Originally Posted by psx_pat

Well,I change my header already.Only the secondary header pipe and exhaust pipe is 2". I don't use any catalytic converter. So,I'm thinking to change my secondary header pipe and exhaust pipe to 2.25" or 2.5", which one is better? Thanks.

Originally Posted by AF

A bigger diameter exhaust won't move where your car hits peak torque, rather you'll lose torque all over the board but gain top end horsepower.