I have a jdm b18c w/ a Mugen 4-1 header 2.5" outlet. I wanted to know if 2.5" exhaust piping will be good for a stock ITR motor? I'm planning on using a 2.5" Carsound Hi-flow cat w/ a Kteller 2.5" Piping and a ES Tuning Muffler. Would I lose power using a 2.5" piping or is 2.25" the ideal diameter? Thanks

 

2.5 is perfect until you boost.

 

So it's not gonna affect me negatively? I just want to run the best size since I'm going to change the whole exhaust using a Hi-flow w/ the ES tuning muffler.

 

Yea 2.5 is best.

 

Koo.. Thanks for ur opinion.