As many of you saw on the main Cosworth thread, we did some testing with the plenum on Eagletangreen's 350Z, but had an issue with the plenum, and no good testing data came from that day.

So the next contestant up for Cosworth plenum testing, happened to be the infamous Philthy's G35. The car has been at our shop for a short list of minor to medium modifications that needed to be performed. All the big stuff, like engine, fuel, and EMS, was handled prior to the car's arrival.

Now lets get to the good stuff.

1) If you have upgraded fuel rails, and longer (non OEM) injectors, you will need one of these: Cosworth Plenum Spacer Kit This gives you the clearance needed to run upgraded fuel rails and larger/longer injectors.


2) A fair amount of assembly is required when you recieve the plenum. It is very easy work and requires basic tools, but is somewhat time consuming, and everything needs to be carefully trqed to spec. All fittings need to be installed, new hoses run, and in the case of the FI cars we do here, we tap for additional vaccum sources, as to avoid the use of vaccum T's.

3) Before the plenum is installed, and then after:



4) Here are a few more glamour shots:



Now for the results, with testing performed at low boost.
The overall peak power increase was a modest 13whp, but the change in power at 6600rpm is a huge 30whp. The Cosworth plenum definately flattens out the power curve towards redline, and results in a larger power gain as redline approaches.


We're working on a few other pieces, before shooting for more power, but just wanted to share the latest results.

Here are some more shots of Phil's car:

 

nice! :P
you're doing well with the D300 haha.... (the angled shot on the dyno is the best<3)

 

Interesting. Thanks for posting the reults.

 

Haha...arent you going to ask what the "red" button does?

 

I love the dual knock amp setup. Very nice car, and it's good to see some more quantifiable power gains from the Cosworth.

 

Nice tests...thanks for the comparo.

 

Very nice! Now for 20psi test!!!

 

I was wondering about that myself, what does it do?

 

hahaha.....what does it do? (now I'm scared......wtf does it do )

 

NO2???

 

neons

 

That test is ALL YOU man! Ready when you are!!

 

The hazards because of the panel for the knock amps. That's my guess.

 

Hazards??? It's a track car....doesnt need hazards...LOL.

 

stop being such a tease!!

 

Gorgeous car...

 

The gains noted are above the crawford set-up correct, or versus a stock plenum. I ask because I see the Crawford in the before photo, but I'm not sure when the baseline dyno was conducted, before or after the addition of the crawford.
I'd like to know as I am running the crawford now.
Thanks.

 

Sorry about that. Yes, the baseline was Crawford upper plenum. I am curious if the gains would have been even greater than a stock upper as the baseline.

The red button is for scramble boost.

 

haha nice... extra boost on demand is always good

 

scramble boost on the passenger side center console? weird.