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
ARP Headstuds
Greddy Headgasket
HKS 264 Step 2's
RAS
Greddy valvesprings
Greddy Intake Manifold
Garrett GT3040R Turbo
ROM tune - Z32 MAF, 96# injectors
JGS Tools Log Manifold
HKS Intercooler

When we took it to the dyno for tuning all we could get out of the car at the wastegate pressure of 12.8 psi (0.9 kg/cm^2) was 300whp. I tried different AFR's and timing values but they yeilded no change. The setup simply would not make more than 300whp @ 12.8 psi. This was a problem becasue I knew that we werent going to get to 500whp without running stupid boost...which i didnt want to do. So after alot of head scratching and a few beers to help cope with the disappointment Matt and I compiled a list of everything that was different between this car and my car when it was running a nearly identical setup and making 340hp @ 10 psi.

This is what we came up with:

1) Log manifold vs. Full Race manifold.

2) ROM tune with MAF vs. Haltech on MAP.

At which point we looked across the garage to my car which is currently out of commission and decided we needed to try swapping manifolds. A call to the customer to discuss the situation...and he agreed it was the correct course of action. So the test was on!!

Matt and I worked dilligently friday night after work to get the manifold swapped over. We used my old downpipe and hot pipe of my car. These pieces were nearly identical to the downpipe and hotpipe that were on with the log...just slightly different fitments. We got it up and running, celebrated at Hooters for a late dinner...then headed off to the dyno on saturday morning. I was expeciting to see gains but we were unsure of how much. On satuday morning we ran the car at wastegate pressure (12.8 psi) and after a bit of tuning to get the new setup dialed in we saw the following gains:




All i can say is WOW...60whp and 35ft-lbs. Spoolup was almost identical with the Full Race hitting maybe 100 rpm later. I was completely floored by the results of this test. I was expecting 30-40hp maybe...but 60hp. I was totally shocked.

I think this also disproves the myth that MAF sensors are a restriction. this car made exactly what my setup made at 12 psi with a MAP sensor based system.

The truth of the matter is the flow properties of the LOG manifold are terrible. The flow from 1,2 and 3,4 directly oppose each other then are forced to do a hard 90 deg turn to enter the turbine housing. A basic understanding of fluid dynamics will tell you this is terrible for flow. The smooth transistions of the full race manifold make all the difference allowing the car to make more power even during spoolup!!

Thumbs up to the guys at Full Race for making such a quality product!!

Oh...and the car did 507whp @ 25 psi later that day!!

 

good stuff.

platinum

 

Did you modify the tune at all? Or did you simply swap the manifolds and that is all? Extremely impressive, hopefully Full-Race can explain the engineering behind why their manifold creates so much more power. Is it a simple exhaust manifold backpressure issue? More power is made by less restriction before the turbo?

Full-Race: Could you expect less gains on a car with less cam overlap?

 

i had to change a few parts of the fuel maps...but the timing was the same!

 

Damn! Full-Race > All others

 

Wow, very impressive, full-race makes some amazing parts.

 

thanks for taking the time to do this test scott!

the power comes from the fact that with a long runner merge collector manifold, more energy from the combustion process is able to reach the turbine. There is simply less losses, and a cleaner more detonation free charge from less reversion yields a more power combustion event with high gas velocity in the runners.

hondaddict-- you are correct, if the car has very small cams, the gains will not be as dramatic. There will be gains, but the smaller the cams, the less the flow will matter as the valve becomes the restriction.


Modified by Full-Race Geoff at 11:48 AM 11/15/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Full-Race Geoff &raquo;</TD></TR><TR><TD CLASS="quote">hondaddict-- you are correct, if the car has very small cams, the gains will not be as dramatic.</TD></TR></TABLE>

agreed!! with stock cams on the SR (240 duration 9.2mm lift) the log manifold performs slightly better than it did in this test. however the addition of 264 deg 10.5mm cams with a LOT mroe overlap produced no power gains due to excessive turbo manifold backpressure.

 

Nice post, how much longer before you get you car back up and running?

 

hahaha...this car got me all excited again.

rebuild process begins this week!!

 

Nice test Scott.

 

Nice test, and props for using OEM ECU. Which software are you using, if you don't mind me asking?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Enthalpy &raquo;</TD></TR><TR><TD CLASS="quote">hahaha...this car got me all excited again.

rebuild process begins this week!!</TD></TR></TABLE>

About time you slacker. Glad you got those injector gremlins covered.

 

Damn. Let me pick my jaw up off the floor. Very nice!

 

Damn ... I hope the customer decided to keep this exhaust manifold? The results look great Scott. Nice running into you again Thursday night.

 

glad u got that thing situated scott. last week i thought your gonna unstrap it from the dyno and drive it into the wall. nice work!

 

Glad to see that got worked out... I could tell you were getting frustrated with it on wednesday when I was up there.... I myself was even kinda wondering why the numbers werent there... It looked to have all the makings for a big power car, just without the big power... Glad to see you finally got her there though!!!

 

my full race manifold is my secret around here..

do the top mounts help that much more over the prostreet model i have?

 

good stuff!