I need some opinions. I have a STOCK gsr that im about to boost. Hoping for mayb around 250whp Daily. What size piping should i get? 2.5" or 3" ?

 

i have 250hp and my stock ls/v turbo likes my 2.5 exhaust just fine. it all depends. I've heard that they've seen up to a 30hp difference with the two sizes, 2.5" being the lower....but that was on a built motor....you have a stock one.

 

im going 3 inch all the way back cat less on my stock stock stock gsr
tell me how your biuld goes what size turbo u got

 

Its a 57 Trim turbo. with a log manifold and 2.5" downpipe.

 

If your goal is 250whp with a 57trim, you could even go with a stock exhaust. The larger exhausts will just increase the spool time - and you'll need all you can get with that oversized turbo.

There is a huge difference when I open my 3" cutout, which otherwise runs through a stock Civic muffler. It actually cuts the amount of boost I can run in half due to the backpressure. 3" fits in most cases, so I'd suggest that route.

 

Yep I'd say go 3 inch. I just tunned my stock GSR with a T4 and I put down 315ph and 215tq at 11psi. You should make your goal with no problem. Becareful boosting is like a drug!