check out this exhaust manifold, GT35R powered alltrac by speed-source Options

[jgreening]

Ah yes, the infamous post by RickyB from 2004 where he essentially argues that the stock manifold is not a performance limitation.

Perhaps you missed this reply (which was left unanswered) from a high hp 3sgte builder in the same thread:

What I noticed was left out of this post for some reason is a description and explanation of which setup will yield the greater volumetric efficiency... or is performance defined as turbo response? Or how about some details and explaination into determining what kind of pressure differential you want between your intake/exhaust... factoring in camshaft profiles and cam timing. Maybe your leaving out some details?? No??

To say that a decent shorty manifold will spool a turbo faster.. well... i thought that was common knowledge.

But for you to just go ahead and make a post saying that tubular style exhaust manifolds will yield "less performance" without far more supporting evidence here is pretty damn... well... ignorant.

There is a lot more to consider in engine performance and turbocharger system efficiency other than "short = hot = spools faster = better"

Based on what you say in your last paragraph... lets take it as vague as you say it.... do you think that if someone was trying to build a 1000hp 2.2L engine, they should use the stock exhaust manifold ported and coated?

BTW I am not trying to argue with you, I am just trying to get your educated feedback for more detailed explanation. I am still in the middle of my hands on R&D of exhaust manifold design so I am not prepared for a dispute with someone I am assuming must have done some R&D on this.

Or, perhaps you missed this post of of Ricky's from 2006:

I'm getting very close to my original goal of making a safe, daily-driving 350rwhp at 15-16psi on 91 octane. I have one more trick in mind that I think will get me there. I am going to ditch the stock exhaust manifold and have Hoover at Turbohoses build me a tubular exhaust manifold.

I have argued many times against poorly made tubular manifolds, but I am willing to try a well made one with good ceramic coating to see what it buys.

(emphasis added)

check it

I think Ricky's opinions have evolved some - perhaps yours should too.

[CilverSeliST205]

This is a very informative thread, I never ran across these mr2oc threads!

[playr158]

I think Ricky's opinions have evolved some - perhaps yours should too.

my opinion is that manifolds like full-race are good have proven gains, that manifold however doesn't appear to be on the level of full race....unless you can prove that manifolds performance, it looks well crafted but not anything remarkable

[Punisher]

I think that manifold was done to fit that turbo more than anything.

[jgreening]

I think that manifold was done to fit that turbo more than anything.

Correct. The alltrac has a very thick aftermarket radiator that did not allow placement of the turbo in front. My point of this thread was that the manifold is a very nice piece of craftsmanship.

[Punisher]

I think that manifold was done to fit that turbo more than anything.

Correct. The alltrac has a very thick aftermarket radiator that did not allow placement of the turbo in front. My point of this thread was that the manifold is a very nice piece of craftsmanship.

I'd have to agree.. there are some pretty tight spots to weld on there

[lagos]

I think that manifold was done to fit that turbo more than anything.

Correct. The alltrac has a very thick aftermarket radiator that did not allow placement of the turbo in front. My point of this thread was that the manifold is a very nice piece of craftsmanship.

besides just the radiator, there is a lot less engine bay room in the 5th gen vs the 6th gen. everything was so cramped on my 5th gen clip. you had to remove the radiator just to do anything, and even then there wasn't much room to work with.

[azian_advanced]

another similar exhaust manifold
iono, just found this on the net, it's worth taking a look at.

[playr158]

thats your standard looking E-bay POS..
the fall apart pretty quick

[Bigmeanbulldog55]

I can't see an up-pipe adding that much to a turbo. You would have to be maxing out your turbo and running pretty high boost for one of those to really be effective. At least thats what it seems like to me. I've seen some really high hp numbers made from stock manifolds or log style. That equal length is really pretty though.

[x_itchy_b_x]

it has do do with the pulses of exhaust gas hitting the turbine with an equal pause between each pulse. it just helps low end spool really or even just a little midrange.

[tufy]

manifold is very important. its not only shape thinkness is important also. each pipe should be same lenght. we had so many proplems when bulding my cuscom maniflod. its 48mm thick. good for my turbo and set up. we removed radiotor fans to have space between engine and radiator.



This post has been edited by tufy: Feb 28, 2007 - 5:55 AM