collecting info on your customer's combinations, then adjust the design to better fit them.

Mike

[Shadow]

The lack of bends is 100% intentional. AFAIK Shadow decided not to go with the bends, but maybe he'll change his mind. I've already gone over why there are straight runners and why I think bends should not be added in another thread so I wont go into it again except to say that adding bends is expensive and difficult and you get pretty much nothing for your time and money. That applies whether I was to change the design or whether someone attempts it on their own after-the-fact. I would have to raise the cost of the BMFI by about $125 to add bends. Someone who tries to do it themselves is looking at around $80 in tubing and probably a good 2 days of fabricating, and thats for someone at Shadow's skill level. And the results are what exactly? Eliminating the need to do minor grinding for certain headers? It would be much easier to just grind the headers instead of trying to add bends to the BMFI. Knownenemy and Moparzrule have both shown what is required to fit certain large headers and its very minimal grinding anyone can do.

The reasons for adding the bent runners were tri-fold. The #1 reason was to Add some length, as the runners are a little on the short side vs cross section and it will give a little better drivability. IMO

The rest are just added bonuses. The Zero clearance issues for all applications and getting the TB neck centered in the plenum so that a Hemisphere can be used.

I would have Zero problem paying 125.00 more for this to happen on a welded version in the future! :nod:

[acannell]

The reasons for adding the bent runners were tri-fold. The #1 reason was to Add some length, as the runners are a little on the short side vs cross section and it will give a little better drivability. IMO

The rest are just added bonuses. The Zero clearance issues for all applications and getting the TB neck centered in the plenum so that a Hemisphere can be used.

I would have Zero problem paying 125.00 more for this to happen on a welded version in the future! :nod:

I'm definitely interested to see what you've come up with! I'm just looking at the BMFI from my perspective and goals of keep the cost down as much as possible and getting people 99% there as far as fitment with only very basic fab skills needed to finish the job if any. But this intake is meant to be modified and customized as need be for sure.

[5DIGITS]

I'm definitely interested to see what you've come up with!
I'm just looking at the BMFI from my perspective and goals of keep the cost down as much as possible and getting people 99% there as far as fitment with only very basic fab skills needed to finish the job if any.
But this intake is meant to be modified and customized as need be for sure.

I've received several questions regarding knock sensor placement on the intake along with a few photos of what some have done.
As a consideration, implementing a provision that supports having the knock sensor on the mounting boss within cylinders 2 or 3 would serve well.
One of the photos had a thin welded bridge between the bosses but this raises concerns of signal accuracy and added resonant back ground noise.
This would be further aggravated, if the material is too thin and not welded at all points of contact with the intake mounting/injector boss (top, bottom and sides)
If this is to be completed by the 'user', a welded boss (around the entire diameter) consisting of 1.000" - 1.250" round aluminum bar stock is ideal while keeping it as short as possible.

[acannell]

I've received several questions regarding knock sensor placement on the intake along with a few photos of what some have done.
As a consideration, implementing a provision that supports having the knock sensor on the mounting boss within cylinders 2 or 3 would serve well.
One of the photos had a thin welded bridge between the bosses but this raises concerns of signal accuracy and added resonant back ground noise.
This would be further aggravated, if the material is too thin and not welded at all points of contact with the intake mounting/injector boss (top, bottom and sides)
If this is to be completed by the 'user', a welded boss (around the entire diameter) consisting of 1.000" - 1.250" round aluminum bar stock is ideal while keeping it as short as possible.


AFAIK moparzrule is the only person to have mounted a knock sensor with the BMFI, and he did the flange to flange welded on strip as you describe. I am not an advocate of this method because I would prefer things not be welded flange to flange for mechanical reasons, but I am being very conservative when it comes to that sort of thing, its probably okay mechanically. I am not sure about acoustically though, for the reasons you describe.

So, the solutions I am aware of for knock sensor mounting with the BMFI are:

1) moparzrule style with welded strip from #2 to #3 flange, drilled and tapped for sensor (requires welding and basic fab skills)

2) CNC machined knock sensor mount bolted to head ($$ to buy the mount from me, basic fab skills to modify your head to mount it, puts it a few mm from stock, very solid mounting)

3) Making #2 yourself. (basic fab skills, put it within mm of stock, very solid mounting)

4) Drilling and tapping the plenum for the knock sensor. (basic fab skills, puts it a few inches away from stock)

5) Grinding/filing a flat on #2 or #3 flange injector surface and drilling and tapping for knock sensor (basic fab skills. puts it ~1 inch from stock, very solid mounting, not centered audio-wise though)

6) ?

I am a fan of #2, #3, and possibly #5, all of which keep in the BMF spirit of easy, cheap, and extremely effective, since they avoid welding, require only basic fab skills, and provide a very solid mount very close to the stock position.

Here are some pics of the sensor mount I was considering offering as an upgrade:

http://i242.photobucket.com/albums/ff197/acannell/ksm1_zpsd673e0b3.jpg
http://i242.photobucket.com/albums/ff197/acannell/ksm2_zpse9ef70d2.jpg

http://i242.photobucket.com/albums/ff197/acannell/untitled_zps58a1c46d.jpg

[OmniLuvr]

I'm just looking at the BMFI from my perspective and goals of keep the cost down as much as possible and getting people 99% there as far as fitment with only very basic fab skills needed to finish the job if any

AND YOU HAVE DONE THAT!!! sorry for not being able to read through all the threads, ive gotten kind of lost in how many threads your intake has come up. but I do like the custom knock sensor mount

[BoostedDrummer]

Have I underestimated how much people want data on the BMF Intake?


http://i61.tinypic.com/107s0b8.jpg

[acannell]

http://i61.tinypic.com/107s0b8.jpg

hahahahaahahaah literally LOL thank you for that

[zin]

5Digits, what about finding a place on the block to mount the knock sensor to? Is the code used position sensitive, that is, would it misinterpret the signal if it isn't between 2 & 3 and higher up? If so, is there any way to change it to allow a block mounted knock sensor as it used on the newer engines?

Mike

[Shadow]

I'm definitely interested to see what you've come up with! I'm just looking at the BMFI from my perspective and goals of keep the cost down as much as possible and getting people 99% there as far as fitment with only very basic fab skills needed to finish the job if any. But this intake is meant to be modified and customized as need be for sure.

Keep in mind, this Doesn't change the Fact that you can continue to offer the VI version even "as is" while offering "More for More" ie. More Moola = More mods to Manifold ;)

Someone who is willing to spend the extra $'s gets the angled longer runner version, maybe even pays to have the knock sensor mount, ect ect. :nod:

[OmniLuvr]

and that's why I chose the unwelded version, id like to make mine a little more "modular" so I can change lengths of runners, and have easier access to the turbo if needed. but I am glad to hear the manifold can be removed while the turbo and exhaust are still installed!

[acannell]

and that's why I chose the unwelded version, id like to make mine a little more "modular" so I can change lengths of runners, and have easier access to the turbo if needed. but I am glad to hear the manifold can be removed while the turbo and exhaust are still installed!

to be clear im not sure if it can on anything but a stock exhaust manifold and smaller turbo on a G body..other setups may be different..I dont think anyone has tried it besides me

[turismolover22]

Just by design the intake looks to be removeable without other things such as the exhaust manifold being removed. Since you can get at all 8 bolts through the top and not the bottom, it opens up the possibility of pulling it in-car. But I dont have one in front of me, so I couldn't say for certain

[4 l-bodies]

Just by design the intake looks to be removeable without other things such as the exhaust manifold being removed. Since you can get at all 8 bolts through the top and not the bottom, it opens up the possibility of pulling it in-car. But I dont have one in front of me, so I couldn't say for certain
Then the real trick will be changing out the intake/exhaust gasket after removing the intake without removing the exhaust manifold (lol). We need that guy to repop those copper 8V intake/exhaust gaskets. I knew I should have bought one!
Todd

[OmniLuvr]

Since you can get at all 8 bolts through the top and not the bottom

awesome!


Then the real trick will be changing out the intake/exhaust gasket after removing the intake without removing the exhaust manifold

crap...

[Dr. Johny Dodge]

still though , it should make removeing everything from the back of the head much easier while the motor is still in the car

...back to awesome

[acannell]

Then the real trick will be changing out the intake/exhaust gasket after removing the intake without removing the exhaust manifold (lol). We need that guy to repop those copper 8V intake/exhaust gaskets. I knew I should have bought one!
Todd

I've done it probably 5 times without changing my manifold gasket..there is very little damage done to it in the short term. I think it might start "bonding" to stuff only after alot of miles and heat? YMMV

BTW the procedure to get the BMFI on and off in-car is merely possible, its not fun or easy. You have to have a tiny ratcheting wrench, ball-end allen wrenches that are about 6" long and may need to be cut to length, etc..etc...once you have your little collection of special tools to do it I'd say you are good to go. You have to get to the bolts from both the top and bottom for various parts of loosening them. The swingvalve/top of turbo makes those 2 bolts very tricky, you need to really get a good angle in there with the ball allen wrench.

OTOH maybe someone will figure out a better combo of tools to do it.

And again, this all applies only to the 0.63" housing, stock exhaust manifold, G-body, etc...I have no idea if its possible on anything else.

[5DIGITS]

AFAIK moparzrule is the only person to have mounted a knock sensor with the BMFI, and he did the flange to flange welded on strip as you describe. I am not an advocate of this method because I would prefer things not be welded flange to flange for mechanical reasons, but I am being very conservative when it comes to that sort of thing, its probably okay mechanically. I am not sure about acoustically though, for the reasons you describe.

So, the solutions I am aware of for knock sensor mounting with the BMFI are:

1) moparzrule style with welded strip from #2 to #3 flange, drilled and tapped for sensor (requires welding and basic fab skills)

2) CNC machined knock sensor mount bolted to head ($$ to buy the mount from me, basic fab skills to modify your head to mount it, puts it a few mm from stock, very solid mounting)

3) Making #2 yourself. (basic fab skills, put it within mm of stock, very solid mounting)

4) Drilling and tapping the plenum for the knock sensor. (basic fab skills, puts it a few inches away from stock)

5) Grinding/filing a flat on #2 or #3 flange injector surface and drilling and tapping for knock sensor (basic fab skills. puts it ~1 inch from stock, very solid mounting, not centered audio-wise though)

6) ?

I am a fan of #2, #3, and possibly #5, all of which keep in the BMF spirit of easy, cheap, and extremely effective, since they avoid welding, require only basic fab skills, and provide a very solid mount very close to the stock position.


Nice clear drawing !
With so many ways to accomplish the task, there are things to keep in mind no matter which path is taken.

Insure the injector bodies do not contact the intake at any locations to avoid injector noise transfer into the intake boss.
If the billet stock is used, insure that total surface contact from the head to the knock boss is obtained - corroded heads may be a problem
Do not allow the knock boss to contact the surrounding intake bosses to avoid resonant vibrations - consider reducing the width to insure clearances (see pic)


http://www.turbo-mopar.com/forums/attachment.php?attachmentid=52064&stc=1

[black86glhs]

Will be interesting to see if bolting it there, will see injector noise, even with good clearance between it and the intake flanges. I see a lot of noise causing issues, but that is just shooting from the hip on my part.

[acannell]

Will be interesting to see if bolting it there, will see injector noise, even with good clearance between it and the intake flanges. I see a lot of noise causing issues, but that is just shooting from the hip on my part.

I would imagine there would be less coupling than stock, because at least the sound has to go to the head before it gets back to the sensor, while stock, the injectors and the sensor are literally in the same piece of metal. But who knows....

[black86glhs]

Asa....I agree that the stock one is not in the best location either. Very likely I am wrong, just throwing it out there in case someone wants to give it more thought. I have always wondered if the front side of the head was a better place. That probably would have required reworking the head for a good place to put it. They weren't going to put in the $$$$ for that, IMO.

[acannell]

Asa....I agree that the stock one is not in the best location either. Very likely I am wrong, just throwing it out there in case someone wants to give it more thought. I have always wondered if the front side of the head was a better place. That probably would have required reworking the head for a good place to put it. They weren't going to put in the $$$$ for that, IMO.

just an update, I have actually machined a prototype of this

it could be installed on the front of the head I think, or anywhere you could drill and tap the holes for it

http://www.turbo-mopar.com/forums/showthread.php?76852-BMF-KSM-development!

http://i242.photobucket.com/albums/ff197/acannell/20141212_185056_zpshmmihurn.jpg

[knownenemy]

How about you find a flowbench place, flow a 2 piece stocker, flow your BMF, then sell lots of them based on the big numbers.:eyebrows:

I don't think you'd even have to waste time or money flowing the 2pc.
Just have the BMF flowed, and note the results.

I think the numbers would be so great that testing a 2pc. would be an obvious waste of time for BMF owners.

If you were considering it for folks who MAY buy a BMF, then you'd probably have to flow many different setups;
Stock 2pc, stock 1pc, ported 2pc, ported 1pc, and surely many more.
There's just too many different setups to try and "compare" to the BMF's flow numbers.

But having BMF flow results available would be great for folks to have their previous intake done,
and then compare to the flow #s of the BMF.

- As for the KSM idea; I think it's a fantastic one.
But on that same note, I'd like to get input on what people think of mounting it directly to the head,
in the same position your KSM mounts.
Sorry to hijack the thread, but I'd like to hear what others think about
drilling and tapping the KS threads directly into the head between #2 & #3 cyls.

Or in a bit more complicated way,
TIG an aluminum boss with the KS threads directly to the head,
and mount the KS in it.

[Reaper1]

Just as a note the Masi 16V engines have the knock sensor mounted on the front of the block where the one engine mount boss is that normally isn't used on the FWD blocks (it's only drilled and tapped in Dakota blocks and the Masi AFAIK). I am pretty sure it was determined that the knock code for the Masi and the 8V engines are the same.

[acannell]

I don't think you'd even have to waste time or money flowing the 2pc.
Just have the BMF flowed, and note the results.

I think the numbers would be so great that testing a 2pc. would be an obvious waste of time for BMF owners.

If you were considering it for folks who MAY buy a BMF, then you'd probably have to flow many different setups;
Stock 2pc, stock 1pc, ported 2pc, ported 1pc, and surely many more.
There's just too many different setups to try and "compare" to the BMF's flow numbers.

But having BMF flow results available would be great for folks to have their previous intake done,
and then compare to the flow #s of the BMF.

- As for the KSM idea; I think it's a fantastic one.
But on that same note, I'd like to get input on what people think of mounting it directly to the head,
in the same position your KSM mounts.
Sorry to hijack the thread, but I'd like to hear what others think about
drilling and tapping the KS threads directly into the head between #2 & #3 cyls.

Or in a bit more complicated way,
TIG an aluminum boss with the KS threads directly to the head,
and mount the KS in it.

Just to be clear, I'm all for whatever testing anyone thinks of as far as evaluating components.

However I am a little doubtful as to how well an intake manifold can be flow tested, since plenum volume plays such a big role (in theory) and that will not be reflected in a static flow test. In the same way that runner length causing pressure waves to help flow would not be detected in a static test.

So while I think a flow test can tell you something, its going to be missing some important information in that regard.

And in order for the test to be used for relative comparison I would say test the BMF versus whatever else on the same flow bench, otherwise things start getting apples to oranges with different flow benches dont they?

[Shadow]

Just as a note the Masi 16V engines have the knock sensor mounted on the front of the block where the one engine mount boss is that normally isn't used on the FWD blocks (it's only drilled and tapped in Dakota blocks and the Masi AFAIK). I am pretty sure it was determined that the knock code for the Masi and the 8V engines are the same.

Can you absolutely verify that the knock code is the same? This would be a nice simple solution for sure.

[1984rampage]

Just as a note the Masi 16V engines have the knock sensor mounted on the front of the block where the one engine mount boss is that normally isn't used on the FWD blocks (it's only drilled and tapped in Dakota blocks and the Masi AFAIK). I am pretty sure it was determined that the knock code for the Masi and the 8V engines are the same.

Pics of the engine mount boss / knock sensor mounting on the Masi motor ?

[iTurbo]

52697

Picture of the Masi 16v knock sensor mounted in the block. You can see the (broken) knock sensor mounted just right of the oil filter location.

[5DIGITS]

Just to be clear, I'm all for whatever testing anyone thinks of as far as evaluating components.
However I am a little doubtful as to how well an intake manifold can be flow tested, since plenum volume plays such a big role (in theory) and that will not be reflected in a static flow test. In the same way that runner length causing pressure waves to help flow would not be detected in a static test.
So while I think a flow test can tell you something, its going to be missing some important information in that regard.
And in order for the test to be used for relative comparison I would say test the BMF versus whatever else on the same flow bench, otherwise things start getting apples to oranges with different flow benches dont they?

What's missed on the flow bench is the large consideration of intake tuning pulses.
Although, flow benches are a calibrated devices with most deviation being realized from how the operator mounts the unit and incorporates air horns, at entrance points.

I agree..
I'd suggest that any 'A' 'B' comparisons between various components (stock vs BMF vs XXX, etc..) be made on the same bench.
This will establish a baseline to which others can compare to, especially in the case of comparing your results of a stock/ported two-piece vs others.
Additionally, consider testing that utilizes push and pull measurements (vacuum vs pressure), if the bench supports it.

[Vigo]

I agree with Shadow that unless you test a whole bunch of setups, the main thing you would be 'proving' would be that you can put the BMF on a mild setup without ruining it.

The real strength of the BMF would be on a higher-flowing head, with a bigger cam, at high rpm. Compare the BMF to a stock intake under those circumstances and you might see 50whp! Does that mean BMF buyers will gain 50whp? Not often. And while that is actually what it's 'for', i think most buyers won't actually use it that way, or wont get around to it for years. I wouldnt be comfortable placing bets on how soon i'll install mine.. but i still want it.

So what is most relevant to *prospective* buyers? Ease of install, bling factor, not causing drivability issues. The people who actually plan to use it for high flowing high rpm setups already know it's better than what they've got just by looking at it.

[Ondonti]

I agree with Shadow that unless you test a whole bunch of setups, the main thing you would be 'proving' would be that you can put the BMF on a mild setup without ruining it.

The real strength of the BMF would be on a higher-flowing head, with a bigger cam, at high rpm. Compare the BMF to a stock intake under those circumstances and you might see 50whp! Does that mean BMF buyers will gain 50whp? Not often. And while that is actually what it's 'for', i think most buyers won't actually use it that way, or wont get around to it for years. I wouldnt be comfortable placing bets on how soon i'll install mine.. but i still want it.

So what is most relevant to *prospective* buyers? Ease of install, bling factor, not causing drivability issues. The people who actually plan to use it for high flowing high rpm setups already know it's better than what they've got just by looking at it.

Even if it gains the most HP on the craziest setups, it could become a restriction in those setups. Everything in your setup has to be scaled properly to your goals. I would still rather be 75% awesome than 25% awesome if I had only 2 choices. You can't always afford or you don't always have the ability to go 100% perfect. I wouldn't demand you change your 75% awesome product so I could get 80% awesome and say your product was junk if you didn't meet the 80%. Anyone who complains has the chance to do things for themself.

[knownenemy]

The BMF won't become the choking point in a 2.2/2.5 intake system.

Our choking point will always be our heads.
We can port match them, and clean-up the combustion chambers,
open up the ports, etc, but we won't be able to get as "open" as the BMF.
No matter what we do.

Having said that;
The only possibility of the BMF becoming the restriction would be in the flange.
And although minimal, there IS room to move there.

As for testing; I still think back to back testing with other intakes would be a waste of time.
Unless the manifolds were tested on the same bench; by the same tech; in the same atmosphere; etc.

So if there are BMF owners who would like to know what they've gained with this intake,
I recommend taking it, with your old intake, to a reputable shop with a flow bench to note the results.
OR; build a flow bench to test it yourself.

For me; I intend to do some simple "flow path" testing to determine the air gets to all 4 cyls equally(or darn near).
My BMF was ordered without the side plates installed.
I wanted access to the inside of the plenum for possible baffle installation,
to try and direct the air intake to all 4 cyls equally, if necessary.
My intentions are to build a simple flow bench(very simple),
and use a vacuum leak smoke tester to SEE the airflow.
If adjustments are necessary,
I'll figure how to do that by placing different size/shaped baffles internally in the plenum.

It'll be quite a while(barring me hitting the lottery), before I get to these tests.
But when I do, I'll surely post what I learn. :)

[Shadow]

I didn't need any flow bench testing on the intake that is currently on the Charger to Know how well it works ;)

[acannell]

Even if it gains the most HP on the craziest setups, it could become a restriction in those setups. Everything in your setup has to be scaled properly to your goals. I would still rather be 75% awesome than 25% awesome if I had only 2 choices. You can't always afford or you don't always have the ability to go 100% perfect. I wouldn't demand you change your 75% awesome product so I could get 80% awesome and say your product was junk if you didn't meet the 80%. Anyone who complains has the chance to do things for themself.

help...

[knownenemy]

I didn't need any flow bench testing on the intake that is currently on the Charger to Know how well it works ;)
I think that the known volume of the intake
is about all the hard information we really needed to evaluate it pre-install.

Checking flow numbers, and measuring airflow IMHO is not even necessary.
That is; unless you're putting the BMF on an ALL-OUT sponsored Race car, trailer queen. lol

I agree Rob; just looking at the BMF with the naked eye
is proof enough for me that it outflows anything available. :partywoot:

[5DIGITS]

I agree with Shadow that unless you test a whole bunch of setups, the main thing you would be 'proving' would be that you can put the BMF on a mild setup without ruining it.
The real strength of the BMF would be on a higher-flowing head, with a bigger cam, at high rpm.
Compare the BMF to a stock intake under those circumstances and you might see 50whp!
Does that mean BMF buyers will gain 50whp? Not often.
And while that is actually what it's 'for', i think most buyers won't actually use it that way, or wont get around to it for years.
I wouldnt be comfortable placing bets on how soon i'll install mine.. but i still want it.

So what is most relevant to *prospective* buyers?
Ease of install, bling factor, not causing drivability issues.
The people who actually plan to use it for high flowing high rpm setups already know it's better than what they've got just by looking at it.

These are all great points - especially the gain factor when considering what it's being bolted to.

Bolt it on a stock vehicle and you may see 5-8HP.
On the other hand and like you said, bolt it on a strong breathing arrangement and the gains will be a function of the supporting hardware and related boost level.
I found this to be very much the case with the intake I designed, as it was worth far greater when the system demands were in place to utilize it.

To be very clear, previous indications of flow bench testing is mentioned only for those interested in the understanding why it works and/or to simply have the supporting numbers.
With this, testing is certainly not necessary to realize the benefits of any modified hardware especially when it simply works and exceeds previously used hardware.

The talent is and always will be, making it all work together no matter what is used.

[OmniLuvr]

help...

so I don't know if this is help or what, but after realizing what you did with the runners for a reason, and seeing them in person im fine with them, but I was wondering if you might do something about the 90* turn from the tb to the plenum. im thinking making the 90* turn be removable, like bolt on. so if you make the plenum a mustang or LS motor tb pattern, and bolt the 90* to that, so if you wanted to run either, you could bolt them directly to the plenum, or the 90* could be bolted on to utilize the stock style tb in a stock location? just an idea, its what im going to do to mine, which im going to have to ask you about in pm after work...

[acannell]

so I don't know if this is help or what, but after realizing what you did with the runners for a reason, and seeing them in person im fine with them, but I was wondering if you might do something about the 90* turn from the tb to the plenum. im thinking making the 90* turn be removable, like bolt on. so if you make the plenum a mustang or LS motor tb pattern, and bolt the 90* to that, so if you wanted to run either, you could bolt them directly to the plenum, or the 90* could be bolted on to utilize the stock style tb in a stock location? just an idea, its what im going to do to mine, which im going to have to ask you about in pm after work...

I definitely want to support a huge throttle body 65mm+. I did a bunch of research to find one that would be cheap and have minimal issues integrating its AIS and TPS to the stock electronics. In that case I would make a flange that would work for it and replace the existing TB flange.

Now if its desired to delete the 90 for flow reasons (less bends) then I think you would still need to space the TB bolting location off the plenum somewhat..IIRC most TB's need some clearance behind them. In that case, the elbow could be replaced with a short straight section and use the new flange.

[Vigo]

help...

I think i'm the only person who understood this because i remember what Ondonti's writing looked like before i understood it. :p

I think what he's referencing is that the BMF is the most useful to people who also have the most specific needs and it's a slippery uphill slope of diminishing returns if you try to accommodate them any more then the product already does. Anyone for whom the BMF is a restriction should already be at the point of being able to address the problem with their OWN fab skills and data gathering/analysis. In the same sense, anyone for whom the BMF does not pay obvius dividends probably has only themself to blame for matching parts poorly. The lack of 'bandwidth' in intake choices is certainly a problem, but it's not YOUR problem just because you are responsible for ONE of the options, so you shouldn't trouble yourself much with demands to build too many variations.

As i said, the only major sticking point that would give anyone legitimate grounds for complaint about the product is if it makes a mild setup run/drive poorly. I doubt it will and i think your car has already provided evidence against that.

These are just more longwinded ways of saying you dont NEED to do more testing.

[Ondonti]

I think i'm the only person who understood this because i remember what Ondonti's writing looked like before i understood it. :p

I think what he's referencing is that the BMF is the most useful to people who also have the most specific needs and it's a slippery uphill slope of diminishing returns if you try to accommodate them any more then the product already does. Anyone for whom the BMF is a restriction should already be at the point of being able to address the problem with their OWN fab skills and data gathering/analysis. In the same sense, anyone for whom the BMF does not pay obvius dividends probably has only themself to blame for matching parts poorly. The lack of 'bandwidth' in intake choices is certainly a problem, but it's not YOUR problem just because you are responsible for ONE of the options, so you shouldn't trouble yourself much with demands to build too many variations.

As i said, the only major sticking point that would give anyone legitimate grounds for complaint about the product is if it makes a mild setup run/drive poorly. I doubt it will and i think your car has already provided evidence against that.

These are just more longwinded ways of saying you dont NEED to do more testing.

Werd, except I have no idea what your epiphany up there really means.

I was trying to avoid giving real numbers because people seem to stick to those as some sort of fact when its just an thought exercise/example. Nobody will go around quoting 75% awesome.

You really can't build a perfect intake manifold for people looking for between 250-600whp AND with various RPM ranges. Some 8 valve setups rev low with lots of boost and some rev higher with more HP per psi boost. Intake runners are tuned length and diameter for specific rpm ranges and flow and if you actually optimise one rpm or flow requirement, you muff up the others. That is why some designers purposedly avoid resonance tuning.

I am the kind of person who would put a ridiculous intake manifold on a stock turbo stock head 8 valve just to do it as long as it was decently affordable. I could give two whoops if it only made me 1whp or 100.

Yes, the intake manifold can be a restriction even if the head is also a restriction. If Acannel made an intake manifold that was zero restriction to a 600whp setup then it wouldn't work as well on a 250whp setup. At some point the runner diameter is really going to hurt low rpm performance and 600whp setups will not perform well at low rpms no matter what their owners say. Anyone who has driven a high hp large turbo setup knows the huge difference between the rpms where you are out of boost and when you hit peak boost. The intake manifold that maximizes the 600whp setups at high rpms WILL make them feel even worse out of boost. Light cars don't notice this much but its still reality. Some high power people like optimized high rpm power, some like a more seamless powerband. No manifold can do all things perfectly. Being way better than stock is good enough for most people. For the price, its worth it when you think about how much time you would spend fooling around with your own design when you could have been making the money to pay for something that already might be better then what you would come up with. Having an affordable option messes up the whole justification of making a custom intake for most people (to save money).
2.2/2.5 also have a fairly standard modification path and ductwork where something like a 3.0 is all over the place between owners and I don't think I would be happy with a product made to fit one style of engine bay.
People who have sidewinder exhaust manifolds that might not clear should be able to make their own intake as that is very out of the norm and they have shown their own eagerness to go outside the box. Buck up.

[5DIGITS]

Werd, except I have no idea what your epiphany up there really means.

You really can't build a perfect intake manifold for people looking for between 250-600whp AND with various RPM ranges.
Some 8 valve setups rev low with lots of boost and some rev higher with more HP per psi boost.
Intake runners are tuned length and diameter for specific rpm ranges and flow and if you actually optimise one rpm or flow requirement, you muff up the others.
That is why some designers purposedly avoid resonance tuning.

I am the kind of person who would put a ridiculous intake manifold on a stock turbo stock head 8 valve just to do it as long as it was decently affordable. I could give two whoops if it only made me 1whp or 100.


Avoiding resonance tuning?.. I strongly disagree.
This would defy the very reason designers and manufacturers incorporate active tuning intake methods, to accomplish the best over-all area under the curve.
In this case, the "bigger is better" approach will come with the sacrifice of low and torque and the resulting aggressive injector boss taper, from the runner, will prematurely choke the system.
With the amount of positive effort and time being placed on this design (kudos :thumb:), a smaller runner with a less aggressive taper would potentially reduce cost and machining while improving the over-all result.. for all.
This considers that there is only so much that can be force fed to an 8V.. anything greater will have diminished returns on investment.

[knownenemy]

Asa, here's how this will go:
We'll discuss testing the BMF ad nauseum; there will be discussion, arguments, resentments formed, props given, etc.
And when it's all said and done, the only thing that will bring actual results is practical application.

Once there are enough members who've installed, and tuned with the BMF,
surely there will be suggestions and experience based comments to draw from.
What we know now is the BMF out does any factory manifold in volume, and potential.

I think the design came out beautifully, and the actual data we've got thus far
(Asa'a close to factory setup, and one other member that I know of) has been great.
The most incredible thing about the BMF is its potential and versatility.
It's becoming more evident that the BMF can be used for 200HP or 650HP+ setups with good results.
This isn't all that surprising, in that we've seen the factory 2pc. be versatile; just not AS versatile.

The design of the BMF is just something we ALL have been trying to do with the factory 2pc for years!
We've been porting, cutting, smoothing, and opening the 2pc. as much as possible forever.
All the BMF did was increase how far we could go.
If you picture the last 2pc. you've worked on(this is to anyone who has experience with a 2pc.),
the BMF is simply where you would have ported the 2pc. to, if the material was there.

My rant here may be due in part to the fact that my BMF lays quietly in a cabinet drawer,
as I progress on other parts of the build, but when I get to engine tuning, I can't wait to post results I find.

And lastly;
Maybe a thread titled, "BMF results. What's working in your setup?", would be a good idea.
This way members who have installed their BMF could post how they've gotten the best performance from it. :grouphug:

[acannell]

Maybe a thread titled, "BMF results. What's working in your setup?", would be a good idea.
This way members who have installed their BMF could post how they've gotten the best performance from it. :grouphug:

Im trying to generate some data for all of us ASAP. I already have some data logged, but it was with the BMF prototype and a very unique tubular header, so Im not sure how it can be interpreted, although it was at stock boost levels so the header probably didnt affect things much.

But I'm going to go forward with a production-BMF, stock exhaust manifold, along with a 0.63 chrysler housing, small turbo, and a G head with 58mm TB. But while the car is apart (lol) I'm working on a swingvalve/downpipe product so it may be awhile. I think POPE had some builds planned for early this year, maybe the BMF customers will have data before I do.

I agree, the most utility will be with how to adjust the tune and cam to get the most out of a huge intake at high flow levels. Thats where the TM world starts to get a little murky, cam and tune design. Time to raise the bar!

[acannell]

heres the data I have so far with the BMF prototype

http://i242.photobucket.com/albums/ff197/acannell/daytonarun_zps8ad8c578.png

[5DIGITS]

With the amount of positive effort and time being placed on this design (kudos :thumb:), a smaller runner with a less aggressive taper would potentially reduce cost and machining while improving the over-all result.. for all.
This considers that there is only so much that can be force fed to an 8V.. anything greater will have diminished returns on investment.

Again, it's not difficult to out do a 2pc intake unless major reconstructive surgery is performed.
What's being provided is positive reinforcement with constructive suggestions that can improve the design (for all 200 -600HP) while minimizing cost.
Hopefully this is being received as it's genuinely being sent.

[acannell]

I think some perspective would help here, since there really isn't any data on how runner length or what have you would specifically help the 2.2/2.5. Its all conjecture, but reasonable. What I'm saying is nobody has played with runner length on our engines, recorded data, and then presented it.

Our stock intake is MICRO. As in micro-SCOPIC. The throttle body is teeny-weeny. Unless the idea is that velocity is SO critical and flow is totally not, I dont see why our stock intakes are even on the map as far as modified-turbo-engine. Once you start trying to get power out of our cars, all the holes need to get ALOT bigger.

Sitting next to my daytona is an 09 LS3 Corvette, and comparing the two make me ponder some things.

Take the LS3, a 2valve per cylinder, single cam engine, with fixed valve timing, which puts out 424ft lbs of torque at 4600rpm. Our 2.2/2.5 probably does that at what, high 20's psi with a full set of typical modifications?

But whats funny is, we will do that on our TM's and think a 58mm throttle body and a 3" exhaust are "BIG".

The chevy does it with a 90MM throttle body and TWO 2.5" exhausts. And thats on a N/A engine! How big of a TB and exhaust is justified for a 500hp 2.2/2.5 TM? At least as much as a N/A 450hp engine right? But we still work in the land where anything beyond 58mm requires special fabrication skills and a 3" exhaust has somehow become the standard. ???

See a pattern here? The holes need to get ALOT bigger on our cars. We are just wasting energy pumping air through all those little holes. We are nowhere NEAR the point where things have gotten too big and all the air is going too slow. Look at the LS3 combustion chamber, it looks VERY similar to our ancient swirl head, just smoother. Oh, except one thing, the intake valve is 55mm and the exhaust valve is 40mm. Thats like +15mm and +5mm on the exhaust.

I say we can keep going bigger and bigger. The real hard limit is how big of ports and valves you can put in our little bores and heads. I think thats where Warren Stramer came in with a few atom bombs and made things so.

[zin]

The key is in removing what I call the point of "constipation". The BMF does it in regards to the intake, if the rest of the intake system is in line with performance, the head will be the limiting factor, assuming an adequate cam is in place.

Mike

[acannell]

Another way to look at it: we're moving the same amount of air on our heavily boosted, ancient 2.2/2.5 as a modern V8, but all our pipes are 1/2 the size. How does that make sense? It doesnt. If the pipes being smaller had some kind of velocity/swirl effect, you'd see it on the modern engine, where they would have had decades more experience and alot better ways of simulating and manufacturing that. But instead, you see big holes.

And I know lots of people hate chevy, I just dont know anything about the modern dodge engine. I'm sure its exactly the same situation on the 6.2L V8 Hemi. (Im pretty sure there is/was one in the past few years making the same mid 400's hp).

[zin]

Like most things, the closer you look the more complex it gets.

Big holes flow big air, but that's no guarantee of big power, what happens after the valve is often more important than the volume of flow.

Depending on the port angle, etc, a smaller hole with a higher quality flow will make more power than the head with big flow numbers.

There's actually formulas to calculate tuned lengths and port diameters to optimize resonant tuning and port velocities, as well as port taper.

I'll try to find my notes and post the formulas.

Mike

PS none will be exact, lots of variables so still a little trial and error if you want it exact, but I don't think that matters to us.

[Ondonti]

Avoiding resonance tuning?.. I strongly disagree.
This would defy the very reason designers and manufacturers incorporate active tuning intake methods, to accomplish the best over-all area under the curve.


I don't think many active intake manifolds are an attempt at actual resonance tuning, just what people mistake resonance tuning for. Simply optimizing the velocity of the intake charge. Spend the time matching runner diameter and length for desired peak hp and the shape of the HP curve. One sets the peak hp rpm, one rocks it on the peak rpm biasing low or high rpm power. Resonance tuning is well beyond that and not related. You ignore it unless you have a massive budget because you will fail over and over.

[Ondonti]

Nobody has to use their listening ears but here is an example of real life intake manifold tuning. People jump off into resonance tuning when that is another stratosphere of complication and most people have not understood the basics.

You also determine runner size by your valve size and how many valves per port. Then you fine tune your GUESS.
This should make it clear that the perfect manifold for one person is not perfect for another depending on peak hp RPM goal and desired powerband shape. It should also be clear that if you fudge something in the middle it can work well for most setups. If you had extreme short and large runners it would be a problem for most people just like extreme long and small runners would be a problem for most people. Those combinations would work for some people though!
If you really get into this, you might realize your motor has the wrong size valves for your displacement. All these problems come up long before you touch resonance tuning.

http://www.rotaryeng.net/PIPE_V_LENGTH_DIAMETER.JPG

[Reaper1]

Brent, I agree that most people building their own intakes, and probably most small performance shops don't really build intakes to use resonance tuning...or at least not well. However, to say that OEM's don't use it is just wrong. We all know that resonance tuning has been something OEM's have been doing since the 413 long ram. The variable intakes that are being used in today's cars use this same idea and are able to spread the advantage of their design over a broader range of operation. I'm not saying they all work this way, but a majority of them do.

Then there are people that disable the variable intake systems and just open the thing all the way. When this is done the owner no longer cares about the lower end drivability of the car, but instead is focused only on top end performance. Now, because typically there are other changes done to the system the low end losses can come out in a wash so they are never felt.

Resonance tuning a turbo vehicle isn't exact anyway because the intake conditions are dynamic, namely pressure and temperature. So, you can iterate until you are blue in the face and you will still only come up with something that is "close". It will only work they way it was designed in that one specific situation. Anything outside of those parameters and it is doing something different. I'm not saying don't do it. I'm saying there is no way to get it "right" for everybody when it's impossible to do for even your own car!

[Vigo]

I agree with Brent that resonance tuning is WELL beyond what we should actually be worrying about. I think it falls under my statement about diminishing returns trying to cater to too many different needs, and since the port size/shape and valve size will be different in many of the apps these BMFs will be used in, the whole concept of resonance tuning is basically completely irrelevant to this conversation. Just an opinion, of course.


Take the LS3, a 2valve per cylinder, single cam engine, with fixed valve timing, which puts out 424ft lbs of torque at 4600rpm. Our 2.2/2.5 probably does that at what, high 20's psi with a full set of typical modifications?

But whats funny is, we will do that on our TM's and think a 58mm throttle body and a 3" exhaust are "BIG".

The chevy does it with a 90MM throttle body and TWO 2.5" exhausts. And thats on a N/A engine! How big of a TB and exhaust is justified for a 500hp 2.2/2.5 TM? At least as much as a N/A 450hp engine right?

Well i think it is closer than you are thinking. Several points:
A. If you 'ballpark' that every additional atmosphere of pressure makes an engine behave twice as large, twenty something psi on a 2.5 comes out to the same displacement as a 6.2 ls3.

B. Two 2.5" pipes only have about 30% more flow area than a single 3", and the real reason everybody stops at 3.0 is because that's as big as will fit between the fuel tank and rear suspension so any 'full exhaust' has to pinch down to 3" there unless you dump a lot of effort into it.

C. Throttle bodies on turbos are different from throttle bodies on N/As because they flow a higher density gas. Turbo throttle bodies basically are just another part of the plumbing between the compressor outlet and the plenum area. That size is not a big performance issue unless you cause velocity to go up to 'sonic choke' where it enters the plenum. That's my basic understanding. The compressor INLET is much more comparable to an n/a throttle body because it only has one atmosphere of pressure pushing into it. If you look at the turbo inducer diameters of 450hp setups they are typically in the high 50s mm and up size range. It would be 'better' if they were bigger except that that necessitates huge mass increase on the compressor wheel. It can also get away with being smaller than an n/a throttle body because the compressor wheel is creating a lower pressure area on the backside of that 'orifice' than an n/a engine creates behind a throttle body so the pressure differential is larger even though the inlet pressure is the same.

I could be wrong about some of this but i think i am mostly right. :p

[acannell]

A. If you 'ballpark' that every additional atmosphere of pressure makes an engine behave twice as large, twenty something psi on a 2.5 comes out to the same displacement as a 6.2 ls3.


Im not sure what to make of this fact. Please go on...



B. Two 2.5" pipes only have about 30% more flow area than a single 3", and the real reason everybody stops at 3.0 is because that's as big as will fit between the fuel tank and rear suspension so any 'full exhaust' has to pinch down to 3" there unless you dump a lot of effort into it.


Well its more like 38%, and 38% is alot! Plus, I think the argument can be made that an NA engine may actually benefit from some backpressure depending on how its designed, while in a turbo engine, especially at extreme boost levels, backpressure just consumes power. And the LS3 uses two 2.5 exhaust stock. Plus, IIRC, two pipes flow better than one pipe, cross sectional area remaining the same. What I'm saying is, we should be making the exhaust as huge as possible, 3" is not a place to stop just because of the fitment situation near the trunk. We should be going even bigger than what you'd find on an LS3, and its backwards, the LS3 is alot bigger than where we typically stop. These are TM's! Its hacksaw time or dump it out the side, we've got flow to think about lol




C. Throttle bodies on turbos are different from throttle bodies on N/As because they flow a higher density gas. Turbo throttle bodies basically are just another part of the plumbing between the compressor outlet and the plenum area. That size is not a big performance issue unless you cause velocity to go up to 'sonic choke' where it enters the plenum. That's my basic understanding. The compressor INLET is much more comparable to an n/a throttle body because it only has one atmosphere of pressure pushing into it. If you look at the turbo inducer diameters of 450hp setups they are typically in the high 50s mm and up size range. It would be 'better' if they were bigger except that that necessitates huge mass increase on the compressor wheel. It can also get away with being smaller than an n/a throttle body because the compressor wheel is creating a lower pressure area on the backside of that 'orifice' than an n/a engine creates behind a throttle body so the pressure differential is larger even though the inlet pressure is the same.

I could be wrong about some of this but i think i am mostly right. :p

I'm actually not sure what to think about throttle body size. 90mm???? I just now that that is ALOT bigger than a 58mm, 240% bigger in fact. Wayyy in a whole nother league. It must have something to do with power but Im not sure what. At the very least, a small TB is a literal bottleneck among other intake plumbing that should be as huge as possible.

I just know that unless things are carefully engineered, the smaller a pipe the more power its consuming, anywhere in a turbo engine under boost. If we were carefully sizing runners and truly trying to time exhaust pulses in a tubular header then maybe purely bigger would not be better, but even then I think its just a matter of scale. You can still make it bigger you just have to scale up to where your timing/resonance effects are matched to the new flow level/big cross section pipes.

Do we have any data, even second-hand reports, that big pipes hurt performance on our 2.2/2.5 at 300hp+?

Also, the supercharged version of the LS3, the LS9, still uses the same size throttle body and makes 595 ft lbs. Still single cam, still 2 valves per cylinder, still fixed valve timing. Except they went up to double 3" exhaust pipes.

[iTurbo]

I know I'm way out of my league posting in this thread at this point. But as an anecdotal report I will say that I once used a BIG NPR intercooler and 2.75" intercooler pipes on my old Omni GLH which used a "2.5L TII" configuration. Stock TII turbo/head/manifolds/TB. The boost response was damn near instantaneous and hit 270 ft/lbs on a dynojet at 14 psi boost. The inclusion of several more feet of larger 2.75" piping and the huge intercooler didn't seem to have any affect on lag whatsoever. That car was totally point and shoot and very fun to deliver pizza in.

52723

[Ondonti]

Brent, I agree that most people building their own intakes, and probably most small performance shops don't really build intakes to use resonance tuning...or at least not well. However, to say that OEM's don't use it is just wrong. We all know that resonance tuning has been something OEM's have been doing since the 413 long ram. The variable intakes that are being used in today's cars use this same idea and are able to spread the advantage of their design over a broader range of operation. I'm not saying they all work this way, but a majority of them do.

Then there are people that disable the variable intake systems and just open the thing all the way. When this is done the owner no longer cares about the lower end drivability of the car, but instead is focused only on top end performance. Now, because typically there are other changes done to the system the low end losses can come out in a wash so they are never felt.

Resonance tuning a turbo vehicle isn't exact anyway because the intake conditions are dynamic, namely pressure and temperature. So, you can iterate until you are blue in the face and you will still only come up with something that is "close". It will only work they way it was designed in that one specific situation. Anything outside of those parameters and it is doing something different. I'm not saying don't do it. I'm saying there is no way to get it "right" for everybody when it's impossible to do for even your own car!

I will stick with people saying "resonance tuning" when they really mean "optimizing port velocity and flow at various RPMS."

Yes there might be some resonance tuning but what people understand of resonance tuning and what manufacturers actually do is different. People seem to think there is a magic setup for resonance and there is not, also I don't know any variable intakes that could actually meet different resonances. Slowly opening up a butterfly in a shorter runner is only going to change port flow and velocity AND mess up all the pulses in the intake. Its more like you design an intake manifold and avoid creating a situation where its good at one RPM and suffering at others. Its more important to get a broad improvement than a great improvement in a small RPM window. That is what manufacturers do, and that is not what people think of when it comes to resonance tuning. True resonance tuning is something left for all the people dreaming of racing their CVT's with the million dollar budgets. No need to worry about the powerband then.

If you use the logic from the chart I posted above, you would mostly hope that resonance does not either mess up your powerband or give a weird momentary uptick in power (not good in a production car).

Follow the article where I found that picture and it talks about using rotary engines in airplanes where you have little room for a proper intake. You can make 300hp on a carbed stock RX8 rotary engine at 9000 rpms with a proper intake manifold...but, tip speed velocity with standard gearing of the propelar means that you are usually limited to 7500 rpms where a good long runner intake might make 240hp but be way down on power in the lower rpms if forced to use a very short runner manifold. The difference in power available to the RX8 motor simply on carburetor and intake manifold was 150 to 300hp. The intake manifold soley responsible for moving the peak HP. They kept runner diameter constant in their examples. They found that it was better to use a "p port" that CANNOT be perfect but for fitment it outdoes what just about anyone would pull off trying to make a proper mathmatical intake manifold.
Basically that means don't shoot for the starts and hope to at least hit the moon. Shoot for what will get you where you want to be.

The 3.0 intake manifold versions certainly have had some designs meant to promote resonance tuning...what do we do with those? Remove them and get nice power gains that the manufacturer didn't care about. Manufacturers certainly only ever cared the most about maximizing economy at cruise rpms and minimizing emissions. On the Hellcat they were reported to be struggling with how to keep emissions in check where the less powerful similar displacement Chevy and Fords have no such problems. Obviously somebody designed something too aggressively for the higher rpms.

To even talk about resonance tuning but skip talk of diameter and length of runners for various peak power and powerband goals is a sure recipe for getting nowhere. That is like building a fueling map without knowing what injector size or fuel pressure you will run. There are a lot of cool technologies and theories that can be applied to get small gains but the budget required and the inability to apply these things equally to each persons setup makes them a bad investment. How can we have threads saying ported stock exhaust manifolds are quite decent but try to resonance tune an intake manifold when we have the standard "I don't want to pay for anything" turbododge budgets.

"(Resonance tuning)'s but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more..." - famous guy.

Basic intake manifold design would be as simple as this,

Determine displacement per cylinder
Determine valve size based on displacement and peak HP goals
determine runner diameter and length based on valve size PLUS peak hp and powerband goals.
See how much room you have for a plenum.

People skip all that and shoot for optimizing complete crap. Trumpets on the wrong diameter runners and equal distribution schemes for runners that are too long/short.

[Vigo]

I agree completely with Brent. This goes back to the things he also says about Megasquirt being designed by people who like to tinker with code more than they like having functional cars. We need to get off the resonance tuning kick. i don't care about a tiny gain in a tiny rpm window that's only going to work right on 1% of customer's vehicles. Complete waste of breath!


I'm actually not sure what to think about throttle body size. 90mm???? I just now that that is ALOT bigger than a 58mm, 240% bigger in fact. Wayyy in a whole nother league. It must have something to do with power but Im not sure what. At the very least, a small TB is a literal bottleneck among other intake plumbing that should be as huge as possible.

Well what is there to think about? I feel like my post addressed a lot.... I dont WANT 4" intercooler plumbing, and that itself would be the only justification for having a 90mm throttle body on our turbo engines. Think about your charge plumbing. Now pick a spot in your charge plumbing and imagine moving your throttle valve there. Now it's your throttle body. Why does it need to be 90mm? Our throttle bodies are just part of our charge plumbing that happen to have an air valve in them. They don't need to be the same size as an n/a engine because they flow a higher density gas. Making them the same size as a giant n/a engine on our tiny displacement would just cause low speed drivability problems that would be easy to get around with drive by wire but NOT easy to get around with an old fashioned throttle cable. What would we gain? Very little. Don't think about the throttle body as 'intake' plumbing at all. The 'intake' as it would be on an n/a engine, stops at the compressor inducer area. We can make that bigger but we will kill turbo response by going anywhere near n/a throttle body size. A 90mm turbo inducer would literally NEVER spool on a 6000 rpm 2.5L.

I think there is some usefulness to comparing to n/a stuff but only if you can put it in proper context and recognize the differences.

As for people being willing to chop up and modify their fuel tanks, good luck. Some people are willing to run side exit and some arent, and even side exit has it's complicating factors because even a 3" pipe out the side limits ground clearance pretty severely. It's basically not compatible with my desires for lowering. Ive had 2 3" side-exit exhausts (still running one of them) and have nothing bad to say about it, it just has limitations depending on what ELSE you want to accomplish with your vehicle. What would be nice to talk about instead of jamming a bigger pipe next to the fuel tank would be taking something like your dual thermocouple gauge, measuring temps in the downpipe and then next to the fuel tank, and then calculating the change in density and whether or not we can go to 4" downpipe and 4" down the tunnel and still have the same 'mass flow' through a 3" pipe around the fuel tank because the exhaust has shrunk that much due to cooling.

[GLHNSLHT2]

I agree completely with Brent. This goes back to the things he also says about Megasquirt being designed by people who like to tinker with code more than they like having functional cars. We need to get off the resonance tuning kick. i don't care about a tiny gain in a tiny rpm window that's only going to work right on 1% of customer's vehicles. Complete waste of breath!



Well what is there to think about? I feel like my post addressed a lot.... I dont WANT 4" intercooler plumbing, and that itself would be the only justification for having a 90mm throttle body on our turbo engines. Think about your charge plumbing. Now pick a spot in your charge plumbing and imagine moving your throttle valve there. Now it's your throttle body. Why does it need to be 90mm? Our throttle bodies are just part of our charge plumbing that happen to have an air valve in them. They don't need to be the same size as an n/a engine because they flow a higher density gas. Making them the same size as a giant n/a engine on our tiny displacement would just cause low speed drivability problems that would be easy to get around with drive by wire but NOT easy to get around with an old fashioned throttle cable. What would we gain? Very little. Don't think about the throttle body as 'intake' plumbing at all. The 'intake' as it would be on an n/a engine, stops at the compressor inducer area. We can make that bigger but we will kill turbo response by going anywhere near n/a throttle body size. A 90mm turbo inducer would literally NEVER spool on a 6000 rpm 2.5L.

I think there is some usefulness to comparing to n/a stuff but only if you can put it in proper context and recognize the differences.

As for people being willing to chop up and modify their fuel tanks, good luck. Some people are willing to run side exit and some arent, and even side exit has it's complicating factors because even a 3" pipe out the side limits ground clearance pretty severely. It's basically not compatible with my desires for lowering. Ive had 2 3" side-exit exhausts (still running one of them) and have nothing bad to say about it, it just has limitations depending on what ELSE you want to accomplish with your vehicle. What would be nice to talk about instead of jamming a bigger pipe next to the fuel tank would be taking something like your dual thermocouple gauge, measuring temps in the downpipe and then next to the fuel tank, and then calculating the change in density and whether or not we can go to 4" downpipe and 4" down the tunnel and still have the same 'mass flow' through a 3" pipe around the fuel tank because the exhaust has shrunk that much due to cooling.


I think to simplify things a Vette engine is what these days? 5.7 liters? 6.2 for a Hellcat. More than double our displacement. So you need a TB that's double our size. Double our 58mm TB for a 5.0L engine and you have one with a 114mm butterfly. So I don't think the 58 is really too small to feed our 2.2/2.5L motors. IMO opinion from running one on my Plenum'd 2 piece on a 2.5 it was maybe a bit too big. I had an adapter made to go back to a 52 but only ever tested it in the driveway where the 52 seemed to rev just as quick as the 58 did. Maybe once I get my new setup installed I can test out the differences again as I'll be able to pull the intakes without pulling the head. So I can run a stock 1 piece, stock 2 piece, Plenum'd 2 piece and Asa's intake all on the same head.

The 58mm had wicked throttle response, so much so that if you crossed an intersection that had studded tire ruts crossing both ways you had to brace your foot against the center tunnel or you'd look like you were trying to get going with a clutch that you didn't know how to operate it would bounce that quickly. I liked it sometimes and sometimes it was just too much. Most of the time I like it was in 3rd-5th gears. 1st and 2nd were almost too short for it and I had the rev limiter up to 7200rpms.


Vigo, to get 4" exhaust past the Tank you don't chop it, you install 2.5" coil-over springs back there.

[5DIGITS]

All great points here when discussing NA vs pressurized.
NA will require a larger TB and volume for obvious reason - The engine is left to 'pull' the air with the least amount of restriction or pressure drop.
On the contrary, pressurized manifolds require less in size due to the very assistance of 'push' from the turbo.

With regards to the taper at the mounting bosses on the BMF, the taper becomes a choke point because its confined to a short travel distance.
This will occur because the taper/reduction is constrained within a short distance during linear air travel.
If the same reduction was spread across the entire runner length, this would not be such an issue but because its isolated to 1.5-2.0" of the intake path it becomes highly conducive to turbulence, its resulting restriction and greatly disrupts any such intake tuning.
The ideal circumstance would have the runner at a 7 degree taper across 12 inches but since that's not possible for numerous reasons, reducing the runner diameter and the localized aggressive taper at the injector boss will gain flow and intake pulse amplitude across the entire powerband.
The result for ALL applications from mild to aggressive will be greater area under the curve.. regardless if its a stock head or a fully ported big valve application, mild or off the charts boost.
Bigger is not better in this case.

[acannell]

I think to simplify things a Vette engine is what these days? 5.7 liters? 6.2 for a Hellcat. More than double our displacement. So you need a TB that's double our size. Double our 58mm TB for a 5.0L engine and you have one with a 114mm butterfly. So I don't think the 58 is really too small to feed our 2.2/2.5L motors.

I think the mass air flow is more important for this calculation that just static displacement. Remember we are comparing torque levels. So 6.2L LS3 w/ 420 ft/lbs vs 2.2/2.5 at upper 20s psi with full mods at same torque level.



IMO opinion from running one on my Plenum'd 2 piece on a 2.5 it was maybe a bit too big. I had an adapter made to go back to a 52 but only ever tested it in the driveway where the 52 seemed to rev just as quick as the 58 did. Maybe once I get my new setup installed I can test out the differences again as I'll be able to pull the intakes without pulling the head. So I can run a stock 1 piece, stock 2 piece, Plenum'd 2 piece and Asa's intake all on the same head.

The 58mm had wicked throttle response, so much so that if you crossed an intersection that had studded tire ruts crossing both ways you had to brace your foot against the center tunnel or you'd look like you were trying to get going with a clutch that you didn't know how to operate it would bounce that quickly. I liked it sometimes and sometimes it was just too much. Most of the time I like it was in 3rd-5th gears. 1st and 2nd were almost too short for it and I had the rev limiter up to 7200rpms.


Vigo, to get 4" exhaust past the Tank you don't chop it, you install 2.5" coil-over springs back there.


Another thing to chew on: lets say we cant fit a 4". Can we fit two 2.5" or two 3"? Not that much more work or $$$ if you do 4" down to the cat and then split into two from there. :eyebrows:

[acannell]

Okay the similar dodge engine is the 6.1L hemi used in the SRT8 challenger until 2010. 420ft lbs at 4800rpm.

Curious, I dont think Ive ever seen anyone mention it on these forums. Maybe Im just imagining that but I swear there just never seems to be any comparison of the 2.2/2.5 to the modern dodge engines

[acannell]

heres so CC pics:

first: Chrysler 6.1L V8 (slightly smoothed and radiused)
second: LS3
third: 2.2/2.5 swirl
fourth: 2.2/2.5 bathtub "G"

http://image.hotrod.com/f/82298046+w660+h440+cr1/hemi-build-cylinder-heads-bowl.jpg
http://speednik.com/files/2013/09/22-640x426.jpg
http://www.turbododge.com/forums/attachments/parts-sale/41265d1305861358-ported-782-swirl-head-img_0981.jpg
http://i164.photobucket.com/albums/u36/fmd123/20130221_112107.jpg

[acannell]

All great points here when discussing NA vs pressurized.
NA will require a larger TB and volume for obvious reason - The engine is left to 'pull' the air with the least amount of restriction or pressure drop.
On the contrary, pressurized manifolds require less in size due to the very assistance of 'push' from the turbo.


Sorry, completely wrong. There is no difference between how air is flowing between a pressurized manifold and a "NA" manifold. Both are under pressure. One is under atmospheric, the other under atmospheric + additional boost pressure. They both "push" or "pull" , in exactly the same way. The piston moves down and creates a volume which gas expands in because the gas is under pressure.

Just because the boost gauge reads "0" without a turbo does not mean there is not pressure in the plenum. There is 1 bar of pressure.



With regards to the taper at the mounting bosses on the BMF, the taper becomes a choke point because its confined to a short travel distance.
This will occur because the taper/reduction is constrained within a short distance during linear air travel.
If the same reduction was spread across the entire runner length, this would not be such an issue but because its isolated to 1.5-2.0" of the intake path it becomes highly conducive to turbulence, its resulting restriction and greatly disrupts any such intake tuning.
The ideal circumstance would have the runner at a 7 degree taper across 12 inches but since that's not possible for numerous reasons, reducing the runner diameter and the localized aggressive taper at the injector boss will gain flow and intake pulse amplitude across the entire powerband.
The result for ALL applications from mild to aggressive will be greater area under the curve.. regardless if its a stock head or a fully ported big valve application, mild or off the charts boost.
Bigger is not better in this case.

Calling things a "choke" point without referencing them to something else doesn't mean anything. Compared to what? And how much of a difference does it make? You have to specify scale to even start to make meaningful comparisons between intake geometries. I think the 2 piece runner, casting and all, could almost fit INSIDE the BMF runner. At some point sheer cross sectional area dominates any sort of taper effect.

BTW, the BMF head flange taper is not "aggressive" Its actually quite mild. If there is going to be an aggressive taper to deal with its the head port.

http://www.exoticelectron.com/bmfi_cad_cross.jpg

[GLHNSLHT2]

Also, the supercharged version of the LS3, the LS9, still uses the same size throttle body and makes 595 ft lbs. Still single cam, still 2 valves per cylinder, still fixed valve timing. Except they went up to double 3" exhaust pipes.



You said it right here. The n/a and SC use the same size TB. Both are 6.2 liters. Almost triple our displacement. Yet one makes a lot more power than the other because one is boosted.

If anything on this intake needs to be bigger IMO it's the neck from the TB to the plenum, and that's to smooth and SLOW the air down into the plenum.

[85boostbox]

Resonance tuning, and port velocity are two different things. Trust me, I started a thread on here about intakes a while ago and my thoughts were exactly wrong.

Resonance tuning, ( harmonics) are when the valve snaps shut and the sudden stop or flow of air sends a shockwave back up the runner. The different lengths give you how far or how long it lasts. That is why short runners work better for top end, the engine is spinning so fast that the wave doesn't really effect air flow. Complete opposite for long runners.

Port velocity doesn't change in the intake more or less until the valve opens. I thought the same thing that air moves quicker in a boosted application. I was wrong, and did more research. Plus from a few members here to explain. Only increased velocity in a boosted application is right before the valve when it opens. Everything else is just pressure. I'll see if I can find my thread later and post it up here.

[5DIGITS]

Okay the similar dodge engine is the 6.1L hemi used in the SRT8 challenger until 2010. 420ft lbs at 4800rpm.

Curious, I dont think Ive ever seen anyone mention it on these forums. Maybe Im just imagining that but I swear there just never seems to be any comparison of the 2.2/2.5 to the modern dodge engines

Maybe by comparison of HP but comparing the demand placed on HP vs displacement and the related distribution of 4 cylinders vs 8 within a single plenum is unjustified.

[5DIGITS]

Resonance tuning, and port velocity are two different things. Trust me, I started a thread on here about intakes a while ago and my thoughts were exactly wrong.
Resonance tuning, ( harmonics) are when the valve snaps shut and the sudden stop or flow of air sends a shockwave back up the runner.
The different lengths give you how far or how long it lasts.
That is why short runners work better for top end, the engine is spinning so fast that the wave doesn't really effect air flow. Complete opposite for long runners.
Port velocity doesn't change in the intake more or less until the valve opens.
I thought the same thing that air moves quicker in a boosted application.
I was wrong, and did more research. Plus from a few members here to explain.
Only increased velocity in a boosted application is right before the valve when it opens.
Everything else is just pressure.
I'll see if I can find my thread later and post it up here.

Well said.
Even under boosted applications a negative depression is realized or the expense and development time to make the two-piece would not have occurred and the difference between a log, single piece, or the longer runner two-piece wouldn't have mattered but they do.

[5DIGITS]

Sorry, completely wrong. There is no difference between how air is flowing between a pressurized manifold and a "NA" manifold. Both are under pressure. One is under atmospheric, the other under atmospheric + additional boost pressure. They both "push" or "pull" , in exactly the same way. The piston moves down and creates a volume which gas expands in because the gas is under pressure.
Just because the boost gauge reads "0" without a turbo does not mean there is not pressure in the plenum. There is 1 bar of pressure.

True - to a point.
The pulses ARE affected by increased pressure (above atmospheric), velocity is higher and the frequency and amplitude in which all this occurs is different.


Calling things a "choke" point without referencing them to something else doesn't mean anything.
Compared to what?
And how much of a difference does it make?
You have to specify scale to even start to make meaningful comparisons between intake geometries.
I think the 2 piece runner, casting and all, could almost fit INSIDE the BMF runner.

Its being referenced to the proportions within it's own intake.
After numerous mention, these are not derogatory comments to belittle whats being attempted here.
Stating that the proportions are competing against each-other simply identifies that the runner volume, on this intake, compared to the available area at the head entrance will support premature turbulence, on this intake.
Again, it's being compared to nothing but itself.


At some point sheer cross sectional area dominates any sort of taper effect.

Not at all - the exit from the intake is only as large as the entrance to the head.
What merging high density in a short distance results in is elevated velocity - this commonly results in loss of flow and a subsequent choke within the system.
It's why the common household toilet plugs, metaphorically speaking.



BTW, the BMF head flange taper is not "aggressive" Its actually quite mild. If there is going to be an aggressive taper to deal with its the head port.

Not true - In fact, having a preceding choke point before the downward turn in the head will actually relieve the head of some it's demand.

I cannot emphasize it enough, the points being raised are not to diminish the effort being put forth but to identify that bigger is not always better.
In this case, somewhere between the runner size currently being used on this intake and the available area within the cylinder head port is an ideal arrangement.
Respectfully, anything larger than whats required to accomplish the task is detrimental and a step in the wrong/wasteful direction.

[5DIGITS]

You said it right here. The n/a and SC use the same size TB. Both are 6.2 liters. Almost triple our displacement. Yet one makes a lot more power than the other because one is boosted.
If anything on this intake needs to be bigger IMO it's the neck from the TB to the plenum, and that's to smooth and SLOW the air down into the plenum.

Exactly !
How large would the TB need to be if the SC engine made the same HP as the NA engine?.. smaller perhaps?
Also consider that intake pulses occur at twice the frequency of a four cylinder engine and therefore the tuning pulses will also impact tuning amplitude.. greater is typical.

Also agreed is the neck.. a wider turning floor (the left side of the TB) will improve this and welding/porting can provide what's needed.

[85boostbox]

http://www.turbo-mopar.com/forums/showthread.php?t=69668


Long winded, but TONS of useful I information from a LOT of knowledgeable people on this board.

[acannell]

True - to a point.
The pulses ARE affected by increased pressure (above atmospheric), velocity is higher and the frequency and amplitude in which all this occurs is different.

Its being referenced to the proportions within it's own intake.
After numerous mention, these are not derogatory comments to belittle whats being attempted here.
Stating that the proportions are competing against each-other simply identifies that the runner volume, on this intake, compared to the available area at the head entrance will support premature turbulence, on this intake.
Again, it's being compared to nothing but itself.

Not at all - the exit from the intake is only as large as the entrance to the head.
What merging high density in a short distance results in is elevated velocity - this commonly results in loss of flow and a subsequent choke within the system.
It's why the common household toilet plugs, metaphorically speaking.

Not true - In fact, having a preceding choke point before the downward turn in the head will actually relieve the head of some it's demand.

I cannot emphasize it enough, the points being raised are not to diminish the effort being put forth but to identify that bigger is not always better.
In this case, somewhere between the runner size currently being used on this intake and the available area within the cylinder head port is an ideal arrangement.

Respectfully, anything larger than whats required to accomplish the task is detrimental and a step in the wrong/wasteful direction.

12 inch long runners would put the plenum behind the firewall. The phrase "7 degree taper over 12 inches" doesnt really make sense anyways. The taper angle is the taper angle, independent of length. The BMF taper angle is about 6 degrees and the taper is about 1.8 inches long.

Toilets have nothing to do with engines. Water is not compressible. The physics are completely unrelated. Im not surprised you dont understand that since you think NA engines "pull" while turbo engines "push".

I have no problem with people outright attacking the BMF design. In fact, the more sure they are and the more devastating their argument, the better. I can change the BMF design at any time and would gladly incorporate ideas that make sense. The current design is based on what works. High power 2.2/2.5's have big plenums and big runners. But what you are describing is generic fluff, and you are admitting that its not really compared to anything else but the BMF itself. Thats a complete dead end as far translating those things into something real. How much of a difference are we talking about? 1%? 10%? To an intake which is likely good for 600hp+? Who cares? Can you even prove that it would be an improvement? No. But we do know that bigger runners WORK. What you are saying are just buzz-words without any reference. The exact sort of thinking that I want to avoid at all costs in anything I make.

Exactly what does what you are saying boil down to as far as a BMF design change. Instead of the 6 degree taper with a 2 inch length, it would be changed to a 6 inch length from the port to the plenum? And how much of a difference would that make? The cost to do that would probably double the cost of the intake. You cant just do it because the buzz words sound nice. Youve got to have better evidence than that and there isnt any.

[cordes]

Does the BMF runner taper from the plenum to the head? If so, by how much? Sorry if I missed it.

Oh, and sorry about the toilet too. I can own up to that one.

[acannell]

Does the BMF runner taper from the plenum to the head? If so, by how much? Sorry if I missed it.

Oh, and sorry about the toilet too. I can own up to that one.

I have a toilet situation, and I finally got the valve for $7 from junkmart. How nice it will be when its finally fixed.

The runners are circular tubes. The head flange has a taper in it that funnels the runner circular cross section into the port. The "funnel" is about 6 degrees and about 1.8 inches long.


http://i242.photobucket.com/albums/ff197/acannell/20150117_160454_zpszs05mbpk.jpg (http://s242.photobucket.com/user/acannell/media/20150117_160454_zpszs05mbpk.jpg.html)

[5DIGITS]

I have a toilet situation, and I finally got the valve for $7 from junkmart. How nice it will be when its finally fixed.

The runners are circular tubes. The head flange has a taper in it that funnels the runner circular cross section into the port. The "funnel" is about 6 degrees and about 1.8 inches long.


http://i242.photobucket.com/albums/ff197/acannell/20150117_160454_zpszs05mbpk.jpg (http://s242.photobucket.com/user/acannell/media/20150117_160454_zpszs05mbpk.jpg.html)


This is good - now that the atmosphere is lightening up a bit... ;)

No one is criticizing this design while offering a few suggestions for adjustment.
These are good things offered in a welcome environment.

[5DIGITS]

12 inch long runners would put the plenum behind the firewall. The phrase "7 degree taper over 12 inches" doesnt really make sense anyways. The taper angle is the taper angle, independent of length. The BMF taper angle is about 6 degrees and the taper is about 1.8 inches long.

Toilets have nothing to do with engines. Water is not compressible. The physics are completely unrelated. Im not surprised you dont understand that since you think NA engines "pull" while turbo engines "push".

I have no problem with people outright attacking the BMF design. In fact, the more sure they are and the more devastating their argument, the better. I can change the BMF design at any time and would gladly incorporate ideas that make sense. The current design is based on what works. High power 2.2/2.5's have big plenums and big runners. But what you are describing is generic fluff, and you are admitting that its not really compared to anything else but the BMF itself. Thats a complete dead end as far translating those things into something real. How much of a difference are we talking about? 1%? 10%? To an intake which is likely good for 600hp+? Who cares? Can you even prove that it would be an improvement? No. But we do know that bigger runners WORK. What you are saying are just buzz-words without any reference. The exact sort of thinking that I want to avoid at all costs in anything I make.

Exactly what does what you are saying boil down to as far as a BMF design change. Instead of the 6 degree taper with a 2 inch length, it would be changed to a 6 inch length from the port to the plenum? And how much of a difference would that make? The cost to do that would probably double the cost of the intake. You cant just do it because the buzz words sound nice. Youve got to have better evidence than that and there isnt any.

In no way is anyone attacking your efforts in trying to create improved components for these cars - in previous posts your efforts were applauded.

The reference to a 7 degree taper was confusing, I agree.
Think of it like this, if you will.
If the taper you have built into the injector boss was extended from the port entrance to the plenum, it would be superior approach.
Although, the effort required to do so would elevate the cost and labor required to accomplish the task - not good.
Therefore, if a slight reduction in tube size is entertained then the taper at the injector boss would be less aggressive.
This can/would reduce any issues of undesired turbulence resulting from localized velocity increases.

Typed words lead to insinuated tone - receive respectfully.

[acannell]

In no way is anyone attacking your efforts in trying to create improved components for these cars - in previous posts your efforts were applauded.

The reference to a 7 degree taper was confusing, I agree.
Think of it like this, if you will.
If the taper you have built into the injector boss was extended from the port entrance to the plenum, it would be superior approach.
Although, the effort required to do so would elevate the cost and labor required to accomplish the task - not good.
Therefore, if a slight reduction in tube size is entertained then the taper at the injector boss would be less aggressive.
This can/would reduce any issues of undesired turbulence resulting from localized velocity increases.

Typed words lead to insinuated tone - receive respectfully.

I made it clear I am looking for criticism. This title of this thread is clearly inviting doubt and complaints. You're trying to make it seem as if I'm disagreeing with you simply because you have some criticism. Not true. The idea I'm looking for applause or constant approval of my efforts is really gross. Please stop. If you are going to respond to my ideas then I have a right to respond to yours, and that does not mean what I'm saying is hurt feelings. I simply think what you're saying isn't realistic and has no meaningful benefit, regardless of how much it costs to do or not.

Alot of your basic ideas have something in common:

-Turbo's "push" while NA "pulls"
-Toilets and engines are related
-Water and air flow are related
-7 degree tapers over 12 inches

Notice a pattern here? None of them make sense. The things you are saying all are called "hype". If I ever had to justify why I designed something and handed the pretentious paragraph you wrote to somebody, I would be ashamed to be taking money for it. Most of the automotive industry operates on this principle. No reference. No scale. You still haven't said how much is to be gained (or lost). Thats because its unknowable, and almost certainly in the single digit percentages either way. What you are suggesting has influence in the upper teeny percentage of effect, either good or bad, on an intake that is probably bigger than any other that has been installed on a TD/TM. If someone else was selling a BMF clone and mine had this tiny change and theirs didn't, the best I could honestly say as far as a sales pitch would be "Its a wild a%% guess as to how different they are.". Thats because its just hype. Hype burns cash. Making a part like this is about dominant effects.

[acannell]

If anything on this intake needs to be bigger IMO it's the neck from the TB to the plenum, and that's to smooth and SLOW the air down into the plenum.

Check out a modification Shadow did. I like it. But not likely it would appear on a production BMF. I like that it moves the throttle body elbow connection to the plenum away from the runners. It also adds an ENORMOUS amount of volume. Probably pushes effective plenum volume up to 5+ litres, not including the rest of the intake.

http://i242.photobucket.com/albums/ff197/acannell/IMG_2777_zps8bdf709a.jpg (http://s242.photobucket.com/user/acannell/media/IMG_2777_zps8bdf709a.jpg.html)

[5DIGITS]

I made it clear I am looking for criticism. This title of this thread is clearly inviting doubt and complaints. You're trying to make it seem as if I'm disagreeing with you simply because you have some criticism. Not true. The idea I'm looking for applause or constant approval of my efforts is really gross. Please stop. If you are going to respond to my ideas then I have a right to respond to yours, and that does not mean what I'm saying is hurt feelings. I simply think what you're saying isn't realistic and has no meaningful benefit, regardless of how much it costs to do or not.

Alot of your basic ideas have something in common:

-Turbo's "push" while NA "pulls"
-Toilets and engines are related
-Water and air flow are related
-7 degree tapers over 12 inches

Notice a pattern here? None of them make sense. The things you are saying all are called "hype". If I ever had to justify why I designed something and handed the pretentious paragraph you wrote to somebody, I would be ashamed to be taking money for it. Most of the automotive industry operates on this principle. No reference. No scale. You still haven't said how much is to be gained (or lost). Thats because its unknowable, and almost certainly in the single digit percentages either way. What you are suggesting has influence in the upper teeny percentage of effect, either good or bad, on an intake that is probably bigger than any other that has been installed on a TD/TM. If someone else was selling a BMF clone and mine had this tiny change and theirs didn't, the best I could honestly say as far as a sales pitch would be "Its a wild a%% guess as to how different they are.". Thats because its just hype. Hype burns cash. Making a part like this is about dominant effects.


-Turbo's "push" while NA "pulls"
An NA engine does not draw the air into the combustion chamber, at atmospheric pressure, during the downward stroke while forced induction doesn't accomplish it's task by design?
Please explain

-Toilets and engines are related
-Water and air flow are related
In many cases, fluid is used during the porting of heads to visually characterize port behavior.
You're not aware of this while metaphorically making a humorous reference.

-7 degree tapers over 12 inches
Explained in a subsequent post as extending the current taper in the manifold

The literal tension and unnecessary reply attacks during constructive suggestions appears somewhat self contradictory while welcoming criticism.

Genuinely, It's a nice piece and is a cost effective replacement for those seeking increases while having a bit a room for maturity.

[Vigo]

I've been active around here since a few months after the forum came into existence, so here's some unsolicited context from someone who's been here a long time:

A. Antagonizing 5digits is barking up the wrong tree. There are a number of people on this forum we cant afford to run off by being jerks to them and he is one.
B. I understand there is a desire to keep the momentum of the thread up but i also think we should not just gloss over or ignore the stuff we don't want to hear because then we spend pages just retreading the same ideas trying to pound them into each other and to me that makes whatever we're doing less useful as a concise reference for other people to refer back to. Maybe i am wrong about resonance tuning (although that sounds like a subject for a whole other long-winded thread) and i'm open to being shown that it is simple enough to be practical for a hobbyist to implement. I hope everyone else is actually willing to be proven wrong or we are just yapping at each other for no reason.

I am happy to consider this idea of dual 2.5" pipes around the fuel tank, or how coilover springs make room for 4" pipe. These are simple ideas that could lead somewhere and the only hangups are the availability of app-specific pieces that Acannell is always looking for ideas for. On the other hand, i think talking endlessly about large throttle bodies is not useful unless and until we ALL understand that they have different requirements on boosted small displacement engines vs large naturally aspirated ones. So if we want to talk about something like that we should focus on getting the differences hammered out quickly so we can talk about merit in OUR application. I also think the idea of having the throttle body neck 'grow' through its turn to slow flow into the plenum is a great topic for discussion. The difficulty in building/sourcing pipes that increase in radius during a tight 90 degree turn is ALSO the one thing keeping us from building a truly beautiful turbine discharge piece that Acannell is also interested in making. So i think some ideas are gold mines and some are duds and hope we can latch onto one or two things and actually develop the ideas.

[cordes]

How far off from 7* over the length of the runner is the current BMF intake?

On Vigo's point, does anyone have a good idea for a way to make a better transition from the TB to the plenum? I've always thought that there must be a good way to do that, but haven't come up with anything easier than CF and that's not easy at all.

[acannell]

-Turbo's "push" while NA "pulls"
An NA engine does not draw the air into the combustion chamber during the downward stroke while forced induction doesn't accomplish it's task by design?
Please explain


There is pressure in the plenum whether a turbo is there or not. In an NA engine its thanks to gravity generating 1 bar of pressure in the atmosphere at sea level on this planet. In a turbo its thanks to a turbine powering a compressor wheel and creating pressure above and beyond 1 bar. Its just a matter of magnitude. When the volume the gas is trapped in increases, the energy in the gas causes it to expand into the new volume. That same effect fills the cylinder regardless of how high the pressure is.

[acannell]

How far off from 7* over the length of the runner is the current BMF intake?

On Vigo's point, does anyone have a good idea for a way to make a better transition from the TB to the plenum? I've always thought that there must be a good way to do that, but haven't come up with anything easier than CF and that's not easy at all.

You can do it with a hemisphere like Shadow did, or I could probably think up some other way to do it.

The tricky part is the pump side. Theres not much room there to copy what you do on the TB side.

But if we say we only want to focus on the TB side, it might be possible to just to CNC cut a strip of sheet metal the perfect shape so that when its rolled up end to end it forms a little cone. There is extra labor for welding (not insignificant, thats a weird thing to weld up since its free to move about in many dimensions), and machining, but its feasible. Would I like that modification on my own BMF? Yes.

I think in this particular case (a smoother TB elbow transition to plenum) that its a matter of picking when it makes sense to do it on a production BMF. Kind of hard to tell. Are we already well beyond what even the people who bought the BMF can flow through it? I dunno. Sort of the same with thing why it has a 2.5" elbow instead of 3". When do certain changes start to make sense?

The BMF head is about a 6 degree taper. This shows what it would look like if that taper were continued all the way to the plenum.

http://i242.photobucket.com/albums/ff197/acannell/untitled_zpsf89578ef.jpg (http://s242.photobucket.com/user/acannell/media/untitled_zpsf89578ef.jpg.html)

[acannell]

I've been active around here since a few months after the forum came into existence, so here's some unsolicited context from someone who's been here a long time:

A. Antagonizing 5digits is barking up the wrong tree. There are a number of people on this forum we cant afford to run off by being jerks to them and he is one.
B. I understand there is a desire to keep the momentum of the thread up but i also think we should not just gloss over or ignore the stuff we don't want to hear because then we spend pages just retreading the same ideas trying to pound them into each other and to me that makes whatever we're doing less useful as a concise reference for other people to refer back to. Maybe i am wrong about resonance tuning (although that sounds like a subject for a whole other long-winded thread) and i'm open to being shown that it is simple enough to be practical for a hobbyist to implement. I hope everyone else is actually willing to be proven wrong or we are just yapping at each other for no reason.

I am happy to consider this idea of dual 2.5" pipes around the fuel tank, or how coilover springs make room for 4" pipe. These are simple ideas that could lead somewhere and the only hangups are the availability of app-specific pieces that Acannell is always looking for ideas for. On the other hand, i think talking endlessly about large throttle bodies is not useful unless and until we ALL understand that they have different requirements on boosted small displacement engines vs large naturally aspirated ones. So if we want to talk about something like that we should focus on getting the differences hammered out quickly so we can talk about merit in OUR application. I also think the idea of having the throttle body neck 'grow' through its turn to slow flow into the plenum is a great topic for discussion. The difficulty in building/sourcing pipes that increase in radius during a tight 90 degree turn is ALSO the one thing keeping us from building a truly beautiful turbine discharge piece that Acannell is also interested in making. So i think some ideas are gold mines and some are duds and hope we can latch onto one or two things and actually develop the ideas.

I haven't glossed over anything or tried to change the subject. If you want to see glossing over, look at the generalities 5DIGITS uses. If you cant see hype and fluff there then I don't know what to tell you. I have a right to respond to what hes saying and I disagree with it. If people run away from the forum because they don't like their ideas challenged, thats not my fault.

If it sounds like I'm being a jerk to him, I would say that pointing out major problems with his ideas about airflow, like how a cylinder fills with air in NA verus turbo, is totally relevant to the discussion. If you think that can be ignored then thats the real glossing over. We need to call whats an educated guess, whats totally made up, and whats proven fact as such. Or the discussion really does become pointless and goes nowhere and I wont waste my time being a part of it.

If hype rules the day, the only products based on hype will sell, and I'm not interested in making hype based products.

[5DIGITS]

If you want to see glossing over, look at the generalities 5DIGITS uses.

Validated

[Shadow]

-Turbo's "push" while NA "pulls"
An NA engine does not draw the air into the combustion chamber, at atmospheric pressure, during the downward stroke while forced induction doesn't accomplish it's task by design?
Please explain

-Toilets and engines are related
-Water and air flow are related
In many cases, fluid is used during the porting of heads to visually characterize port behavior.
You're not aware of this while metaphorically making a humorous reference.

-7 degree tapers over 12 inches
Explained in a subsequent post as extending the current taper in the manifold

The literal tension and unnecessary reply attacks during constructive suggestions appears somewhat self contradictory while welcoming criticism.

Genuinely, It's a nice piece and is a cost effective replacement for those seeking increases while having a bit a room for maturity.

THIS^^^^^

Since it was Not practical ($ and labor constraints) to build a proper runner with proper tapper (I went through this with the boys in the Very early stages of the BMF) My objective became moving in the direction of what I believed would be the Best compromise to the runner in order to achieve a Great flowing mani that could work across a broad range of builds.

Lets keep in mind that Asa's "out of the box" version is Only the beginning. The changes I made to it already Expand on that good platform and there is a Little more room to grow as well;)


I've been active around here since a few months after the forum came into existence, so here's some unsolicited context from someone who's been here a long time:

A. Antagonizing 5digits is barking up the wrong tree. There are a number of people on this forum we cant afford to run off by being jerks to them and he is one.
B. I understand there is a desire to keep the momentum of the thread up but i also think we should not just gloss over or ignore the stuff we don't want to hear because then we spend pages just retreading the same ideas trying to pound them into each other and to me that makes whatever we're doing less useful as a concise reference for other people to refer back to. Maybe i am wrong about resonance tuning (although that sounds like a subject for a whole other long-winded thread) and i'm open to being shown that it is simple enough to be practical for a hobbyist to implement. I hope everyone else is actually willing to be proven wrong or we are just yapping at each other for no reason.

I am happy to consider this idea of dual 2.5" pipes around the fuel tank, or how coilover springs make room for 4" pipe. These are simple ideas that could lead somewhere and the only hangups are the availability of app-specific pieces that Acannell is always looking for ideas for. On the other hand, i think talking endlessly about large throttle bodies is not useful unless and until we ALL understand that they have different requirements on boosted small displacement engines vs large naturally aspirated ones. So if we want to talk about something like that we should focus on getting the differences hammered out quickly so we can talk about merit in OUR application. I also think the idea of having the throttle body neck 'grow' through its turn to slow flow into the plenum is a great topic for discussion. The difficulty in building/sourcing pipes that increase in radius during a tight 90 degree turn is ALSO the one thing keeping us from building a truly beautiful turbine discharge piece that Acannell is also interested in making. So i think some ideas are gold mines and some are duds and hope we can latch onto one or two things and actually develop the ideas.

Well said! I think that threads and discussions in general have come a Long way in just the last few months on here. (lets face it, I for one, wasn't posting much and for good reason)

We Are maturing, and that process Needs to be nurtured. Emotion has Zero to do with searching out a Truth that "Fits" the objective. So lets keep it Open and Friendly! No need to feel like you're backed into a corner, just because someone has a different perspective on things.:thumb:

[Shadow]

Therefore, if a slight reduction in tube size is entertained then the taper at the injector boss would be less aggressive.
This can/would reduce any issues of undesired turbulence resulting from localized velocity increases.

When I read this it makes me think that you're missing the point of this intake. IF the cross section of the runners Decreases, then the intake is Diminished to a "lesser" piece and the ability to easily upgrade it becomes diminished as well.

eg. A 12" runner with 7" taper would have an entrance cross section of around 2" in order to work to the third harmonic on a High HP 8v like ours. (8000rpm)

IF you study what IS the BMF runner, you will notice that the 1.75" cross section is a compromise of that "ideal" runner. It retains the proper amount of cross section to flow the volume to the head and because of it's decreased length, it gets away with it.

By opening up the top of the runner and bellmouthing it, you get a slightly increased "feed", add to that tapering the lower runner to the head and you have a straight pipe that actually "acts" a lot like a tapered one, but Without the Extreme cost that would be associated.

Now, the Fact that this design will work with lower (300HP) applications "as is" would be the reason the head flange was left to the size it is.

On an application like the Charger, for instance, the lower inj boss would be ported Larger, because the head entrance is Larger. This would only Further the "Ideal" taper to the valve seat. Add even More to that, what I've done to the upper runner, adding the slight curve and you end up lengthening the runner by another inch while at the Same time, Increasing the feed point even More ;)

So, is the design Perfect for Every application "as is"? NO, and it was Never meant to be. It is simply the BEST and most affordable intake that IS available for our applications and there is Nothing that wasn't considered in its making.

I think the biggest problem here is that you came to the party Late my friend. ALL of your Q's would have been answered in the original BMF thread ;)

[acannell]

For those desiring to ponder the perfect runner, read from post #70 through #94 in the original intake design thread and you can get an idea how the decision was made to go with the existing BMF design and what the factors are that need to be considered:

http://www.turbododge.com/forums/f321/f329/393531-custom-tubular-intake-manifold-planning-5.html#post2701057

Basically it comes down to a dance between several fitment and machinability issues, and the desire to make the runner as big diameter as possible within those limits.

If the runner ID has any sort of optimum or near optimum tuning frequency, resonance, length, or diameter, its just luck. Or its not luck if you just consider the goal of "bigger ID" as enough of a plan to end up there and call it intentional.

Changing the head flange is extremely undesirable because of how well it balances all those factors. There is VERY little wiggle room and the price for wiggling is extremely high. If you want a different runner, whether it be tapered or funneled, I would recommend starting your thinking at the end of the head flange where it currently meets the runner tube. Open up from there into a huge funnel or make your bend somewhere past there.

Its not impossible that there could be some cost effective way to make changes like that. But I personally wouldn't invest design time in it unless it was clearly a HUGE change. I.e. something like Popes idea from 5/2013:

http://www.turbododge.com/forums/f321/f329/393531-custom-tubular-intake-manifold-planning-6.html#post2701873

http://www.turbododge.com/forums/attachments/development-lounge/66033d1367424179-custom-tubular-intake-manifold-planning-drawing1-model.jpg

Unless its something that radical then I think its too small of a change for me to work on. There are bigger fish to fry and more lower hanging fruit to get power out of IMO.

[GLHNSLHT2]

Ugh, TM is on the fritz again. Reply with quote buttons aren't working right

Anyway, ROB, are you saying that the BMF was not machined to gasket dimensions at the head? I'm hoping it was so it matches my ported head. I'd really hate to get rid of the machining with a die grinder.

If it is machined to gasket are you saying that the Charger is ported larger than the gasket?

[acannell]

Ugh, TM is on the fritz again. Reply with quote buttons aren't working right

Anyway, ROB, are you saying that the BMF was not machined to gasket dimensions at the head? I'm hoping it was so it matches my ported head. I'd really hate to get rid of the machining with a die grinder.

If it is machined to gasket are you saying that the Charger is ported larger than the gasket?

The BMF head flange port is gasket sized. At least on the top and sides. Its about 1/16" larger than the stock swirl/G head port (not gasket, but actual head port) on the bottom.

http://i242.photobucket.com/albums/ff197/acannell/20150118_115250_zpspjnn1ekv.jpg (http://s242.photobucket.com/user/acannell/media/20150118_115250_zpspjnn1ekv.jpg.html)

[Shadow]

Ugh, TM is on the fritz again. Reply with quote buttons aren't working right

Anyway, ROB, are you saying that the BMF was not machined to gasket dimensions at the head? I'm hoping it was so it matches my ported head. I'd really hate to get rid of the machining with a die grinder.

If it is machined to gasket are you saying that the Charger is ported larger than the gasket?

Asa has already given the answer, but to be specific to your Q, Yes, the Charger opening at the head is Slightly Larger than gasket size, so I would need to do a little "massaging" on the inj bore flanges to mate it up.

The out of the box design IS gasket size and matches up nicely with Most well ported heads. I think you will be fine :)

These are all good Q's though, as "old school" thinking was that the opening Should remain stock size and you Should be looking for the Greatest Velocity through the port.

I have Never agreed with this criteria and have always believe that all you need it the greatest differential Right at the Valve, when it opens!

So IF your head porter didn't do his job Right and Taper the head ports properly, then you have some work to do. Not to the BMF, but to the Head!

The BMF puts the greatest volume flow right behind the inj bore (where the factory one OR two piece is a Total Choke point) and then moves it through a tapered transition that Should put the greatest Velocity right AT the valve opening! ;)

So to clarify, the valve opening should Not be the same as the head port opening, it should be Smaller. (tapered)

[5DIGITS]

How far off from 7* over the length of the runner is the current BMF intake?

On Vigo's point, does anyone have a good idea for a way to make a better transition from the TB to the plenum?
I've always thought that there must be a good way to do that, but haven't come up with anything easier than CF and that's not easy at all.

Hi Cordes.

Because air much like water does not like to turn, widening the short side (the 'D' port) will improve flow.
This was incorporated on the 8V head during its revision in the early eighties to help overall flow while keeping the air on the floor during the tight turn into the bowl.
This approach was later incorporated into the intake manifolds on the Shelby HH GLHS to improve runner flow and PT Cruiser turbo intake TB to plenum elbow to improve TB to plenum flow.


http://www.turbo-mopar.com/forums/attachment.php?attachmentid=52746&stc=1

http://www.turbo-mopar.com/forums/attachment.php?attachmentid=52747&stc=1

The HH intake design used runners that visually appear twisted.
This accomplished better plenum to runner flow and throughout the subsequent turn into the head.
The gradual runner taper in both cases increased volume and reduced short side turbulence for improved overall flow.
Specific to the PT Cruiser TB-to-elbow transition is the same flat short side floor suggested earlier in the thread which literally saved the intake from the lethargic flow of its prototype predecessor.

Hope this helps.

[5DIGITS]

THIS^^^^^

Since it was Not practical ($ and labor constraints) to build a proper runner with proper tapper (I went through this with the boys in the Very early stages of the BMF) My objective became moving in the direction of what I believed would be the Best compromise to the runner in order to achieve a Great flowing mani that could work across a broad range of builds.

Lets keep in mind that Asa's "out of the box" version is Only the beginning. The changes I made to it already Expand on that good platform and there is a Little more room to grow as well;)



Well said! I think that threads and discussions in general have come a Long way in just the last few months on here. (lets face it, I for one, wasn't posting much and for good reason)

We Are maturing, and that process Needs to be nurtured. Emotion has Zero to do with searching out a Truth that "Fits" the objective. So lets keep it Open and Friendly! No need to feel like you're backed into a corner, just because someone has a different perspective on things.:thumb:

Rob this was very well put, coincides with previous points and related "kudos".
If budget wasn't a concern, an effort could be placed in various areas and previous items are addressed while considering this.
While I hope that no one feels cornered while simply discussing technical issues, we're here to share, learn and enjoy.

Again, well said.

[5DIGITS]

When I read this it makes me think that you're missing the point of this intake.
IF the cross section of the runners Decreases, then the intake is Diminished to a "lesser" piece and the ability to easily upgrade it becomes diminished as well.
eg. A 12" runner with 7" taper would have an entrance cross section of around 2" in order to work to the third harmonic on a High HP 8v like ours. (8000rpm)

IF you study what IS the BMF runner, you will notice that the 1.75" cross section is a compromise of that "ideal" runner.
It retains the proper amount of cross section to flow the volume to the head and because of it's decreased length, it gets away with it.

By opening up the top of the runner and bellmouthing it, you get a slightly increased "feed", add to that tapering the lower runner to the head and you have a straight pipe that actually "acts" a lot like a tapered one, but Without the Extreme cost that would be associated.

Now, the Fact that this design will work with lower (300HP) applications "as is" would be the reason the head flange was left to the size it is.

On an application like the Charger, for instance, the lower inj boss would be ported Larger, because the head entrance is Larger. This would only Further the "Ideal" taper to the valve seat. Add even More to that, what I've done to the upper runner, adding the slight curve and you end up lengthening the runner by another inch while at the Same time, Increasing the feed point even More ;)

So, is the design Perfect for Every application "as is"? NO, and it was Never meant to be. It is simply the BEST and most affordable intake that IS available for our applications and there is Nothing that wasn't considered in its making.

I think the biggest problem here is that you came to the party Late my friend. ALL of your Q's would have been answered in the original BMF thread ;)

Bell-mouthing, the attempted tapered runner, head porting to extend the injector boss taper, etc.. great points that helped summarize upstream considerations and clarify - it's appreciated.
With so many members and posts on the forum, there still may be others yet to arrive - glad to be here :thumb:

[cordes]

How big is the plenum on that HH intake? Does what appears to be a very long runner help to make up for the lack of plenum volume if there was one? I've always thought that the HH intake looked pretty sweet.

[GLHNSLHT2]

5digits, Since you mentioned the neck on the PT manifold, does this help or hurt flow????

http://i42.photobucket.com/albums/e301/thebest4/SRT-4/IMG_2046_zps1bb525f8.jpg

[85boostbox]

All these people in here talking about runner length but I only count 2 actually touching on what runner length does. I touched on it as well did Shadow a few posts back. Runner length will effect harmonics of the intake and what happens with the shockwaves of the air when the valve closes. Thats it. The only reason it moves the power band up or down is from the turbulence of the air coming back. It has been figured out that the best harmonic for our motors is the third harmonic. That gives the best results in what RPM our motors work in. Unless you have a all out build and is strictly for race, but even then.

As far as taper and angle going into the head, you want the easiest transition going into the head. We all have touched base with that and agree.

Now, Going from throttle body to plenum is important. The biggest mistake that I see the BMF struggling in with this is the transiton. The way that I have built intakes, with a elbow or no elbow, is to have angled going into the plenum. That way there is no starvation of flow of air going into any of the cylinders. Best example I can come up with is when people have cut the elbows off of the 2 piece uppers and have staved air for cylinder one. DJ in his build thread put up graphs of his intake into a flow program that showed the same thing. That is the reason why he designed his intake the way he did. I'll see if I can pull up and load some of the graphs of some of the intakes that I have built and designed from solidworks to give you guys a better understanding of it.

[acannell]

Now, Going from throttle body to plenum is important. The biggest mistake that I see the BMF struggling in with this is the transiton.

The absence of a smooth transition from the elbow to the plenum volume is not something that was overlooked or a mistake. It was an intentional design decision based on weighing all the factors.

Perspective is important here. Imagine if the BMF was scaled up to be 5 times how big it is now in every dimension, but was otherwise exactly the same. The same flat transition from elbow to plenum volume. There would be no concern of starving anything of air or equalizing air, because the volumes are so large, they dwarf the effects of whatever the geometry of the intake is. Thats why comparing the intake to itself needs to be done very carefully or you chase your tail around without actually comparing it so a fixed reference thats relevant to the engine and power level thats being made.

Specifically what I am saying is, the volume of the BMF plenum is so enormous, and the throttle body elbow so enormous, that there is no significant effect, in my opinion, from having a flat wall there.

This is an area that would require some testing to prove. But I would say that if you can't admit that at some point, geometries become irrelevant as volumes and diameters become large enough, then you aren't being completely rational in analyzing how something like this is designed. You can test your thinking by asking "How big does it have to be before a flat wall at the ends of the plenum make no difference". If your answer is "infinity" then you aren't being rational. There is a point where it stops mattering. I think that point is reached when the TB elbow is nearly the size of a 2 piece plenum and is large even compared to the BMF plenum. There isnt that much of a drastic change in anything going on. There is tons of space for the volume to feed things equally.

Another test would be "How big does the throttle body elbow diameter need to be before a transition to the plenum makes no difference?". If you say "plenum sized" then again, I dont think you are being rational. Surely some size much smaller than the plenum ends up feeding the runners as well as they can be fed from an intake with the throttle on one end.

[85boostbox]

I will agree with you on the plenum size will have an effevt on that transition. But when you really start pushing efficiency with an intake, those little things will add up. Not much, but still will. Now the plenum size being more than the actual displacment of the engine, yes for everyday people will not have that much of a big effect on it. And I think the only time it would is when you really start pushing the bar on what an intake will handle, and how much the motor is really consuming. Then it all goes into volumetric efficiency of the engine.

[acannell]

I will agree with you on the plenum size will have an effevt on that transition. But when you really start pushing efficiency with an intake, those little things will add up. Not much, but still will. Now the plenum size being more than the actual displacment of the engine, yes for everyday people will not have that much of a big effect on it. And I think the only time it would is when you really start pushing the bar on what an intake will handle, and how much the motor is really consuming. Then it all goes into volumetric efficiency of the engine.

I am the first to admit there is very little data on the BMF so far. Moparzrule has some seat of the pants data and I think an aborted track run. I have data from my very weird Daytona build at low power. But thats going to change. There are going to be more than 20 BMF's out there this year and people are putting them on HOT builds. We will eventually get data. Also, I am re-building my own Daytona to be a high power rig so I can properly evaluate and tune for the BMF and other new "devices" that go along with an intake that big. :eyebrows:

As far as pushing efficiency on the BMF, I would really enjoy seeing someone do that. Its alot of volume and alot of cross sectional area, I'm pretty sure I wont touch it with my super 46 turbo. I think maybe signsoflife22, Shadow, and others putting the holset on and going for broke might have a chance though.

[85boostbox]

I would be willing. But I am going the 2.4 route:eyebrows:

[5DIGITS]

How big is the plenum on that HH intake? Does what appears to be a very long runner help to make up for the lack of plenum volume if there was one? I've always thought that the HH intake looked pretty sweet.

The HH GLHS plenum was actually too small for the application based on the demand of the 16v head and was pretty close to a two-piece plenum size.
This was largely due to packaging constraints and it would have benefited from growth.
Yes - increased runner size can make up for short-comings within the plenum size but at the cost of runner pulse tuning/strength.. it hurts low end port filling.

[acannell]

I would be willing. But I am going the 2.4 route:eyebrows:

Hmm...out of curiousity what does the 2.4 intake mounting method look like? How much of a change would there need to be to adapt an intake made for the 2.2/2.5 to it?

[black86glhs]

I believe what you are going to find that the little bit of starvation or turbulence that might happen will not effect anything under the 400 hp mark. Even if it shows up for those pushing things(500-600 hp), is it really going to be that bad compared to what is out there? I seriously doubt it.

[85boostbox]

Hmm...out of curiousity what does the 2.4 intake mounting method look like? How much of a change would there need to be to adapt an intake made for the 2.2/2.5 to it?


The flanging is completely different, also is the port entrance. After that I am not really sure about spacing. I would imagine that would be different due to having intake manfold and exhaust manifold on opposite sides. I can measure center to center for you tomorrow though to give you a better idea.

[acannell]

I believe what you are going to find that the little bit of starvation or turbulence that might happen will not effect anything under the 400 hp mark. Even if it shows up for those pushing things(500-600 hp), is it really going to be that bad compared to what is out there? I seriously doubt it.

That pretty much sums up what I am trying to get across for most of the suggested changes so far. I just try to back it up with more hand waving.

And I would like to hazard the opinion that not only will it not be that bad compared to what is out there, but it will be much MUCH better :)

[5DIGITS]

5digits, Since you mentioned the neck on the PT manifold, does this help or hurt flow????

http://i42.photobucket.com/albums/e301/thebest4/SRT-4/IMG_2046_zps1bb525f8.jpg

This hurts flow and is close to the first iteration of the intake design.
Having watched the painful process of Ed (flow room tech) squeeze everything possible from that design, I came to appreciate what he accomplished.
What the welded elbow did gain is transition from the TB mounting plate, from what I can tell from the photo.
Although remembering how it acted on the flow bench, the elbow tube may not be the best approach and comes with a cost of flow.
Therefore, I suggest enlarging the elbow to gain volume for a near non-existent plenum while applying any effort afforded to widen the short side of the neck.

[85boostbox]

I believe what you are going to find that the little bit of starvation or turbulence that might happen will not effect anything under the 400 hp mark. Even if it shows up for those pushing things(500-600 hp), is it really going to be that bad compared to what is out there? I seriously doubt it.


You're probably right, but until there is some more real world testing, you will never know. The downside that I see right off the bat is making a "smaller" turbo working harder to fill the plenum size. I could really see a smaller turbo running out of breathe way before the 400+ range with this intake. So real world people might be needing to upgrade there turbo before a well ported 2 piece. Not so much bad, but as stated until we see more real world numbers as testing, it is all speculation.

[85boostbox]

This hurts flow and is close to the first iteration of the intake design.
Having watched the painful process of Ed (flow room tech) squeeze everything possible from that design, I came to appreciate what he accomplished.
What the welded elbow did gain is transition from the TB mounting plate, from what I can tell from the photo.
Although remembering how it acted on the flow bench, the elbow tube may not be the best approach and comes with a cost of flow.
Therefore, I suggest enlarging the elbow to gain volume for a near non-existent plenum while applying any effort afforded to widen the short side of the neck.


I would like to know how long those runners are on that intake total. I got in the area of 3.5 from flange to valve when coming up with an intake for my build. So would have to add that into the equation.

[5DIGITS]

I believe what you are going to find that the little bit of starvation or turbulence that might happen will not effect anything under the 400 hp mark. Even if it shows up for those pushing things(500-600 hp), is it really going to be that bad compared to what is out there? I seriously doubt it.

On the contrary, the higher HP/higher demanding flow engines will accentuate the issue due to increased velocity and the air leaving the port walls due to the isolated 1.8" 6 degree taper.
This, believe it or not, is where a smaller volume runner will excel due to its elimination of this constrained taper.

[black86glhs]

You're probably right, but until there is some more real world testing, you will never know. The downside that I see right off the bat is making a "smaller" turbo working harder to fill the plenum size. I could really see a smaller turbo running out of breathe way before the 400+ range with this intake. So real world people might be needing to upgrade there turbo before a well ported 2 piece. Not so much bad, but as stated until we see more real world numbers as testing, it is all speculation.You and I are in the same ball park. I just don't know if anyone here can actually do the testing needed. It is assumed that if a problem comes up, it is "A" causing it and it could be something else or a combo of things.
Not saying don't test, just wondering if there is a little bit of over-thinking going on. Maybe not necessarily over-thinking, but guys who want to be the one to find an issue that isn't really a big factor. That isn't a bad thing, necessarily. I know this will be misunderstood and a couple here will get butt hurt by it. Don't.

[acannell]

You're probably right, but until there is some more real world testing, you will never know. The downside that I see right off the bat is making a "smaller" turbo working harder to fill the plenum size. I could really see a smaller turbo running out of breathe way before the 400+ range with this intake. So real world people might be needing to upgrade there turbo before a well ported 2 piece. Not so much bad, but as stated until we see more real world numbers as testing, it is all speculation.

At 200hp the 2.5L is consuming around 300cfm of air, or about 5 cf per second. The entire volume of the BMF is 0.2cf. So the engine is consuming 25 times the volume of air in the BMF every second at only 200hp. At twice that power, 50 times. Static volumes like the intake tract, including intercoolers, plumbing, the intake itself, etc... are all really small compared to the amount of air the turbo has to move to power the engine. They take milliseconds to fill up.

[acannell]

Not saying don't test, just wondering if there is a little bit of over-thinking going on. Maybe not necessarily over-thinking, but guys who want to be the one to find an issue that isn't really a big factor. That isn't a bad thing, necessarily.

Well said.

[85boostbox]

At 200hp the 2.5L is consuming around 300cfm of air, or about 5 cf per second. The entire volume of the BMF is 0.2cf. So the engine is consuming 25 times the volume of air in the BMF every second at only 200hp. At twice that power, 50 times. Static volumes like the intake tract, including intercoolers, plumbing, the intake itself, etc... are all really small compared to the amount of air the turbo has to move to power the engine. They take milliseconds to fill up.

If that were the case then nobody would ever have to upgrade a turbo. Remember it is all about improving the overall efficiency of the engine. It may take milliseconds to fill back up, but when you start increasing the volumetric efficiency of an engine, other things have to increase as well.

[black86glhs]

On the contrary, the higher HP/higher demanding flow engines will accentuate the issue due to increased velocity and the air leaving the port walls due to the isolated 1.8" 6 degree taper.
This, believe it or not, is where a smaller volume runner will excel due to its elimination of this constrained taper.That is why I said I believe. Trust me, you understand this more than I do. I understand the basics in fluid mechanics and that is what limits me in this situation. I am not supporting anyone in particular in this argument. I guess my point is look at what we were working with(mainly stock intakes in my analogy) and look at this and some of the others. Not light years ahead of the 2 piece, but a damn good bit better.

Let's face it, we are all proud people who take pride in doing the things we do. I can't fault anyone for wanting to point out something nor can I say that it should be ignored because "we" didn't come up with it. I have been horrible for dismissing stuff because I didn't think of it. Took me a few years to learn that one because I'm a stubborn SOB....lol.

[85boostbox]

You and I are in the same ball park. I just don't know if anyone here can actually do the testing needed. It is assumed that if a problem comes up, it is "A" causing it and it could be something else or a combo of things.
Not saying don't test, just wondering if there is a little bit of over-thinking going on. Maybe not necessarily over-thinking, but guys who want to be the one to find an issue that isn't really a big factor. That isn't a bad thing, necessarily. I know this will be misunderstood and a couple here will get butt hurt by it. Don't.

No butt hurt here lol. I am all about intelligent conversations when it comes to cars. Very rare to ever full on get conversations like these. This is what makes this forum and these cars so special, and probably the reason why I will never leave is all the aftermarket that has come from regular car people and not big corporations.

[black86glhs]

No butt hurt here lol. I am all about intelligent conversations when it comes to cars. Very rare to ever full on get conversations like these. This is what makes this forum and these cars so special, and probably the reason why I will never leave is all the aftermarket that has come from regular car people and not big corporations.
The butt hurt comment was not directed at anyone in particular. It is just human nature that a couple people in a group this size will misunderstand or take it wrong. I have done it myself too many times in the past.
I agree, this type of discussion is good.

[acannell]

If that were the case then nobody would ever have to upgrade a turbo. Remember it is all about improving the overall efficiency of the engine. It may take milliseconds to fill back up, but when you start increasing the volumetric efficiency of an engine, other things have to increase as well.

The intake tract volume is tiny compared to the volume of air the engine is consuming. Increasing the VE of the engine would only make that difference even more pronounced. Turbos arent sized according to intake tract volume, they're sized to mass air flow into the engine. Look at a compressor map. Theres no "static volume" factor because the intake tract is inconsequential at airflows in the hundreds of CFM.

[black86glhs]

You're probably right, but until there is some more real world testing, you will never know. The downside that I see right off the bat is making a "smaller" turbo working harder to fill the plenum size. I could really see a smaller turbo running out of breathe way before the 400+ range with this intake. So real world people might be needing to upgrade there turbo before a well ported 2 piece. Not so much bad, but as stated until we see more real world numbers as testing, it is all speculation.I missed this earlier and I do wonder if you have a point. Is the BMF really needed for the stock or barely more than stock vehicle? Testing it is a good start. Asa, not trying to bad mouth the intake and not saying it doesn't improve a less potent setup, just it will be up to each one to decide if they want to spend the money for it. Thankfully, that is each persons right to do what they wish with their cash(in my case, I consult with the smarter person I am married to:amen:).

[acannell]

I missed this earlier and I do wonder if you have a point. Is the BMF really needed for the stock or barely more than stock vehicle? Testing it is a good start. Asa, not trying to bad mouth the intake and not saying it doesn't improve a less potent setup, just it will be up to each one to decide if they want to spend the money for it. Thankfully, that is each persons right to do what they wish with their cash(in my case, I consult with the smarter person I am married to:amen:).

I dont think the BMF makes sense for a stock vehicle. Nobody who has bought one so far is putting it on anything close to stock IIRC.

[Shadow]

On the contrary, the higher HP/higher demanding flow engines will accentuate the issue due to increased velocity and the air leaving the port walls due to the isolated 1.8" 6 degree taper.
This, believe it or not, is where a smaller volume runner will excel due to its elimination of this constrained taper.

I'm not sure why you see a 1.8" taper in the complete runner tract? There is No choke there because that tapered transition goes Right to the valve! ;) (or Should)


The butt hurt comment was not directed at anyone in particular. It is just human nature that a couple people in a group this size will misunderstand or take it wrong. I have done it myself too many times in the past.
I agree, this type of discussion is good.

Good on you Bro! I am in Full agreement with Everything you have brought to this conversation!!!!!:thumb:

[85boostbox]

The intake tract volume is tiny compared to the volume of air the engine is consuming. Increasing the VE of the engine would only make that difference even more pronounced. Turbos arent sized according to intake tract volume, they're sized to mass air flow into the engine. Look at a compressor map. Theres no "static volume" factor because the intake tract is inconsequential at airflows in the hundreds of CFM.

This is true, but you are missing the point of where I am going with it. The more space you put before the valve for the turbo to fill, is only going to make the turbo work harder to fill it up. Add on top of that the amounbt of air the engine is going to use, it all needs to be a balance in what is happening.

Think of it like this. Take a straw. Blow into it. Air feels pronounced and you can blow through it with more pressure. Now tape 10 straws. Blow through it. Same circumference, less pressure at the end due to more surface area and more straws to fill.

[85boostbox]

Where is Warren Stramer to jump into a good efficiency thread like this :thumb:

[black86glhs]

I dont think the BMF makes sense for a stock vehicle. Nobody who has bought one so far is putting it on anything close to stock IIRC.OK. That really isn't part of this. I didn't think so, but didn't want to say it and get flamed.
Back to the regularly scheduled program.

[acannell]

This is true, but you are missing the point of where I am going with it. The more space you put before the valve for the turbo to fill, is only going to make the turbo work harder to fill it up. Add on top of that the amounbt of air the engine is going to use, it all needs to be a balance in what is happening.

Think of it like this. Take a straw. Blow into it. Air feels pronounced and you can blow through it with more pressure. Now tape 10 straws. Blow through it. Same circumference, less pressure at the end due to more surface area and more straws to fill.

The straw analogy you described doesn't match up with this. What you are demonstrating there is decreased work required when cross sectional area goes up. The engine phenomenon we've been discussing is increased work required when volume goes up. So in that case you would compare a straw and say two straws, and measure how long it takes for the pressure to go up at the end of the pipe when you blow on it and connect a shop vac to the other end. All your effort will go into meeting the shop vac demand. The volume of the straws is so tiny compared to the demand you are supplying that it doesnt matter if you double them. You could add 10 straws and the work you need to supply would only increase single digits percentage. The shop vac dominates the work demand. You would have to start adding volumes on the order of the air flow rate to matter. So in our engine, something like 5 cubic feet, or 140 litres. That would add 1 second at 300cfm airflow.

This is one case where the math really can be done and its simple. There is no guessing here. The volume increase of the intake tract is tiny compared to the airflow. No subjective tests or analogies are required.

If youre goal is really efficiency, think about the gained efficiency of increasing intake plenum size, intercooler size, intake tract plumbing, etc.. yet all of which add to intake tract volume and the requirement for the turbo to "fill it up". What you aren't taking into account is the immense air moving capacity of a turbocharger on an automotive engine. The volume of an intake tract is microscopic compared to what the turbo is pumping out and the engine is consuming. Its not relevant. Hundreds of cfm for flow. Fraction of a cfm for volume. Whatever work the turbo is doing is dominated by engine consumption by an order of magnitude. I can't explain it any simpler than that.

[glhs875]

I would say to the ones concerned about using this BMF intake on a stockish combo, that if this intake actually increased the airflow to a level that the turbo being used could no longer keep up with the demand, then the boost would act similar to a stock SRT4 and would loose pressure in the higher R's! I like to use Wallace Racing calculators when designing something such as an intake or even when doing port work! Would I consider using the BMF intake? I would say yes if the math of the intake falls into working in the RPM range I am shooting for with my combo . Which for me would be 5500 to 8500 RPM as the main power band. And also if the side entry of the plenum does not cause flow differences from one cylinder to another. Once the boost hits, the engine in my combo never drops below 5500 to 6000rpm. So that RPM range (5500-8500) is what Iam using to pick or make parts for. For now anyway!

[Shadow]

Touching on the comments in regards to using the BMF on a "stockish" setup.................You Can't....................PERIOD!

The mating flanges do Not align with a stock head. Go a little further and realize that even some mid ported heads do not increase the size of the intake and exhaust port inlets/ outlets and you come to realize that the very least you would have to do is port match the head to the intake.

Soon as you do that amount of porting on the head it is no longer anything close to stockish. (might as well drop in a cam at that point and really see some gains ;))

[5DIGITS]

I would like to know how long those runners are on that intake total. I got in the area of 3.5 from flange to valve when coming up with an intake for my build. So would have to add that into the equation.

Hi there.
I didn't understand your question - lets take it offline to respect the thread.
Send me a PM.

[5DIGITS]

Touching on the comments in regards to using the BMF on a "stockish" setup.................You Can't....................PERIOD!

The mating flanges do Not align with a stock head. Go a little further and realize that even some mid ported heads do not increase the size of the intake and exhaust port inlets/ outlets and you come to realize that the very least you would have to do is port match the head to the intake.
Soon as you do that amount of porting on the head it is no longer anything close to stockish. (might as well drop in a cam at that point and really see some gains ;))

"Shadow"
I have information regarding some previous discussions within the thread and recent discussion with our air-flow modeling group.
I had tried to PM them but there seems to be an issue with that right now.
Once corrected, I will send.

[Shadow]

"Shadow"
I have information regarding some previous discussions within the thread and recent discussion with our air-flow modeling group.
I had tried to PM them but there seems to be an issue with that right now.
Once corrected, I will send.

Sounds good :thumb:

[OmniLuvr]

The downside that I see right off the bat is making a "smaller" turbo working harder to fill the plenum size. I could really see a smaller turbo running out of breathe way before the 400+ range with this intake


Turbos arent sized according to intake tract volume, they're sized to mass air flow into the engine

the only difference would be the amount of pressure (psi) needed to meet the tq/hp # of the previous intake setup. a small turbo will make 250 hp, the only difference will be the psi needed to make it, unless the flow path is so restricted that it needs such a high psi to reach the number that its out of its pressure map. it would be the same thing as people adding 3" intercooler tubes that are 4 feet long (at least) to reach a large front mount intercooler, only problem might be "lag" which so far usually isn't the case.

there is also plenty of meat in the inj bore to be ported out to fit a heavily ported head like warrens that would reduce the "taper" point. again, this is why I opted for the unwelded version so I can port the intake flange to my head to have a nice flow path...

[Shadow]

there is also plenty of meat in the inj bore to be ported out to fit a heavily ported head like warrens that would reduce the "taper" point. again, this is why I opted for the unwelded version so I can port the intake flange to my head to have a nice flow path...

I don't want to beat this like a dead horse, but remember, that Taper Should follow all the way to the Valve seat! So there is No choke flow through that taper, Only Acceleration Too the Valve opening!

So the BMF gets the volume + pressure Too the opening of that inj flange and then the taper does the rest! Larger the port opening to the head, more gradual the taper But Still accelerating Too the valve opening!

[Reaper1]

You do NOT want maximum flow velocity AT the valve seat. The port will hit choked flow and the turbulence will KILL flow in the low lift areas. Maximum velocity, and the port choke point should be BEFORE the valve. Typically right around the STR (short turn radius).

A long time ago I did a lot of figuring on what size the port needed to be at the STR and I think I got right around 1.8sqin. (maybe is was 1.65...can't remember and the info is LONG gone, I'd have to re-do it all). This would be for an "ideal" situation based on a certain amount of flow required fro a certain amount of power. So, one size does NOT fit all (please keep that in mind).

[OmniLuvr]

I don't want to beat this like a dead horse, but remember, that Taper Should follow all the way to the Valve seat! So there is No choke flow through that taper, Only Acceleration Too the Valve opening!


I was basically just stating that the "taper" (in quotes) could be modified to suit other individuals needs, the taper that is put into it should be fine for a gasket matched head port job, but can be opened up much more if needed to suit other peoples needs for (much) larger ports.

[thedon809]

To sum this all up, I think we can all agree that having the large runners with a more gradual taper would be ideal, but whether it is actually worth the added cost is the question. The only true way to find out if the taper in the BMF intake hurts or doesn't would be a direct comparison with another BMF that had smaller runners instead of the taper, or the same size runners with a more gradual taper.

[acannell]

Heres what continuing the taper to the plenum would look like. Additional cost, probably $150. The cost is because the runners would have to be made from scratch and there would be alot more welding. I dont see what the big deal is. Its barely any different.

http://i242.photobucket.com/albums/ff197/acannell/untitled_zpsf89578ef.jpg (http://s242.photobucket.com/user/acannell/media/untitled_zpsf89578ef.jpg.html)

[OmniLuvr]

I think the "problem" in question about taper is in the manifold flange itself, because it starts at (?) size and ends at gasket size within a certain distance. so either the runner would have to be a smaller inside diameter (which I wouldnt want) or the intake port in the head would have to be larger than gasket with the intake flange being ported to suit.

personally, I don't think any of that is a problem with the intake, I don't think there is any "problems" at all, just certain tweaks they may want to be done to suit other peoples needs, but the whole point of "this" intake was to flow a crap load of air at a reasonable price, I mean, you are literally "giving" them away... well at cost anyways... and maybe not even that...

[Vigo]

a small turbo will make 250 hp, the only difference will be the psi needed to make it

I think most of the power differences between two turbos which are both capable of flowing X are firstly the pumping losses on the exhaust side, and much less significantly, changes in oxygen content in the air charge @ x psi due to differences in temperature from compressor adiabatic efficiency.

I guess one of the issues with this thread is that 'people' are asking other 'people' to hand out the equivalent of a high dollar education for free through what would probably be literally hours of typing, or just back away from using simplified analogies at all. Different people are talking on different levels, and i think there is a difference between someone being wrong, and someone just not being willing to dedicate a huge charity effort towards writing something that is complex out in a long and detailed enough form that it will be irrefutable. The internet has its limitations. One person can't and won't confer the learnings of an entire career out through a few posts, especially to a guy who is prickly about how he receives info. :p

Regarding water vs air (vaguely), here is a question: Doesnt air flow between the turbo and the intake valves SLOW as boost increases? Greater pressure potentially means moving a larger mass at a lower speed. I have an inkling that the boost number is actually a reflection of the fact that the intake charge CANT maintain the same speed as mass flow through the system goes up. Obviously the acceleration into the cylinder when the intake valve is open will be higher, but i wonder if the air transitioning from the throttle body to the plenum isnt actually slower than 'stock' at high boost pressures and whether this makes that transition area more forgiving.

[black86glhs]

Rob, you are correct and I should have clarified "stockish" in my previous posts. Someone might have a ported head but not making major HP(like me). The intake will fit on it, but isn't really designed for something like that. That makes sense.

[acannell]

Rob, you are correct and I should have clarified "stockish" in my previous posts. Someone might have a ported head but not making major HP(like me). The intake will fit on it, but isn't really designed for something like that. That makes sense.

I didnt see any negative effects using it on my stock unported swirl head at stock boost levels. I saw minor improvements but I have alot of other things done to the car so I cant really attribute that to the BMF.

Its not so much that the BMF wont work on a stock engine, its just being wasted, thats all. Like buying forged pistons but keeping everything else stock.

Also, Im pretty sure that the stock intakes and the head dont line up either unport-matched, so whatever kind of mismatch you get with the BMF is probably not much different than a stock intake. Or probably doesn't matter that much anyway at stock power levels.

[black86glhs]

I didnt see any negative effects using it on my stock unported swirl head at stock boost levels. I saw minor improvements but I have alot of other things done to the car so I cant really attribute that to the BMF.

Its not so much that the BMF wont work on a stock engine, its just being wasted, thats all. Like buying forged pistons but keeping everything else stock.

Also, Im pretty sure that the stock intakes and the head dont line up either unport-matched, so whatever kind of mismatch you get with the BMF is probably not much different than a stock intake. Or probably doesn't matter that much anyway at stock power levels.Agreed. That is the translation of my post.:thumb:

[5DIGITS]

I don't want to beat this like a dead horse, but remember, that Taper Should follow all the way to the Valve seat!
So there is No choke flow through that taper, Only Acceleration Too the Valve opening!
So the BMF gets the volume + pressure Too the opening of that inj flange and then the taper does the rest!
Larger the port opening to the head, more gradual the taper But Still accelerating Too the valve opening!


You do NOT want maximum flow velocity AT the valve seat.
The port will hit choked flow and the turbulence will KILL flow in the low lift areas.
Maximum velocity, and the port choke point should be BEFORE the valve. Typically right around the STR (short turn radius).

Great point - you are not alone on this one.
It's agreed within and outside this forum that this a poor place to accelerate something that does like to turn.
Consider that the bowl area increases in volume to reduce velocity, aid in short side flow while targeting a uniform turn into the seat area.

You brought up a second point that's worth recognizing - low lift flow.
While many target the greatest CFM # at peak lift, it typically comes at the cost of low lift flow.
The game of area under the curve is certainly a better approach when porting a head and your point was well placed.

[Shadow]

I was basically just stating that the "taper" (in quotes) could be modified to suit other individuals needs, the taper that is put into it should be fine for a gasket matched head port job, but can be opened up much more if needed to suit other peoples needs for (much) larger ports.

My dead horse comment wasn't directed at you :) Just an opportunity to state something that I believed people were missing ;)


You do NOT want maximum flow velocity AT the valve seat. The port will hit choked flow and the turbulence will KILL flow in the low lift areas. Maximum velocity, and the port choke point should be BEFORE the valve. Typically right around the STR (short turn radius).

A long time ago I did a lot of figuring on what size the port needed to be at the STR and I think I got right around 1.8sqin. (maybe is was 1.65...can't remember and the info is LONG gone, I'd have to re-do it all). This would be for an "ideal" situation based on a certain amount of flow required fro a certain amount of power. So, one size does NOT fit all (please keep that in mind).

Yeah, this is where trying to explain things on the net becomes a lesson in futility! lol I was simply trying to get people to "see" the intake tract as a Whole. To Remove the "tunnel vision" of just seeing the 1.8" taper in the manifold.

I Didn't mean that the taper actually goes Right to the seat, as that would be impossible. (the factory valve throat is already too big! lol) This is where I Expect people to read between the lines and use some Common sense, but my bad for wording it Wrong.

So, the taper is going to continue past the head flange area, and reach right down to the throat. (how's that?)

[5DIGITS]

Yeah, this is where trying to explain things on the net becomes a lesson in futility! lol
I was simply trying to get people to "see" the intake tract as a Whole.
To Remove the "tunnel vision" of just seeing the 1.8" taper in the manifold.
I Didn't mean that the taper actually goes Right to the seat, as that would be impossible. (the factory valve throat is already too big! lol)
This is where I Expect people to read between the lines and use some Common sense, but my bad for wording it Wrong.
So, the taper is going to continue past the head flange area, and reach right down to the throat. (how's that?)

Certainly easier to understand.
Much like a valve to seat ratio is desired (the seat ID should support 85% of the valve OD - a slightly higher ratio will work depending on the surrounding port work), the bowl area should exceed the area of the upstream port area.
Great care should be considered during the porting process to insure that the port enlargement is not extended to the point just prior to the bowl area.
Generally speaking, the air requires a 3/16" - 1/4" (Even wider on high RPM/high boost applications) to realize a reduction of velocity before the short side turn - not at the turn.
If the port area is opened too far and too late in the port (too close to the turn) it will be identified as audible "sputtering or air spitting" during flow bench testing with flow numbers that will go flat, regardless of increased valve opening/lift.