Thread: GTiR vs Avenir/Blue Bird Dyno Comparisons?

I've tried to find a decent direct comparison but can't seem to find anything. Anyone have any power numbers from simply swapping from Avenir/BlueBird manifold to a GTiR one?

Finally got around to testing it!
http://www.sr20-forum.com/turbo/70757-t2-turbo-manifold-testing-avenir-vs-gtir-vs-asp-vet-manifold.html

This will be interesting.

Every once in a while I see some vague reference to the W10/W11 Avenir manifold being better designed than the GTiR but the GtiR having better flow. I still can't find anything that goes into more detail, so a comparison will be great.

I also wonder about any advantages of the Avenir over the Bluebird.

I'll tell you this much, the GTiR is the most diffucult to install! That damn bottom nut is enough to make a grown man cry, even with a Gearwrench.

C

Avenir and Bluebird turbos flow about the same, the only difference between the two is the turbo flange angle. Avenir manifolds should allow up to 2.5" turbo outlets, while Bluebird is closer to the block thus 2.25" is probably the max you can fit without modifications.

GTiR lets you fit 2.5" comp housings easily, 3" with some grinding. GTiR locates the turbo to the passenger side more, it also sits the turbo lower then Avenir/Bluebird. GTiR manifold clears the cross member mount better, but also sits closer to the alternator and AC. GTiR manifolds supposedly flow a lot better, but I'm curious on how much better.

I personally like installing Avenir manifold more because you can easily reach all bolts that go to the head. GTiR has one bolt that is painfully hard to get to even with a ratchet wrench. Avenir manifold has another annoyance too, bolting up one of the Jpipe to downpipe bolts is a royal pita to get to. GTiR manifold is much better because it locates the jpipe completely past the cross member.