Just wondering what type of exhaust to get. I have an all-motor set-up (1.8L GSR, with 12:1 compression, Port Flow GSR head,...), I have a custom header with a 2.5" collector. The question would be should I get 2.5" piping all the way through or 2.25" piping. Also should I run a resonator? And should I run a straight pipe, carsound cat or what? And the last but not least is what is a good exhaust to get, sound and power wise?

 

2.5" all the way through since you have a 2.5 collector. YES!!! Run a resonator, just get a strait through desgined resonator so that your exhaust flow isn't hurt.
Strait through cat! The test pipe should only be for the track for two reasons, 1. You will get a $3,000 fine for not running the cat and 2. The exhaust is going to come out dirty as hell and stain your car. Good exhaust is the Apexi N1, they are getting cheap right now cause they want to come out with another line.

 

Thanks...greatly appreciated