Definitely 3".. that's what I'm upgrading to for my current build.upgrade it to 3 inch, more flow, less restriction, but i would also tune it as well so u can benifit more from it
Nope!im pretty sure i have a 2.25 right now connected to a rs*r ex mag. would that work or would i have to upgrade to a turbo muffler? and wouldnt 3" piping be loud as s**t?
yep once your runnin a turbo, the car actually gets quieter...Nope!
I have a 3" exhaust all the way back with no cat (but with a resonator and a fartcan) and it sounds great!