TU Header flow?

[John B]

How does the TU header flow compared to a well ported stocker?

[rbryant]

Night and day difference...

I don't remember the numbers I heard but it was much much better than a ported manifold.

Plus I can take my turbo off in 15 minutes and put it back on in another 20.


-Rich

[tryingbe]

http://www.turbododge.com/forums/f4/f16/127231-t-u-header-vs-ported-manifold.html

[MiniMopar]

Save for the Pope-related bickering, that was a pretty good thread.

As a local follow-up to a question posted there: has anyone had any durability issues with these "Schedule 40" style log manifolds? The one regret I have with the setup on my Daytona was not upgrading the exhaust manifold. I have an FM ported unit, but I am quite certain that is my biggest cork. It would probably help spool-up too.

[Warren Stramer]

I hope I don't make this sound like a slam against anyone's hard work or products but.........................Ive yet to see ANY difinitive proof (Engine dyno, chassis dyno, or controlled track test) where a log type exhaust "header" made one ounce more power than a properly ported stocker, and I would not be suprised if they would make less power.(all other things being equal)
The only tests I have seen on them are irrelevant flow tests. since when does high cfm flow (alone) in an exhaust manifold equate to more power? especially in a turbo application. Who started this folly?
I have seen some beautifully crafted welded el manifolds here but they are all essentially nothing more than a exhaust plenum with an exit opening for the gas to escape to the turbine.
Again, I do not wish to insult anyone or there work, I just hate to see all that time, money and energy go into these log manifolds only to see your car go slow down. Someone prove me wrong.:o Warren

[BadAssPerformance]

+1 to that! ...back-to-back dyno or track times is the only way to know for sure :thumb:

Warren, you went 10's on a ported stocker before building your beautiful header right?

[turbovanman²]

Get ready Warren, your wish will come true, sort of, without the dyno info though. :thumb:

Have you dynoed them all or ?


BTW, didn't you go faster with a header? :eyebrows:

[BadAssPerformance]

Get ready Warren, your wish will come true, sort of, without the dyno info though.

Have you dynoed them all or ? :thumb:

BTW, didn't you go faster with a header? :eyebrows:

Really, somene is doing back to back dyno testing? Sweet!

Dude, his header was going 200mph just sitting on the engine stand! :thumb:

[turbovanman²]

I know Warrens new header is sweet. Just curious as to what he found using stockers, logs etc.

Reeves runs a log header and he's making insane power.

[Warren Stramer]

+1 to that! ...back-to-back dyno or track times is the only way to know for sure :thumb:

Warren, you went 10's on a ported stocker before building your beautiful header right?

Yes, went 10.81 with ported stocker, and gained 4 mph with the header, but I'm not talking about a tubular header, I'm refering to all the "log headers" everyones building. My point is I think they are a waste of time!!!
and I would bet in a controlled scientific test they make LESS power.

[Warren Stramer]

I dont know exactly what James is running but I bet he would make insaner:D power with a tubular header.

[BadAssPerformance]

Gotcha. I hear you on the why would a log header be better than a ported stocker since it itself is a log. I could possibly see a well designed log doing as good or better than a well ported stocker. Like you said, scientific, dyno type testing needed.

[BadAssPerformance]

I dont know exactly what James is running but I bet he would make insaner:D power with a tubular header.

At Topeka last year it was a ABM log type...

Tubular headers are cool :thumb:

[Warren Stramer]

I guess what I dont understand it why so many people are putting on log manifolds when I has not been proven that they improve anything over a ported stocker or even a stock stocker!

[BadAssPerformance]

Bigger is better?

Check box on the magical build up list?

:)

[turbovanman²]

Yes, went 10.81 with ported stocker, and gained 4 mph with the header, but I'm not talking about a tubular header, I'm refering to all the "log headers" everyones building. My point is I think they are a waste of time!!!
and I would bet in a controlled scientific test they make LESS power.

I was going to do that but as you know, you start changing one thing and then another and its no longer a true back to back test.

Have you tried a log header? I believe in the Civic world, they do work.


I dont know exactly what James is running but I bet he would make insaner:D power with a tubular header.

Maybe, :eyebrows:


I guess what I dont understand it why so many people are putting on log manifolds when I has not been proven that they improve anything over a ported stocker or even a stock stocker!


Well isn't flow and even flow everything? a stock manifold is good but a log header flows more, or it should and theoretically, its more even, which is what we want, right?

[BadAssPerformance]

I just noticed that this thread is titled "TU header flow" and I would like to make the point that none of the recent discussion is in reference directly to or about TU products.

Chris, please advise if you would like us to re-name the thread or split up these discussions.

[turbovanman²]

Well its John B's thread, ;)

[BadAssPerformance]

Nooo shiiiit.... but titled TU... should actually have been moved at the start to the TU vendor section?

[turbovanman²]

Nooo shiiiit.... but titled TU... should actually have been moved at the start to the TU vendor section?

Nah, he's just looing for user info, I think its fine here, :nod:

[Warren Stramer]

Most of the log manifold I see being built have no separation of cyl to cyl exhaust pulses. The tubes are too large, basically just pumping the exhaust out of the cyl head ports into a plenum. The reversion must be horendous, and gas velocity has to go in the toilet.
The stocker at least has a little better cyl separation. and they are dirt cheap.

[BadAssPerformance]

Nah, he's just looing for user info, I think its fine here, :nod:

Should we re-name it then?

[BadAssPerformance]

Most of the log manifold I see being built have no separation of cyl to cyl exhaust pulses. The tubes are too large, basically just pumping the exhaust out of the cyl head ports into a plenum. The reversion must be horendous, and gas velocity has to go in the toilet.
The stocker at least has a little better cyl separation. and they are dirt cheap.

Good points... especially in a turbo manifold... velocity, flow, equal pulse seperation and of course manifold pressure all have to work together. A true log seems to be more a pressure resivior than any of the other attributes.

[Warren Stramer]

Well isn't flow and even flow everything? a stock manifold is good but a log header flows more, or it should and theoretically, its more even, which is what we want, right?
An exahust valve/port has a finite flow potential, as does the turbine. as long as the tube/ manifold connecting the two is not a restriction than it cannot improve flow by making it any larger than is neccesary to transfer the gas volumn.
with a turbo restricting the flow of gas it becomes even more important to keep gas velocities as high as possible, AND to maximize cyl to cyl separation. both benefits are defeated with a log manifold.

[turbovanman²]

An exahust valve/port has a finite flow potential, as does the turbine. as long as the tube/ manifold connecting the two is not a restriction than it cannot improve flow by making it any larger than is neccesary to transfer the gas volumn.
with a turbo restricting the flow of gas it becomes even more important to keep gas velocities as high as possible, AND to maximize cyl to cyl separation. both benefits are defeated with a log manifold.

Ok, but what if the flow is uneven in a stocker?

Back to Reeves, he figures he's cranking out 450 whp or so, do you think the log is a problem?

[Warren Stramer]

450 whp is definetly not a problem Simon, unless your leaving 40 hp on the table;)

[Warren Stramer]

The ABM header I saw photos of was not really a log manifold in the same vein as the type a lot of people are coppying, it appeared to have better cyl separation. Anybody got a picture of the ABM header?

[BadAssPerformance]

I think it had the runners kind of "Y" into the plenum kind of directing flow rather that "T" into it?

[John B]

I didn't anticipate such an interesting discussion! I have a really well ported stock manifold but I'm always looking for more power.:amen:

[Ondonti]

Simon, i would say the honda world has definitely proved quite the opposite. If you arent running an equal length ram style top or bottom mount then you are also not going to be able to use some of the giant turbos SFWD cars are using to compete.

My rear 3.0 manifold is made using 90 deg bends rather then the lazy T welding design. Still not a good design though.

[glhs875]

An exahust valve/port has a finite flow potential, as does the turbine. as long as the tube/ manifold connecting the two is not a restriction than it cannot improve flow by making it any larger than is neccesary to transfer the gas volumn.
with a turbo restricting the flow of gas it becomes even more important to keep gas velocities as high as possible, AND to maximize cyl to cyl separation. both benefits are defeated with a log manifold.

I agree. And what do I have on my GLHS? A log!! I honestly feel it is hurting me! My Daytona ran quicker and faster and weighed more than my GLHS with an almost identical setup. The only things being different were cam, turbo, and exhaust manifold with the Daytona having a highly ported stocker. And all of the differences that the GLHS has, should make it quicker than the Daytona!! I will go to a true tube header in the future. In fact, after this next round of mods, that will be the only change I will make other than tuning for it, and will provide a good comparison.

[MiniMopar]

One thing the log has going for it is packaging. The Sched40 logs have the same advantage, plus some flexibility with the turbo flange that can simplify the use of a hybrid or other, more standard turbos.

I honestly haven't seen any tubular headers that don't require drastic changes to how the turbo mounts and all the headaches that go with it. Am I missing something? It seems like a non-equal length tubular header shouldn't be too difficult to implement....

Back on the subject of logs: the ported FM stocker that I have seemed pretty nice. The walls were a bit thin in some places, but they really got in there. How do they compare to other ported stockers out there, I wonder?

[Directconnection]

Gotcha. I hear you on the why would a log header be better than a ported stocker since it itself is a log. I could possibly see a well designed log doing as good or better than a well ported stocker. Like you said, scientific, dyno type testing needed.

But a stock exhaust manifold is a log style manifold.

Warren, I just finished up some extensive flowtesting of exhaust manifolds from stock, ported stockers, log headers, and a tubular header.

I too, was skeptical of the log headers out there, but I will say that I am no longer skeptical and will never run a stock production exhaust manifold again from what I learned.

As for test methods... I tested each individual runner while bolted to a stock g-head from .100 to .500" lift. I also flowed them on a test plate on my bench doing each runner seperately as well.

[Directconnection]

I have a couple pages of the data written down from pages of flowtests, but I will give a rundown on just the flow gains/losses in cfm with the manifold bolted to the head, and at .500" lift. Also, I bolted the manifold down to exhaust runner #2 on the bone stock g-head and simply used the same head runner for all manifold runner tests (and blocking off the other runners of course) this way there was no variance of different head ports being used (and less math, too). Used the same exhaust head port for all tests. I also had a 3" spacer between the headstand and head for exhaust manifold clearance.

Stock G-head *alone* at .500" lift: 127.7 cfm

Stock exhaust manifold:
#1) 1.4 #2) -17.2 #3) 7.4 #4) 6.9

Vendor A ported stocker:
#1) 1.7 #2) -17.7 #3) 6.9 #4) 6.5

Vendor B ported stocker:
#1) 5.1 #2) -15.0 #3) 9.8 #4) 20.5

Vendor C ported stocker:
#1) -.3 #2) -16.7 #3) 9.3 #4) 4.3

Vendor A log header:
#1) 3.1 #2) -5.8 #3) 1.3 #4) 11.1

Vendor B log header:
#1) 3.9 #2) -3.5 #3)no test #4) 10.9

Vendor C equal length header:
#1) -1.3 #2) -2.8 #3) -3.7 #4) 3.2

Vendor B PORTED by Steve Mercier:
#1) 11.1 #2) 10.5 #3) 17.2 #4) 12.7



I also performed another flowtest on these manifolds on a SF-300 at 10",28" and 45" but never got around to crunching the #s and also had a few test situations with 45" creating so much heat that the tape on the other ports would vibrate off on some and I tried my best to keep an eye on. Doesn't appear that at 45" that they flow alot more air as I expected, but it does appear that they do flow more, especially the larger volume ports.

A 1 cfm gain over what the head flows is a pretty big gain to be asking of, so take these small flow increments in terms of more like a stock head that flows 140cfm, and a big valve head that flows 200+

[NeonShowCar]

So - you gonna fess up Steve? ;)

It would be a good thing to show runner-to-runner distrubtion of these manifolds. Do you know the distrubtion of each manifold?

*Edit*

Just looked over your numbers. Man, those stocks flow like crap. Look at the runner to runner distrubtion. Your last numbers "vendor b ported by steve" --- what manifold? Log? Stock? You seem to forget to mention that. ;)

Oh another thing -- doesn't anyone have a FAQ where data like this could be stored?

I've been outta the loop for so long - but lets just say, not for much longer. I love seeing data like this. and its very important to save this sort of data, in a central location. Maybe Frank can make up a page like he did for the cylinder head flow work. Right Frank? :)

[show-off]

Stock G-head *alone* at .500" lift: 127.7 cfm

Stock exhaust manifold:
#1) 1.4 #2) -17.2 #3) 7.4 #4) 6.9

Vendor A ported stocker:
#1) 1.7 #2) -17.7 #3) 6.9 #4) 6.5

Vendor B ported stocker:
#1) 5.1 #2) -15.0 #3) 9.8 #4) 20.5

Vendor C ported stocker:
#1) -.3 #2) -16.7 #3) 9.3 #4) 4.3

Vendor A log header:
#1) 3.1 #2) -5.8 #3) 1.3 #4) 11.1

Vendor B header:
#1) 3.9 #2) -3.5 #3)no test #4) 10.9

Vendor C equal length header:
#1) -1.3 #2) -2.8 #3) -3.7 #4) 3.2

Vendor B PORTED by Steve Mercier:
#1) 11.1 #2) 10.5 #3) 17.2 #4) 12.7


Steve,
Can you interpret these numbers for those that might not be as knowledgable as some in the community.

What are the effects of such large disparities between cylinders 1,2,3,4?
What happens when you have a a couple cylinders close to the same with others 15-20 cfm differnt.
What is the perfect scenario?

Those kinds of questions might help others understand this better.

[CSXT802]

Steve,
Can you interpret these numbers for those that might not be as knowledgable as some in the community.

What are the effects of such large disparities between cylinders 1,2,3,4?
What happens when you have a a couple cylinders close to the same with others 15-20 cfm differnt.
What is the perfect scenario?

Those kinds of questions might help others understand this better.

+1^:)

[Warren Stramer]

Steve, I guess maybe I was not clear enough on my first post, If I may present this in a different way. First of all I am NOT saying I have any emphirical proof that a scedule 40 type header will hurt power, It is simply my opinion based on research on the subject nothing more.
Having said that, could we agree that the exhaust tube/runner of the header is just an extention of the exhaust port? and if the exhaust port flows say 160cfm that we need the header primary tube to flow that amount as well?
And would you agree that changing the cross section of this port extention (sudden increase in diameter from cyl head port to header tube)will cause velocity to drop?
and that the decrease in diameter and velocity will also precipitate a temp drop.
and that a temp drop and less gas speed is counter productive in driving a gas turbine?

Have you measured flow velocity with a pitot probe?

If the exhaust runner cannot keep up with the flow rate of the exhaust port than yes you may benefit from a higher flow rate but I would not want any more volumn than it would take to satisfy the needs of the cyl. head. I would not trade velocity for volumn.

I think flow testing headers is interesting but misleading........like adding up all the numbers in the phone book to find the average phone number....what does it really tell you:)

[BadAssPerformance]

... I think flow testing headers is interesting but misleading........like adding up all the numbers in the phone book to find the average phone number....what does it really tell you:)

I have to agree with the misleading part, especially in a turbo application...

[MiniMopar]

I think everyone agrees that the stock manifold has some trouble spots. So I guess it is a question of whether or not going to the large sched40 diameters hurts velocity more than it helps flow through the restrictive parts of the stocker, namely the area between #2 and #3....

There are too many variables for my brain to parse. Empirical testing is probably the only way to know for sure.

[Directconnection]

I am at work and can only give a quick response: The log headers I tested... you can just feel/see/hear increased velocity.

I've always theorized what you wrote, warren. Heat energy drives the turbo and large volum ports make the gasses expand and probably losing some of it's thermal energy of sorts. But i feel the greater flow outweighs this big time. If you saw them run on the bench and could hear them, you'd probably be a believer as I was AFTER the tests. I was a wlded el hater before this:eyebrows:

Also, your awesome tubular header you made... technically one could say that it's losing alot of thermal energy as the turbo is way upstream, but you know what.... it works, right? Maybe the equal length outweighs other aspects like flow losses through long tubes?

Short tubes (to better transmit thermal energy) and decent flow may be outweighing the large volume issue on these welded el headers.

Adler is a believer of the one I tested as it came off his car.:)

[Ondonti]

If the issue is "what makes more power"
I dont think cylinder to cylinder flow tests can prove anything except....
When an engine is not actually operating, flowtests of a single exhaust port can have very good results through a log manifold (especially one that is ported by so and so).

The test doesnt simulate what actually happens when the engine is running, and what actually happens when the engine is running is what will have the final say on the power numbers.

Even if you could flowbench all 4 exhaust ports at the same time and deduce what percentage of flow was attributible to each cylinder, that would ignore the fact that exhaust is not a constant flow out of the exhaust port.

This is a question of power so a dyno is part of the solution.

I stick with the idea that log headers will NOT spool the big turbos used in high hp small engine setups. If you are using a tiny turbo then you probably can make the same power with a log but when it comes to using a turbo that the log cannot create a usable powerband with, We must conclude that the tubular header is superior, and possibly VASTLY superior in power production.

I think it is a very well documented fact that log headers cannot make boost on large turbos (large for the engine) so the only argument to make is ...WHY.

Just because someone does not know why, that does not refute the fact that "more power" is happening.

To me it is indisputable that tubular headers make more power then log headers. The evidence plays out in racing every day.

Put a log exhaust manifold on stephanes car and watch performance drop off. You guys are not at the level of fitting gt42 or larger turbos to 2.x liter engines so you are not dealing with much of the evidence that logs suck.
If he does not have more power, Warren at least has a wider powerband that would be impossible with a log.

[MiniMopar]

A lot of us don't run 10s and/or have huge turbos. A lot of us have slightly bigger-than-stock turbos and drive mostly on the street. Some of them are even DDs. Therefore, there is a lot of other factors at play here, not just ultimate power. These factors include cost, packaging, and convenience.

For ultimate power, I agree that a tubular header is the way to go. I don't think anyone is disputing that. The question I now have is: is a log-style header better or worse than a ported stocker? It probably depends a lot on the rest of the setup, but I think a fair amount of people have:

- some kind of ported head that hopefully flows better than stock
- some kind of bigger turbo, whether it be a Super*0 or some kind of hybrid

I have the impression that the ported stocker might be the cork in my setup. Going to some wacky tubular header is not really something I want to deal with on my DD. That makes a log header an attractive alternative, but only if it helps more than it hurts....

[BadAssPerformance]

I think everyone agrees that the stock manifold has some trouble spots. So I guess it is a question of whether or not going to the large sched40 diameters hurts velocity more than it helps flow through the restrictive parts of the stocker, namely the area between #2 and #3....

There are too many variables for my brain to parse. Empirical testing is probably the only way to know for sure.

Is "Empirical" a brand of dyno? ;)

[Directconnection]

If the issue is "what makes more power"
I dont think cylinder to cylinder flow tests can prove anything except....
When an engine is not actually operating, flowtests of a single exhaust port can have very good results through a log manifold (especially one that is ported by so and so).


Respecting your opinion and reasoning, but I don't agree with this statment. One exhaust port flowing much less than any of the others affects the scavenging properties of that *one* cylinder BIG time. (ever wonder why the #4 supposedly runs leaner? Look at the flow results) Don't believe this, then weld up one of the runners in your manifold to decrease flow, then hog out another so the overall average of all 4 runners come out the same and then see what happens. Besides, this is how the performance industry tests intake and exhaust manifold systems. Yes, a tuned manifold will reap rewards, but tuning is the frosting on the cake. You can dump as much frosting on that puppy all you want to make it better, but if the actual cake still sucks.....


Also, why can't they spool a large turbo? There's alot more exhaust energy from the expanding gasses 6-10" away from the head than there is 2 feet away. That is not debatable. Not being sarcastic, but what is the theory or factual info on why a log header can't spool a realy large turbo?

The design of a log header is crappy, I agree. I would no doubt rather run one of Warren's headers on my car than a log header, so don't get me wrong. The log headers are simply an answer to crappy stockers which also allow you to keep the turbo in the same location. The majority of people on this board (like 95%) could benefit a great deal with using a log header, especially after it's been ported for equal flow. On the other header thread, there were a few people that posted boost increases after switching to a log header. If and when I build a dedicated drag car, I will absolutely build a tube header, in the meantime, I'll stick with a log header for packaging reasons.

[Directconnection]

BTW... Warren, could you post pics of your header here? I think some people should see your work of art (plus, it's nice to give yourself a pat on the back every once in a while;) )

[nomadman2001]

A lot of us don't run 10s and/or have huge turbos. A lot of us have slightly bigger-than-stock turbos and drive mostly on the street. Some of them are even DDs. Therefore, there is a lot of other factors at play here, not just ultimate power. These factors include cost, packaging, and convenience.

For ultimate power, I agree that a tubular header is the way to go. I don't think anyone is disputing that. The question I now have is: is a log-style header better or worse than a ported stocker? It probably depends a lot on the rest of the setup, but I think a fair amount of people have:

- some kind of ported head that hopefully flows better than stock
- some kind of bigger turbo, whether it be a Super*0 or some kind of hybrid

I have the impression that the ported stocker might be the cork in my setup. Going to some wacky tubular header is not really something I want to deal with on my DD. That makes a log header an attractive alternative, but only if it helps more than it hurts....

I share the same view as Russ .....

I just finished a welded ell log header and will be trying it out along with a ported head and .60/.63 turbo on my fresh forged piston motor. Cost, time and simplicity all play a role in the decision. That and the fact that I'm not out to win a race, just have fun.

http://www.turbo-mopar.com/forums/photopost/data/500/medium/IMGP0234.JPG

[tryingbe]

http://www.turbo-mopar.com/forums/photopost/data/500/medium/IMGP0234.JPG


That's a beautiful welded log. How much will you sell it?

[nomadman2001]

That's a beautiful welded log. How much will you sell it?

No, not for sale - this one's mine :eyebrows: . I've been asked to make more but I can't do it right now. Reasons being 1) no time, 2) I want to prove it out for fitament and durability, 3) no time!

I may make a couple/few after this season. My car is dormant over the winter which frees up that valuable element - TIME!

http://www.turbo-mopar.com/forums/photopost/data/500/medium/IMGP0231.JPG
http://www.turbo-mopar.com/forums/photopost/data/500/medium/IMGP0230.JPG

[Warren Stramer]

BTW... Warren, could you post pics of your header here? I think some people should see your work of art (plus, it's nice to give yourself a pat on the back every once in a while;) )

one last time..............:o
http://www.turbo-mopar.com/forums/showthread.php?p=53407#post53407

[BadAssPerformance]

DROOOL!
http://www.turbo-mopar.com/forums/attachment.php?attachmentid=1245&d=1150598399
http://www.turbo-mopar.com/forums/attachment.php?attachmentid=1246&d=1150598568

[cordes]

Absolutely incredible.

[nomadman2001]

Absolutely incredible.

+1 :nod:

[turbovanman²]

OMG:wow1:

That is incredible, once again Warren, a true work of art, :amen: :partywoot:

[Ondonti]

Investigate the Honda, nissan, or even SRT-4 camps and you will find that LOG headers cant spool up the big turbos and make usable powerbands.

Recently its almost been impossible to find someone running fast who has not moved to the not so space efficient Ram style 4 cylinder manifolds.
Whether or not you like the idea, its just a fact that the difference of being able to use a gt42 on a 2.0 liter engine or not is the exhaust manifold.

I cant give an example of someone using a log, small engine, and a big turbo because its just not happening. I have a giant turbo but I have 6 cylinders and Im quite certain if I worked my butt off and replaced my logs with tubular collectors that I could have an insane power band even if i did not try to increase power.


Just wondering about heatloss. It would seem to me that once the long tubular manifold gets really hot, that heat loss will drop significantly.


I understand measuring the flow differences in each port to compare the log and the ported stocker. That seems very useful. I dont think you can compare numbers with a tubular header as.....the log headers and ported stockers allow one port to use the entire flowpath of the log header to move air and ignores the fact that it needs to share this flowpath when actually being used. A turbular header shares nothing until the collector.

So I think in real life the log/stock numbers for each port will drop off significantly once cylinders are competing with each other to expell exhaust gases.

[TurboJerry]

The things I learned are.
1. Boost is a measure of restriction.
2. Compression ratio never changes. Cylinder pressure does.
3. Velocity is very important for efficient turbo operation.
4. Not trying to knock vendors or anybody, but I will only go to a equal length 321 stainless header if the stock manifold does prove to be a severe power/et looser.

[Ondonti]

I did some googling and found conflicting information with what I said in this thread but I dont have time to read it very well or pick it apart.
Sorry this isnt a reference to the actual test performed but
honda talk...scroll about halfway down
http://www.forums.evans-tuning.com/viewtopic.php?p=13004&sid=55897ddcd212ead869cb12013f645364

Then this sr20 debate.
which seems to say the log spools about 200-300 rpms sooner BUT power drops off the instant that 200-300rpm advantage is over. The log makes 5hp (just about exact) more for 200-300 rpms and then makes 50hp!!! less for 3300 rpms.

http://www.sr20forum.com/turbo/84358-equal-length-vs-log-manifold.html

quicker spool in the log seems to be attributed to greater exhaust manifold pressure (A BAD THING) and the moment the turbo starts making boost it start hurting power.

Here is a fairly internet famous test that many of these log threads talk about. Same conclusions but on this test the hp difference is 68whp at peak and Im not sure about the rest of the powerband...but it also makes 44whp more torque.

http://forums.freshalloy.com/archive/index.php/t-110270.html

Anyways as far as I am concerned spooling 300 rpms sooner but losing power right after the turbo starts spooling is not a good deal. An extra 5 hp for 200 RPM is basically worthless.

But if a log manifold can reduce backpressure over a stocker or a ported stocker then that seems like it would be a good thing.


Has anyone dont exhaust manifold pressure tests on a stocker vs a ported stocker vs a Log?????????????????
I would be interested in those tests.
If that was your price range I would pick the one with the lowest manifold pressure (probably the log but I dont know).

[Tony Hanna]

I can't help but wonder if there would be any benefit to a stepped tube log header over the traditional type. Something where the primary tubes are close to the same size cross section as the ports and the "plenum" tube starts at that size with cyl. 1 and increases in diameter as each primary joins in.
It seems to me a setup like that would really help velocity, but I have no idea what the effect on balance would be.

[MiniMopar]

I was thinking the same thing...or some kind of very-simple, non-equal-length, tubular header. I can see that as the RPMs go up, the exhaust flow in a log would be very chaotic making it difficult to setup a clean flow into the turbo exhaust housing. But again, it all comes down to what you are doing. For someone that is not running a huge turbo so that the car is still a decent street car, is a tubular header worth the effort/cost or will a log suffice? Someone with a T3 hot side and a stage 1 or 2 turbine probably isn't going to see much benefit with a fancy tubular header. Law of diminishing returns...no?

[turbovanman²]

I know running a log header spooled my stage 3 wheel better than the stocker but as for back to back tests, nada, :(

[GLHSKEN]

I cant give an example of someone using a log, small engine, and a big turbo because its just not happening.

I can... granted, the engine is a 2.5L, but the big turbo han no issues spooling. It actually needs to have the spool softened..

[cordes]

I can... granted, the engine is a 2.5L, but the big turbo han no issues spooling. It actually needs to have the spool softened..

perhaps his definition of a large turbo is different than the majority of people on this site?

[8valves]

perhaps his definition of a large turbo is different than the majority of people on this site?

Absolutely. And I know Ken is referencing to James' car, which does use a large turbo in comparison to the TM world, but that's a baby to the rest of the 4 cylinder world.

I'm glad to see people concentrating on powerband as well. Interesting in Warren's design is that it appears to change tube diameter at the merges. I've seen a lot of recent setups that have returned noteworthy gains by leaving the tube size constant as the merge happens... hello velocity! Now the "losses" from the length as people are assuming are overcome by the velocity gain at the collector.

Long tubes work, I tend to show people that very soon. Something somebody might want to search for is the test Full-Race did with their own ramhorn manifold, far and away a better design than any TM header/manifold save for a few custom jobs, compared to their "top-mount" which is around 24-26 IN length primaries. It spools FASTER than the short runner.

Also, you can help control the heat with thermal coatings and wraps. Moreover, your pressure wave has a chance to get a long ways away from the valve in a long tube design before the next valve event... large duration cams are now less of a worry in my mind.

Packaging is the #1 reason, and I still maintain that for a decent street car a nice cast log manifold with good transitions is the way to go, espescially for the price, but in all out a long tube design may prove to be king.

Hey Warren, what say you to 36" runner lengths! :eyebrows:

[BadAssPerformance]

How long are SMP's header runners? 4 feet?

[8valves]

How long are SMP's header runners? 4 feet?

By my slightly educated guess somewhere around 48 inches, so, yes!

[BadAssPerformance]

We both guessed the same it has to be right? :thumb:

[8valves]

We both guessed the same it has to be right? :thumb:

Well, it's not so much a guess. I mapped it out on my own car to get an idea since I have some interesting things going on myself that relate to this.

It's somewhere right around that length.

[BadAssPerformance]

I was going off foggy memory of seeing it in person. :)

[Warren Stramer]

Hey Warren, what say you to 36" runner lengths! :eyebrows:

Primaries measure 13.5"second stage pipes are 14", and final collector is 8". 35.5 overall.
I'm still running a small turbo, it is now my limiting Cork in the flow chain. It is a T3, .63 ar stg.III hot side with a TO4E 50 trim compressor. I could gain alot with an update but Traction is really becomming a problem so that is what ive been working on.
The biggest gain with the tube header was huge torque increase. second gear pins my ears back.

[thx138]

Is there any benefit to having a log header with a larger cross sectional area than the inlet to the turbine? I think I understand the reason for retaining the port sectional area into the header, but does the same reasoning (albeit backwares) hold true if one was squeezing the cross sectional area back down to the turbine inlet?

[8valves]

Primaries measure 13.5"second stage pipes are 14", and final collector is 8". 35.5 overall.
I'm still running a small turbo, it is now my limiting Cork in the flow chain. It is a T3, .63 ar stg.III hot side with a TO4E 50 trim compressor. I could gain alot with an update but Traction is really becomming a problem so that is what ive been working on.
The biggest gain with the tube header was huge torque increase. second gear pins my ears back.

Excellent news, I sent you a pm!

[Directconnection]

I just wanted to note that nobody in this thread is saying the log headers are superior to equal length headers by any means (except maybe the short one I flowed:evil: ). My flowtesting was to pin-point inefficiencies of the log manifolds. Comparing apples to apples for the most part in terms of flow potential and distribution (in which you can see how poor the OEM castings are on the #2 runner)

Garry M... I did a similar test on 1 piece and 2 piece intakes that I make a post about in another thread (induction). I ran two 1-piece intakes and two 2-piece intakes on the flowbench bolted to a stock g-head along with the lower halves flowed seperately. All 4 (actually 6) manifolds repeated to their respective styles as well.

Sorry for the hijacking.

[NeonShowCar]

I just wanted to note that nobody in this thread is saying the log headers are superior to equal length headers by any means (except maybe the short one I flowed:evil: ). My flowtesting was to pin-point inefficiencies of the log manifolds. Comparing apples to apples for the most part in terms of flow potential and distribution (in which you can see how poor the OEM castings are on the #2 runner)

Garry M... I did a similar test on 1 piece and 2 piece intakes that I make a post about in another thread (induction). I ran two 1-piece intakes and two 2-piece intakes on the flowbench bolted to a stock g-head along with the lower halves flowed seperately. All 4 (actually 6) manifolds repeated to their respective styles as well.

Sorry for the hijacking.

Highjack -- Nice Steve, where is this data. I've been outta this stuff for long time, alot has changed since I last played around with these things. Different times then back in 89'/early 90's. Technology has changed alot and I've learned alot more - plus designed a few intake manifold / exhaust manifolds in my day. :thumb: Always good to see everyone testing and getting data.

[Ondonti]

The log/stocker stuff was very interesting. You had tubular results on there too and I think that info is misleading to someone who just wants to say "my log header is the greatest" Etc.

[Directconnection]

Garry, I'll make a post tonight after work with the intake flow results, and start another with exhaust manifold test results from scratch for those who are interested.

Brent, the "equal" length header... not exactly equal length, but a good design. Big issue was the collector area that really hurt flow as the 4 primaries merged together tightly and had an issue at directing flow right at the turbine inlet flange. The tubes wer enot quite exactly square to the flange and some runners were flowing up against the backside of the flange, and one tube was aiming flow right out of the flange and blowing hard against the inclinded manometer which is facing the machine. That header was dusting the shop as boxes on shelves were flying places. This was when i was testing the runners by themselves bolted to a plate on the headstand and at 45" test pressure. Those log manifolds really make some serious noise at 28 and 45 especially.

[Warren Stramer]

Steve, You reminded me of a simple test I did with my header before I installed it, I forced compressed air into the inlet of each primary tube one tube at a time whith tissue paper taped near the inlet of companion cyl. tube hoping for a siphoning effect.......Eureka! blowing air into cyl tube #1 would create a vacuum on #4 Cyl. and vis versa, same effect on tube 2 and 3, also tried it with smoke.
Interesting thing was on the initial hit of compressed air there would be a milli second reverse pulse then immediate vacuum on companion cyl. primary. God only knows what happening in there in a running engine at differing RPMs, pretty dynamic thing to predict. Fluid Dynamics=WTF?!?!?!?:confused:

[puppet]

I can't help but wonder if there would be any benefit to a stepped tube log header over the traditional type. Something where the primary tubes are close to the same size cross section as the ports and the "plenum" tube starts at that size with cyl. 1 and increases in diameter as each primary joins in.
It seems to me a setup like that would really help velocity, but I have no idea what the effect on balance would be.
I know what your thinking ... a comparison to the intake side. Thing is that there aren't any pulses on the intake/plenum side, there are on the exhaust side. Adding a plenum here would be bad. The exhaust flow, with it's pulses, is like a dashed column of hot air. Smooth bends and consistent cross section are best.

I'm wondering why some of the fellas making the welded ell's haven't eliminated the (2) "Tees" yet. Welding (4) 90's (each with one longer leg) seems like it would produce better results.

I'd like to see some results from Steve (DC) with a turbo bolted to the exhaust mani during a flow test.

[Directconnection]

I know what your thinking ... a comparison to the intake side. Thing is that there aren't any pulses on the intake/plenum side, there are on the exhaust side.

There are pulses on the intake side and that's how they tune the intakes. It's from the pressure rise of when the intake valve slams shut.




I'm wondering why some of the fellas making the welded ell's haven't eliminated the (2) "Tees" yet. Welding (4) 90's (each with one longer leg) seems like it would produce better results.

That was my idea you just stole you bastage! ;) The T's are the problem with the welded el headers. Unless... you did like I did and did alot of massaging so to speak;)



I'd like to see some results from Steve (DC) with a turbo bolted to the exhaust mani during a flow test.

I have wanted to try that one for some time now, but I'd need to pump oil pressure to the center section and not sure if the test would be accurate enough. Can't imagine my flowbench would spool a turbo fast enough to make even 1psi since a turbo spins in excess of 100,000 rpms.

Besides... I think I am all flowbenched out for now:lol:

I'm going to post up the intake and exhaust manifold #s now in the proper sections (induction and exhaust)

[Gaboon]

I spent a minimum of 4 hours porting and re-working the log header I purchased. I would not have bolted it on as it was.


I'll soon find out if there is a performance gain.

[Directconnection]

be sure to let us know.

[shelbyvnt2]

I am giving this one a bump. It has been over 4 years now. Surely much has been learned in the last 4 years. I am about to begin my charger build and am very interested in what has been learned. I don't have the time or desire to reinvent the wheel. Any knowledge appreciated. Pat

[Force Fed Mopar]

I know that Shadow has made 500+ hp on a ported stocker :)

[trannybuster]

You realize they dont sell the tu manny any longer....I bought one becasue it does make a hybrid turbo setup easier...

[zin]

From everything I've seen, and I've held the cut-away in my hand, I'm pretty sure it should out ;,, perform a ported stocker out of the box, but, as usual, only if installed on an engine that can take advantage of it. Otherwise it will just be easier to install/remove/plumb the turbo.

I hope to add my personal results in the near future, if Life allows...

As a PS, it is a bit heavier than stock, but that means durability, and a true header could be made to be sequential, but given the cost to have a header built and still have no guaranteed results, well you can see why I bought one!

Well, that's my two cents anyway.

Mike

[trannybuster]

^^Yeah they certainly were made 'heavier' wernt they..I was happy with my ported stocker but lack of turbo options forced me into it, now Im going hybrid so wont even need it..sheesh.

---------- Post added at 11:26 PM ---------- Previous post was at 11:26 PM ----------

16valve hybrid

[zin]

^^Yeah they certainly were made 'heavier' wernt they..I was happy with my ported stocker but lack of turbo options forced me into it, now Im going hybrid so wont even need it..sheesh.

---------- Post added at 11:26 PM ---------- Previous post was at 11:26 PM ----------

16valve hybrid

I'll give you $100.00 for it! ;)

Mike

[Force Fed Mopar]

I wouldn't give $10 for one, honestly. It's nothing but a PITA in my experience.

[trannybuster]

Thought it was pretty easy ordeal. PITA is looking for obsolete Chrysler turbo parts and paying a mint for mostly left over garbage.

[shelbyvnt2]

Since most of this thread was about other headers besides the TU unit I was hoping some theories have been proven out. Any new info?

[Force Fed Mopar]

Thought it was pretty easy ordeal. PITA is looking for obsolete Chrysler turbo parts and paying a mint for mostly left over garbage.

It's not that hard to find parts. And define a mint ;) What most people on here call a mint, is chump change to the rest of the tuner world.