Hmmmm. Other than complaints of a long wait, I havn't seen anything yet.
At least not flames or hate.

You won't see me say anything bad about them even if they are competition. Competition is normal, expected and a good motivator!

 

Kool...

 

Tonight we tested the Cosworth intake plenum on an '05 350z with Turbonetics kit. The car was setup with a plenum spacer before, so the comparison here is Plenum Spacer vs Cosworth Plenum. The test was performed at 8psi and ~340whp DD.

When switching from the plenum spacer to the cosworth manifold, we found a small loss in midrange power, and gains of 5-10whp starting at ~5200rpm. The cosworth gains were the greatest as we approached redline, set at 6500rpm on this stock-motor Z. Look for the dynos tomorrow.

 

maybe also consider that the car wasnt tuned for the cosworth intake manifold. either way, i am very interested to see the results.

 

hmm, sounds kinda gimmicky for the price if you're dropping HP midrange and gaining 10hp on the top end.

but at least it looks better than the stock plenum....................

 

We will be dynoing a turbo car next week with a built motor and cylinder head.

 

before and after i presume?

 

Of course.

 

Future dyno graphs could prove my wrong, but heres my take on it.

It is a much improved design over stock, however to get to that improved design the runners appear to be a little longer than stock. i think the power gain is due to the improved design, and is perfect for most cars.

However, due to the increased runner length and lack of any significant gain of, if any at all, displacement, its not going to be a high RPM performer.

I could be proven wrong shortly with more dyno graphs coming out, but I bet this thing isnt going to be the peak RPM performer that some people were hoping for. It just doesnt look like the right recipe for that.

 

Charles,

At what rpm is your billet manifold designed to operate most effectively?

 

5-10 horsepower over the performance of a OEM plenum and spacer is much better than comparing it to a stock OEM plenum (without the spacer). Don't forget that it's 5-10 over the improvements already made by the spacer.

This is the first crack at this plenum. I think that's a good indication for the future of the Cosworth plenum.

 

IMO, it's just another intake manifold.

But hey, it's Cosworth, so the $1000 is well spent, right?

 

Looks good. I'm not getting into the dyno arguements. I think its gonna be the "Awe!" factor when I pop my hood.

 

Exactly ...+1000000000

 

the helmholtz tuning theory suggests best harmonics for performance at about 9000rpm with the design we put in it. obviously ahead of its time, mostly is why we havent really touched it since finishing the first, its concept is sort of waiting for the rest of the VQ35DE world to catch up in terms of camshafts and turbo size. Based on the single dyno test we did with it on a NA car, only reving to 7200 or so IIRC, it was looking like it was going for that 9000ish target... as it had a couple horse power loss until about 7000 where it matched the before and who knows how it would have climbed or not climbed above that. On a boosted car, it might provide gains at a much lower RPM, but only one way to find out. The manifold is in the hands of the guys at sound performance. We gave it to them. If they tell me that it worked out well for them, we will do something with it again.

 

Are the velocity stacks adjustable (and if they are wouldnt this have an effect on the powerband?)? I cant wait to see the dyno plot comparing this to the spacer. Also did the car run more lean after you installed the cosworth manifold (both the stock car and the boosted car)?


I'm on the fence with this. My car has a fair amount of breathing mods (incl. cams and a 5/16 spacer) and I would love more topend power with my setup. I'm trying to justify the cost. This may be what I need to break 265whp on my 5AT.

 

you're such a ricer robert!

 

Lets just see how this folds out with more dyno's. not just one! i am sure in N/a form youll see the same levels a couple loss here but a couple gain their. i am sure this thing performs better under fi cars, than the spacer might, time will tell tho. either way i am in already so their is no turning back.

 

Quick lesson here though...

Ricer: (Rice-er) Noun; One who purchases cheap products for one's car and product doesn't improve any cosmetics or performance of said car. (I just bought a new AutoZone airfilter with intake tube wrapped in a CF sticker for $50. I know... I'm a ricer. )

Baller: (Ball-er) Noun; One who purchases overprice products for one's car and product doesn't improve cosmetics or performance of said car anymore than same quaility less expensive products. (I just bought the Cosworth Intake Plenum with real CF end caps for $1000! Don't hate me cause I'm a baller! )

 

OOOOOOh.. Rob is baller.. I guess im baller too.. Thanks for clarifying..