I wanna get a custom exhaust made from the headers back any opinions on how big i should do the piping?

 

2.5"

you should check out ptuning.
Are you boosted.

What's your set up

 

yeah it'll be done by them for sure but no i plan on going turbo in the near future though right now just ihe.

 

I would still recomend the 2.5". I would call them and talk to Carlos.
He'll hook u up

 

iight thanks

 

2.5" for a n/a 1.5? you guys are crazy, it'll never build any velocity, car is going to feel limp, n/a should use no bigger then 2" it builds the velocity that produces horsepower & torque

now for after a turbo, 2.5" will be fine to about 300hp give or take on the exact set up, you could get away with 2.25" on a mild turbo set up that doesn't see sustained high rpm, heavy throttle use