# Tubular vs log manifold testing!



## javierb14 (Jul 9, 2002)

another tubular vs log mani test shows how well they work. thanks enthalpy and mattback :thumbup: 



> We (Myself and Mattback) built a car for a customer that wanted 500whp. Specs are as follows:
> 
> CP Pistons 9.0:1 CR
> Stock Rods w/ ARP rod bolts
> ...


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## Binger (Aug 29, 2002)

is this an SE-R?


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## James (Apr 29, 2002)

That's nuts...


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## NotAnotherHonda (Aug 7, 2003)

why must you taunt us so?


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## chimmike (Oct 17, 2002)

that's RWD....that's Scott....infamous rwd sr20 tuner.

I think there should be equal length comparisons between brands...that'd be interesting.


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## javierb14 (Jul 9, 2002)

a tubular vs tubular would be interesting. it may be tough though, since for 2 its $2k+ in manifolds alone. also, in order to keep the variables constant, the manifolds would have to place the turbo, downpipe, and charge piping in the same location....which is highly unlikely.


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## mevans (Jun 5, 2004)

a 2.5" to 3" vs a full 3" downpipe comparison would be nice to see for a t3/4 turbo set up with a full 3" exhaust system after the downpipe.


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## xt_out (Jun 23, 2003)

^wtf? :dumbass:

nice test results! :thumbup:


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## mevans (Jun 5, 2004)

I was tired.


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## mevans (Jun 5, 2004)

Protech makes both 2.5" to 3" and full 3" downpipes. Some say a full 3" downpipe flows better and some say that 2.5" to 3" is better for a t3/4 hybrid. I bought the 2.5" to 3" downpipe and the stainless steel equal length turbo exhaust manifold from Protech for my turbo project, they makes beautiful functional pieces also.


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## mevans (Jun 5, 2004)

Protech makes both 2.5" to 3" and full 3" downpipes. Some say a full 3" downpipe flows better and some say that 2.5" to 3" is better for a t3/4 hybrid. I bought the 2.5" to 3" downpipe and the stainless steel equal length turbo exhaust manifold from Protech for my turbo project with a full 3" stainless exhaust system with a Jun titanium muffler, Protech make beautiful functional pieces also. BTW who's the dumbass?


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## mevans (Jun 5, 2004)

Protech makes both 2.5" to 3" and full 3" downpipes. Some say a full 3" downpipe flows better and some say that 2.5" to 3" is better for a t3/4 hybrid. I bought the 2.5" to 3" downpipe and the stainless steel equal length turbo exhaust manifold from Protech for my turbo project with a full 3" stainless exhaust system with a Jun titanium muffler, Protech makes beautiful functional pieces also. BTW who's the dumbass?


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## javierb14 (Jul 9, 2002)

whenever possible, fit the biggest dp/exhaust you can


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## Marc Z31 (Jul 25, 2004)

That is huge!

turbo diesel or supra?


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## mevans (Jun 5, 2004)

That's not what Bruce at Protech Fabrication says, he says for a SR20 turbo application a 2.5" downpipe to a 3" exhaust will flow the same as a 3" downpipe with a 3" exhaust. Anyone want to test this theory with a equal length manifold and a 3" exhaust system on a SR20 T3/4 hybrid system just switching between the two different size downpipes, 2.5" vs 3"?


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## pimpride (Mar 28, 2005)

If you want to buy me everything neccesary to do an SR20 swap, all turbo requirements, and everything needed to do the test, then sure.


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## thedaddies (Sep 29, 2003)

I still have a really hard time believing that crap. Something still seems fishy the more and more I read it.

I may have to buy/make a tubular manifold with good flow characteristics just to see the real difference. Since I wouldn't be biased towards one or the other. I would also be running the same AEM with either one. He could've added/removed timing and other things to affect the outcome.


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## chimmike (Oct 17, 2002)

well, you're also comparing their log vs. their tubular. If you look at it, it's not a true equal length manifold, nor is it a pulse converter design. 

And yes you do have to take into account diameter of the primaries, turbo used along with downpipe design and size, etc.


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## javierb14 (Jul 9, 2002)

Marc Z31 said:


> That is huge!
> 
> turbo diesel or supra?


its for a 1200whp+ supra


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## chimmike (Oct 17, 2002)

javierb14 said:


> its for a 1200whp+ supra


prolly too big for a turbo diesel LOL


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## javierb14 (Jul 9, 2002)

thedaddies said:


> I still have a really hard time believing that crap. Something still seems fishy the more and more I read it.
> 
> I may have to buy/make a tubular manifold with good flow characteristics just to see the real difference. Since I wouldn't be biased towards one or the other. I would also be running the same AEM with either one. He could've added/removed timing and other things to affect the outcome.


i dont know why people have a hard time believing that a well designed turbo manifold out performs a log/cast type manifold  we have run these type of tests on multiple setups....nissan (sr20det), honda (b18c), and volkswagens (1.8T). every single test supports the theory that a well designed manifold outperforms a log/cast type.

another one for your viewing pleasure 
http://forums.vwvortex.com/zerothread?id=1948604&page=1


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## thedaddies (Sep 29, 2003)

Don't get me wrong Full Race makes nice manifolds, questionably the best. Although for the "average" person at "mortal" power levels there is very little difference. Below 6000 rpms the difference was not very much either. Since most of our motors don't rev that high, due to head design not catering very well to that anyway. Doesn't make as much of a difference.

I'm probably going to wind up having someone make me an equal length, just to draw my own conclusions. I have to finish putting together mine own stuff first though.

Most non "sponsored" or "team" vehicles are not much more than a series of compromises. I think money is better spent elsewhere as well.


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## myoung (Apr 15, 2002)

javierb14 said:


> i dont know why people have a hard time believing that a well designed turbo manifold out performs a log/cast type manifold


I agree.... with all the test data over the years you'd think people would start to use a little common sense.... Nice job Javier :thumbup:


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## NotAnotherHonda (Aug 7, 2003)

Looks like some mods just love to delete peoples posts....................


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## myoung (Apr 15, 2002)

NotAnotherHonda said:


> Looks like some mods just love to delete peoples posts....................


I did......and only the off topic unessesary ones


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