Thread: T2 Turbo Manifold Testing: Avenir vs GTiR vs ASP VET Manifold

Ever since posting this thread, I've been curious about how much power GTiR manifolds make over Avenir's. Also, I was curious to see a comparison to a much better flowing manifold: ASP tubular VET Manifold.

Top to bottom: ASP VET, GTiR, Avenir



Top to bottom: ASP VET, Avenir, GTiR



Avenir Manifold
Installed:


Head view:


Real flow restriction:



GTiR Manifold
Installed:


Head view:


Major flow restrictions:




Found it much more painful to fit a 3" intake on the GTiR manifold, it hits the trans.



ASP VET Manifold
Installed:


Head View:


No real flow restrictions, very good merge collector compared to the other two manifolds too.




Finally the results... keep in mind these are done using Virtual Dyno on same stretch of road.
Setup: Roller Rocker, GT2860RS "Disco Potato", 3" Exhaust


I'm really surprised that GTiR manifold was not only more painful to install, more painful to attach a 3" intake to (or have a 3" comp housing), but also didn't make any real power over the Avenir.

Perhaps what surprised me the most is the fact that a much better designed ASP manifold didn't make all that much power over the other two. I think this is because of very low overlap stock Roller Rocker cams, thus T2 turbo restrictions still supersede the manifold restrictions.

Good peice of work. Thanks for putting n the work

Wanted to cross post Charle's post from G20.net, which explains on why ASP didn't make all that much more power over the other two. Simply put exhaust to intake pressure ratio, the lower it is (by having low boost), the less power is lost due to inefficient manifold designs.

Hey Vadim,

Very surprising results! The Avenir makes more power than the GTI-R until 6500rpm?! Whaa?!

What A/R do you have for the turbine housing on the Disco?

p.s. I plan on picking up the water lines this week lol

p.p.s 8psi? wtf? turn up the boost! 12psi at least. Don't be afraid of the boost. I have a good friend here in KC who ran a 2860 on a stock roller for a couple years @ 17psi daily and 22psi w/'race' gas. Engine still going strong when he sold it.

-G

Awesome job testing! I suspect that a big reason your not seeing larger differences is, well, because a set up is only good as its worst restriction ... if you had a better flowing exhaust elbow I think there would have been more variances

Very cool man... Thanks for doing all the work to get this comparison. This just shows you that keeping it cheap and simple with smaller setups is perfectly fine.

As always - awesome info !
Respect!

GTiR had a fatter power band though, I wouldn't read into the graphs that much though, real dyno would show much more realistic numbers. Virtual dyno is good for giving you a side by side comparison mainly for peak numbers.

I had a 5 psi wastegate on this this thing, plan was to do boost by gear with NEMU, hence low wastegate PSI. Since I'm done with this car, no point in cranking up.



Going divorced would yield even more gains, but the elbow is not THAT bad. Plenty of people run 300whp on it still.



Yup that's what I noticed. KISS for simple setups.

Great test, but it looks like the VET manifold was quite a bit richer. May be the reason for less power?

Could be, I didn't monkey with the tune between the manifold runs because I wanted to have one less variable.