ok port or pass the 2 piece or put money else where

[Mr overkill]

ok so im getting the last of my parts gathered up cliff is getting my trans soon as soon as we can come up with a day and all


rocksolid bottom end forged everything stage 5 cal fwp, stage 2 head, adj fuel reg, adj cam sprocket, tu header, tu 3" sw with a t3/4 stage 2 , 3 " full exhaust


thats the quick rundown


will it be really worth it to get the intake ported??? how much less boost will i need to compensate for the intake if do port it


also i dont want to skip it if thats gonna be the bottle neck also


plan on running 20 psi and if fuel isnt a problem then a few psi more

[Vigo]

i would say it would be worth it to port the lower half, and skip doing anything to the top half.. instead, concentrate that effort on making a bigger plenum to bolt onto your ported lower half.

[GLHNSLHT2]

might as well

[Mr overkill]

i dont want to go crazy making a custom intake already went overkill on everythig lolol

[turbovanman²]

Port the bottom portion as much as you can, try to keep the taper. You can also port match the lower to upper holes and there severly mismatched. Some say it will cause issues, but I don't believe anyone has noticed anything bad. Open up the TB to 52mm.

[Directconnection]

How much time do you have to sit on the intake thing?

I ask, because I started work on my 2-piece intake and just the lower half really picked up flow.

For example: the test head I bolted it to flowed 179cfm. I bolted on a stock 2-piece lower half and flow dropped to 150. Then, I swapped that out for the roughed out runner of my other 2-piece lower half and flow picked up to the tune of 166cfm. All on the same head. Now...16 cfm gain doesn't sound like a huge amount, but you need to look at it differently as I was not flowing the intake by itself. One should realize that I cut my flow losses from the lower section my MORE than half. I was very impressed with those results. 29cfm loss @ stock vs 13 cfm loss on the ported unit.

I have much more to do including the top half which should improve as well.

I hope to document all of this and use it in an SDAC newsletter and then post it up here with all detailed pics as well.

I may do a 2nd intake all the while and sell to make some $ to finance the rest of my car, but as it is, it looks like I will have 40 hours or so into this thing:) .

[cordes]

How much time do you have to sit on the intake thing?

I ask, because I started work on my 2-piece intake and just the lower half really picked up flow.

For example: the test head I bolted it to flowed 179cfm. I bolted on a stock 2-piece lower half and flow dropped to 150. Then, I swapped that out for the roughed out runner of my other 2-piece lower half and flow picked up to the tune of 166cfm. All on the same head. Now...16 cfm gain doesn't sound like a huge amount, but you need to look at it differently as I was not flowing the intake by itself. One should realize that I cut my flow losses from the lower section my MORE than half. I was very impressed with those results. 29cfm loss @ stock vs 13 cfm loss on the ported unit.

I have much more to do including the top half which should improve as well.

I hope to document all of this and use it in an SDAC newsletter and then post it up here with all detailed pics as well.

I may do a 2nd intake all the while and sell to make some $ to finance the rest of my car, but as it is, it looks like I will have 40 hours or so into this thing:) .

Very interesting. Thanks for posting actual numbers. I really appreciate it.

[boost geek]

This isn't intake related, but I also have that stage 5 cal, havent tried it yet, fwdp claims 18 psi, with fuel tables to 28 or so psi. Does that mean it has boost cut out at 18?
As for the intake, I dont have a 2 piece, but I wonder if they have a similar elbow restriction like the 1 piece. Where I used to ping at 15 on my ported runner, stock 1 piece, I now ping at about 7 psi on a 1 piece with a 3.3 elbow and 52 mm t.b.- this thing flows way more now...

[johnl]

Port the bottom portion as much as you can, try to keep the taper. You can also port match the lower to upper holes and there severly mismatched. Some say it will cause issues, but I don't believe anyone has noticed anything bad. Open up the TB to 52mm.

No numbers here. Can't match Steve on that part. Just a general principle.

Where an increase in port area (diameter) will increase capacity, it will also reduce port velocity. Some of that velocity loss can be offset with a shallow and smooth taper. An inside divider can be used to make sure of your rate of taper.

Coarse tooth half round and rat tail files are useful to flatten out the humps and bumbs that rotary files unavoidably (and even invisibly) leave - and to ensure your taper. You can put curves into the tips and bodies of your files so they wont gouge the outside curves and will conform to the inside curve of whatever part of whatever port you're working on.

To make your curved files, heat the part that you want to bend to a very dull red (almost invisible - do it in the dark) don't get it too hot and bend to taste. Adjust your flame so you heat the core of the file, not the surface, (do as little harm as possible to the teeth); done right, the teeth will remain plenty tough and sharp enough to cut aluminum.

After you rough the port with your rotary files, finish with the curved tip half round and rat tail files. You will be astonished to see the high spots and low spots left by your rotary file work.

[glhs875]

No numbers here. Can't match Steve on that part. Just a general principle.

Where an increase in port area (diameter) will increase capacity, it will also reduce port velocity. Some of that velocity loss can be offset with a shallow and smooth taper. An inside divider can be used to make sure of your rate of taper.



Velocity is important, is great for throttle response and torque, but high velocity can bite you in the upper R's if that's what your after. Air only likes to move so fast. A certain cross sectional area is needed to achieve a certain rpm level. Here's what I did to my 2 piece. The runners have been welded and opened up alot to match the ports on my head. It's still a work in progress. I'm going experiment with custom upper plenum volume and runner length eventually. The engine was making great power to 7200rpm with a stock T1 cam, and with more torque than I could ever use on the street.

[Directconnection]

With the ported runner bolted to the head, flow is VERY stable. Before, the vertical manometer which is what you set to for your test pressure used to fluctuate a tad above and below (only like 1/16" inch which translates to 1-2 cfm) with this runner, it stays dead where I put it and has different sound.

Velocity... NA vs Turbo I think are two entirely different principles. I plan to run up to the 3-bar limit which is stuffing 3 times the air it would normally ingest in NA form... which in my theory increases velocity to the point of when you need to ask yourself on a turboed application, when is there too much?

My opinion...

[turbovanman²]

Thats what I think Steve, N/A and Turbo are different as we know, I am no engineer but to me, boost changes everything and anything you can do to streamline it will help make more power on less boost. Thats why I think the intake tests between the one piece and 2 piece are flawed. We flow them and there virtually indentical but I believe if you tested them under boost, the 2 piece would be a clear winner due to the less bends the air has to travel.

[mo' parts]

i went from a mildly ported 1pc. to a slightly ported head and ported 2-piece, and OMG what a difference! i do not know if i'll ever do the 1pc. again.
if anything i will fab up one similar to a 2pc. but with much more volume in the plenum.

[johnl]

With the ported runner bolted to the head, flow is VERY stable. Before, the vertical manometer which is what you set to for your test pressure used to fluctuate a tad above and below (only like 1/16" inch which translates to 1-2 cfm) with this runner, it stays dead where I put it and has different sound.

Velocity... NA vs Turbo I think are two entirely different principles. I plan to run up to the 3-bar limit which is stuffing 3 times the air it would normally ingest in NA form... which in my theory increases velocity to the point of when you need to ask yourself on a turboed application, when is there too much?

My opinion...


Steve - I just love this.

No doubt - "Velocity... NA vs Turbo I think are two entirely different principles." All would agree that inertia and sonics would be even more critical as the velocity and weight of a fluid moving through a pipe is increased. At the beginning of the jet age, aerospace engineers had to learn new things about the behavior of air (as a fluid) when moving at supersonic speeds.

I finally got Corky Bell's Maximum Boost and read about half of it this last weekend. Good book but he says NOTHING about porting in boosted applications.

Can anyone point us to an expert/author who DOES discuss this question of porting - boosted vs NA?

[Mr overkill]

thats what im worried about not many people know the RIGHT way to port one of these intakes


they just get out the grinder and open and open


i know air flow is important but Velocity is to i don't want to be there sitting there and hit the throttle and have to wait lol



the only people here i see that can do it is

chris
cindy
mopar2ya
lownwolf
foward motion

if i am missing someone please dont get mad i just forgot ya lol

[turbovanman²]

You don't need them if your a capable grinder. You just need to carefully open up the runners with a die grinder and match the top holes.

[glhs875]

With the ported runner bolted to the head, flow is VERY stable. Before, the vertical manometer which is what you set to for your test pressure used to fluctuate a tad above and below (only like 1/16" inch which translates to 1-2 cfm) with this runner, it stays dead where I put it and has different sound.

Velocity... NA vs Turbo I think are two entirely different principles. I plan to run up to the 3-bar limit which is stuffing 3 times the air it would normally ingest in NA form... which in my theory increases velocity to the point of when you need to ask yourself on a turboed application, when is there too much?

My opinion...


Well a turbocharger doesn't really increase the airflow into the cylinder. It mainly makes it more dense. If it did increase the airflow into the cylinder, then the power in the upper rpms would be extended alot (more useable RPM's.) NA porting principles seem to still hold true at dictating the rpm power band. At least it does with me. I've seen dyno sheets of 200+cfm heads that only had a HP peak still around 6000rpm. Which just slightly more than stock peak numbers, but of course with alot more overall HP & torque. The cross sectional area of the port will need to be increased if a higher rpm power peak is wanted.

[Directconnection]

Well a turbocharger doesn't really increase the airflow into the cylinder. It mainly makes it more dense. If it did increase the airflow into the cylinder, then the power in the upper rpms would be extended alot (more useable RPM's.)

*Cubic* Feet per Minute. Correct. But, technically, more air is still going through the engine via more boost. If you had a 6 foot diameter sewer pipe and 10 fish were to swim through it at 2mph, no biggie. But if you had 10,000fish trying to get through the same sewer pipe, now you have more dense "fish boost" and need more sewer volume.

[Directconnection]

thats what im worried about not many people know the RIGHT way to port one of these intakes


they just get out the grinder and open and open


i know air flow is important but Velocity is to i don't want to be there sitting there and hit the throttle and have to wait lol



the only people here i see that can do it is

chris
cindy
mopar2ya
lownwolf
foward motion

if i am missing someone please dont get mad i just forgot ya lol


Do some research on the "intake porters" and then you'll want to start a new list.

I don't claim to have intake porting down to a science, but so far cutting my lower half of the intake's flow losses by more than half is very good I must say. Hoping more improvements will actually cut it even more.

Stephane was able to bolt on his 8v intake and pick up flow 9only a couple cfm) and the guy at my shop says a SBC drops flow over 30 cfm with an intake, and after porting in the plenum, he sees a 20+ cfm gain!

Remember... there's a difference between advertised claims and factual information.

[Mr overkill]

i know that steve thats where my problem is i dont want to spend almost 200.00 for slight benefits


and i dont know who to "add" or take out of the list you know but some people say open it up and dont worry about volume others say be careful and dont disturb the balance

lol


so im confused :)

[glhs875]

*Cubic* Feet per Minute. Correct. But, technically, more air is still going through the engine via more boost. If you had a 6 foot diameter sewer pipe and 10 fish were to swim through it at 2mph, no biggie. But if you had 10,000fish trying to get through the same sewer pipe, now you have more dense "fish boost" and need more sewer volume.

I can agree somewhat. But without the 10,000 fish causing a restriction, no boost would be made. No restriction, no boost! When one goes from say a stock turbo to say a T3/T4. You might go some faster while keeping the same boost level as before. If so it's mostly due to better efficiency (lower charge temps). But tap into the higher boost pressures that a T3/T4 can give, and alot more power can be made. But it will still be in the same basic RPM range as before, unless the port area is made larger than before. About 300ft per sec is all air wants to travel no matter how many cfm a port will flow. And that is determined by cross sectional area of the port vs. the bore and stroke of the cylinder it is feeding. And if I had to guess. Compressed air may even fizzel out at less speed as the boost will make the air heavier (more dense). And so even slightly more port area than when NA might be needed to get the desired results.

[LynX853]

can i get a hell yeah for fish boost?!?

[John B]

The upper piece is more restrictive than the entrance to the lower piece! Why shouldn't the upper be opened up to match the entrance to the lower? The lower tapers down dramatically to increase velocity at the head as it is.
Can anyone explain to me the purpose of the two-port design, i.e. from small to larger to smaller again? It makes no sense to me.

[johnl]

Well a turbocharger doesn't really increase the airflow into the cylinder. It mainly makes it more dense. If it did increase the airflow into the cylinder, then the power in the upper rpms would be extended alot (more useable RPM's.) NA porting principles seem to still hold true at dictating the rpm power band. At least it does with me. I've seen dyno sheets of 200+cfm heads that only had a HP peak still around 6000rpm. Which just slightly more than stock peak numbers, but of course with alot more overall HP & torque. The cross sectional area of the port will need to be increased if a higher rpm power peak is wanted.

Good stuff.

The question then is - cfms - but at what density? The engine's displacement is fixed. So, for any given rpm, the CFMs to be pumped are fixed too. That leaves the only variable - density. And density is why, in NA porting/tuning sonics and overlap and reversion and the like are so important - the ability to raise the density of the charge that fills the cylinder without boost - to trick the system's inertia and sonics into packing a gallon of air into a space the size of a quart.

With boost, such subtleties are simplified - just ram it in - but when you get to the upper end of boosted performance, then the same old principles and subtleties return? But now they are applied in terms of a thicker, heavier, denser air? And, what does that mean?

[turbovanman²]

See, I beg to differ, yes were making the charge more dense but were sure as hell putting more in air and oxgyen as well, which is part of the dense equation, add fuel and bam, we have more power. You quote air figures etc but I don't believe that works, otherwise you wouldn't have 1200 whp 2.2 and 2.4L engines. Bryan aka Lugert made over 300 whp on a stock engine with a big turbo, so that proves that RAMMING it in works. :D

[John B]

And while I'm asking questions, what's the torque on the bolts that hold the two-piece together?:confused:

[glhs875]

See, I beg to differ, yes were making the charge more dense but were sure as hell putting more in air and oxgyen as well, which is part of the dense equation, add fuel and bam, we have more power. You quote air figures etc but I don't believe that works, otherwise you wouldn't have 1200 whp 2.2 and 2.4L engines. Bryan aka Lugert made over 300 whp on a stock engine with a big turbo, so that proves that RAMMING it in works. :D

Those really high HP engines have 2 things over an 8V to start with. A higher flowing head with more valve area, and larger cross sectional ports. Those engines are also running HIGH boost, like 40+psi in some setups. What boost pressure did it take to reach that HP on Bryan's setup? I bet it was pretty high. Again, if a turbo actually pumped alot more cfm into the cylinder, than the rpm power band would extend big time. It will extend a little from the increased number of oxygen molecules within the same area from it being compressed. A turbo mainly amplifies the power band that the engine would have it it were NA. It doesn't extend that power band a drastic amount. The entrance of the ports on my 8V head has the same basic cross sectional area of a 16V. The ports on my head measure around 1.9" X 1.2 = 2.28 sq in. The ports on an unported Neon DOHC 16V intake I have measure around 1.74" X 1.285" = 2.24 sq. in. On a stock unported G head the entrance of the ports measure around 1.6 X 1.15 = 1.84 sq in. These measurements are give or take a smudge as it's kinda hard to get a very accurate measurement, but well close enough to get the idea of what Iam talking about. One other point is the 16V heads tend to swell and get larger closer to the valves, and our unported 8V ports tend to get a little smaller than the entrance of the port is closer to the valve. This will help explain why a 16V head will rev higher with power than what a ported 8V head will if the cross sectional area of the ported 8V head is not as great as a 16V head. Even if the 8V head were to flow as much as 200cfm or more which is not far off from what a some stock 16V heads flow. It's sure not the cam difference between the 2 that gives a 16V more revs (on our engines anyway), as stock 16V cams are usually more mild than 8V cams are. Although larger cams can help and extend upper rpm power somewhat.

[glhs875]

Good stuff.

The question then is - cfms - but at what density? The engine's displacement is fixed. So, for any given rpm, the CFMs to be pumped are fixed too. That leaves the only variable - density. And density is why, in NA porting/tuning sonics and overlap and reversion and the like are so important - the ability to raise the density of the charge that fills the cylinder without boost - to trick the system's inertia and sonics into packing a gallon of air into a space the size of a quart.

With boost, such subtleties are simplified - just ram it in - but when you get to the upper end of boosted performance, then the same old principles and subtleties return? But now they are applied in terms of a thicker, heavier, denser air? And, what does that mean?

Highly tuned NA engines use scavenging within a certain rpm range to increase flow not necessarily density. Not gonna happen with a backpressure cork of a turbine housing hung on the end of a header when turbo'ed

[Directconnection]

i know that steve thats where my problem is i dont want to spend almost 200.00 for slight benefits


and i dont know who to "add" or take out of the list you know but some people say open it up and dont worry about volume others say be careful and dont disturb the balance

lol


so im confused :)

If you're not sure, then play the safe approach and do the "be careful and don't disturb the balance" ;)

I'm doing both.

We'll see how she comes out in the end.

[Directconnection]

The upper piece is more restrictive than the entrance to the lower piece!

No it is not. It sure appears that way, though. The lower half contributes to 2/3rds the flow losses of the top half.

If you are an SDAC member, I fed alot of flowtest data from 4 intakes I flowed on all 4 runners and then flowed two lower halves as well... 24+ individual flowtests to Baryy for the newsletter last summer.

[turbovanman²]

And while I'm asking questions, what's the torque on the bolts that hold the two-piece together?:confused:

I just do them hand tight, start from the center and work out like a head gasket and use a dab of blue loctite.

[mpgmike]

As for porting intake manifolds, the average person can get about 85% of the possible added flow just by removing the barriers at the lower corners and the "ski jump" right behind the injector area. Open the port to just under gasket size, and keep that cross sectional surface area the whole way back. On the 1-piece, the port gets larger as you approach the plenum. Open the outlet to gasket size back to that widening.

On the 2-piece, you have to make a transition from relatively rectangular to round. It is extremely easy to break through on the 2-piece intakes around the obstructions in the lower part of the port openings. Also on the 2-piece, the upper and lower DO NOT get ported to gasket size. I made up a template that utilizes the normal flow characteristics in that elbow area to simply blend the two. It is also important to keep the outside radius characteristics so there is not a pointy recessed area when the 2 pieces are rejoined.

Removing the elbow and grafting in a larger one is the only way to get more than stock throttle body flows, as the neck cannot be ported larger and only flows about what a stock TB flows. Adding a 52 mm TB won't give you more flow, even blending the throat of the neck.

To get that last 15%, careful reshaping around the injector area can help dramatically (within the last 15% margin), and attention to detail as the cross sectional surface area is shaped will add a little also.

Over porting won't help either, as you have a drop in velocity. Ideally, you want the ports to funnel down from the plenum to the short side radius in the intake port, where it is OK to have a little expansion area to assist the transition from horizontal to vertical. The intake port in the head and the intake port in the manifold act as one integrated unit when they're bolted together.

I hope this helps.

Mike-TU

[johnl]

Highly tuned NA engines use scavenging within a certain rpm range to increase flow not necessarily density. Not gonna happen with a backpressure cork of a turbine housing hung on the end of a header when turbo'ed


Got it. Sort of like taking the expansion chamber off of a two stroke and sticking a turbo on it.

Oh, Mike, that was a great post too.

[Dave]

I'm not much help here, but with a setup like that, why skimp on the intake? Sure you can make good HP on the stockers, but look at Garrett and 8valves. Just saying, if you're puting all this money into a nice setup, why not compliment?

[Vigo]

I'm not much help here, but with a setup like that, why skimp on the intake? Sure you can make good HP on the stockers, but look at Garrett and 8valves. Just saying, if you're puting all this money into a nice setup, why not compliment?
my thoughts exactly.. if you want to keep pushing the setup and improving it later, you'll save yourself time by doing this part now, so you can skip to making progress in places that advance the game, and not spending a bunch of time messing with half---- intake manifolds and then eventually going back and doing what garrett and aaron and supercrackerbox and others have done, only after a bunch of wasted time figuring out stuff other people coulda told you in the beginning. stock intake manifolds cant keep up with the rest of a good-flowing setup, the runners are too long and the plenums are too small. porting is a good way to get from stock to mild on these intakes, but to go big you have to seriously change them.

[boost geek]

Removing the elbow and grafting in a larger one is the only way to get more than stock throttle body flows, as the neck cannot be ported larger and only flows about what a stock TB flows. Adding a 52 mm TB won't give you more flow, even blending the throat of the neck.



I hope this helps.

Mike-TU

I know I've posted this pic a few times, and it's off a 1 piece, but I would think a 2 piece would be similar. 2.2 on the left, 3.3 on the right. If your gonna open up your intake, I would recommend doing the elbow too...
http://i91.photobucket.com/albums/k302/boostgeek/2005_1007Image0105.jpg

[Mr overkill]

thats where im at if it was worth it "actually worth it" then i have no prob doing it but at the same time didnt want to waste it still need other stuff to buy you know !!!

[John B]

I would think a 2 piece would be similar. Actually, the two-piece is much better in the elbow.

[glhs875]

Actually, the two-piece is much better in the elbow.


Yes it is. It doesn't neck down like the 1 piece does.

[johnl]

Mike, you said -

"To get that last 15%, careful reshaping around the injector area can help dramatically (within the last 15% margin), and attention to detail as the cross sectional surface area is shaped will add a little also."

At the bottom of the lower half of the 2 piece, where it bolts to the head, when I look at the bolt bumps below and the cavity around the injectors above, I wonder "Do they balance each other out?" Would it hurt the injectors' function to fill in that cavity? Does they spray pattern depend on turbulence caused by the low pressure created by that cavity? And, considering that the cavity/point of low pressure would slow port velocity, do the bolt bumps below create an area of high pressure, such that overall velocity, say in the center of the port, is maintained?

Steve? Mike?

[Directconnection]

Nobody here could answer that without testing an injector while flowing the bench, and/or running it on an engine to find out for sure... I removed the bolt humps and picked up 2 cfm with the head bolted to the intake from this mod alone. The injector area... I thugh about filling it up, but would rather leave that are alone to be on the safe side. All I did was some blending and I radiused that flat spot opposite where the injector sprays and which is the manifold's mating surface if you know what I mean. You have the roof of that runner in the manifold, then an open space where the injector is at and I visualize th flow expanding and then hitting that flat little wall on the roof still which could lead to a flow restriction of sorts... so I made a ramp and then radiused it.

Wish I had time to just port one key area at a time to make sure EVERYTHING is a flow reduction instead of 15 at once.

[glhs875]

Mike, you said -

"To get that last 15%, careful reshaping around the injector area can help dramatically (within the last 15% margin), and attention to detail as the cross sectional surface area is shaped will add a little also."

At the bottom of the lower half of the 2 piece, where it bolts to the head, when I look at the bolt bumps below and the cavity around the injectors above, I wonder "Do they balance each other out?" Would it hurt the injectors' function to fill in that cavity? Does they spray pattern depend on turbulence caused by the low pressure created by that cavity? And, considering that the cavity/point of low pressure would slow port velocity, do the bolt bumps below create an area of high pressure, such that overall velocity, say in the center of the port, is maintained?

Steve? Mike?


I don't like the way the ports are in these 2 areas on a stock intake at all. I had my 2 piece runners welded so I could completely remove the humps and smooth the runners and to get the cross sectional area needed and consistant to the ports on my head all the way to where the intake bolts to the head. When it comes to ports, it doesn't matter how large the opening or exit is, if there is a smaller area in between these 2 points that smaller area will be the choke point, and will actually cause a low pressure area after the choke point, slowing velocity and can be the limiting factor to flow. Same principle that happens withing the booster area of a carb. I haven't yet, but I plan on filling and smoothing the injector boss area. It looks like a place for turbulence to me. I have some porting epoxy to do this with but have yet to do so. All I did so far is raised/ tapered and smoothed the wall of the cavity at the exit. I also raised the roof of the runner slighltly before the cavity to get the cross sectional area needed to match the port on my head. My 8V feels more like a 16V at WOT. With the SC 6152 turbo, the fat part of my powerband is from 5500 to 7000 +rpm with a stock T1 cam and even higher rpm's when I had the S3 cam installed. But I had valve float problems(working on it) that was keeping me from getting all the good from the S3 cam. I'm in the process now of complimenting the power within this range, as this range of rpm's seems to work real well for a wild street /strip setup to me. I'm gonna keep working on my 8V combo at least until I get the known street radial tire record (not DR's) (at least in the 1/8th), that is currently 7.781. And that was done by a 16V L body. I'm getting close!!! I'm basically down to just a killer launch away!

[mpgmike]

There are 2 ways of homogenizing an aerosol fuel mist into the air stream:
1- create a low pressure area, the way a carburetor does, and the way the factory intakes apparently attempt to do.
2- place the aerosol into the high velocity part of the air stream where the velocity will do the work of acting as a carrier fluid.

The little bit of additional vaporization that can occur due to the constriction in the injector area is of little significance; and this is coming from somebody that specializes in improving vaporization. The gains from additional flow will far outweigh any little vapor loss. Square this area out (not make it square in shape, but consistent in CSA) and run it back and blend it with the larger portion of the port. A ported head with a restrictive manifold just doesn't make sense at all. Even a stock head can benefit noticably from porting the intake ports in the injector area.

Mike

[johnl]

The injector angle is such that about half of the injectors' spray points directly at the wall that Steve referred to. At least it looks that way. If you're gonna fill the void, then change the angle so the spray is more to the center of the port?

On the other hand, since lots of TDs run big injectors with AFPRs and lower than stock fuel pressure, maybe its a good thing that there is a low pressure spot immediately down stream of the injector - at least during off boost and at lower engine speeds.

Heck, at this point it's nats and nits, other than what's been said, and in the absence of data - as opposed to speculation, leave it alone.

[Vigo]

i referenced someone wrong, i meant rattlesnake..oops! (let me edit!)

[8valves]

There are a few things that people have mentioned that I think should be cleared up... the big power cars that some were speaking of, severe race cars or silly street car setups making 700+++++ or whatever number you want to put to it likely don't have a pressure ratio like people tend to think.

The well setup cars can achieve or at least get near a 1:1 pressure ratio intake to exhaust, regardless of the turbo hanging off your header. Especially when the wastegate(s) opens.

Also, you can't compare a 16V design to an 8V design. The single most important factor in your engines powerband characteristics is the cam, and a 16V car can run more aggressive cams without any sacrifice in overlap. Timing events can be dialed in seperately between intake and exhaust, so pretty much everything is controllable. With a single cam engine regardless of the number of valves you have to make compromises in cam selection and timing.

Having said all of that, I think that intake side modifications should generally follow somewhat to traditional NA porting styles and ideas, but the exhaust side is a whole different story. Its the same principles being applied that lets flow numbers be more of a measurement than a standard when it comes to FI setups.

To answer the original question, I think it could help you. But with using a generic setup ECU the gains won't be as noticeable.

[Mr overkill]

so i am going to just port it gonna send it out next weekend i hope

[turbovanman²]

so i am going to just port it gonna send it out next weekend i hope


To whom?

[Mr overkill]

mpg . since he is the next state away and im gonna be in the area so shipping would be nothing

[Dave]

mpg . since he is the next state away and im gonna be in the area so shipping would be nothing

How much is he charging you? Not to be a nit pick, but Aaron is building me a large box plenum for $300.

[DB-Rocket]

They say not to port the top half of a 2 piece.

Then you hear of people making big box plenums to replace the top of a 2 piece.
Whats the difference? :confused:

[Mario]

They say not to port the top half of a 2 piece.

Then you hear of people making big box plenums to replace the top of a 2 piece.
Whats the difference? :confused:

No "they say" not to gasket match the upper lower joint point. Creates sort of a bubble there so to speak if you don't full port the entire runner length.

[turbovanman²]

They say not to port the top half of a 2 piece.

Then you hear of people making big box plenums to replace the top of a 2 piece.
Whats the difference? :confused:




No "they say" not to gasket match the upper lower joint point. Creates sort of a bubble there so to speak if you don't full port the entire runner length.

Yes, thats what they say but then people have port matched both with no problems. I guess its based on setup. Mine wasn't that wild so I just port matched the lower to the gasket and left the upper alone.