Currently have 2.5 exhaust, running 22-25 psi with GT30R equivilent turbo. Was going to go 3" ehaust, but since I will be venting a huge amount out of the wastegate, is the 3" needed?

Thanks.

the bigger the better in any case. I run a 3 to a cutout even with the ewg.

in theory, a 2.5" exhaust is capable of 450hp

if you've got an atmospheric dump EWG, you're bypassing most of your exhaust volume BEFORE the biggest restriction in your exhaust (the turbo itself)


2.5" should be fine. i'd be impressed if you made little if any power by switching to a 3" catback.

(you just need the DP to be at least the same size or larger than the exit on the turbine housing)