I have a T3 turbo and my downpipe is 2 1/2 inch with a tanabe cat-back exhaust stock cat. My question is im boostin at about 2300rpms and i was wondering if a 3inch exhaust system would be benificial for me ? i'm going upgrade the cat for sure but is 3 inch gonna help me more ? the max i ever look at boostin is 15-17 psi. TIA

 

anyone ? i plan on going to the muffler shop tomorrow....so any advice will be appreciated

 

ofcourse it would help, less restriction.