i am building a turbo car well its built but i wanna know if it is goin to make a power difference if i run a 3 in compared to a 2 1/2 exhaust im currently running a 2 1/2 .cause if so whats the ideal 3 in for a 94 honda civic hatchback

 

Depends on your target power output. Which would be.....?

 

depends on things.. my car for instance gains like 3whp going from a full 2.5" turbo back exhaust to a full 3".. not worth all the extra $$ and custom work IMO..

the more air you are moving though, the larger the exhaust you will need. if youve got a big ass turbo, youll 3" exhaust. if youve got a smaller turbo with quick spool, a 2.5" exhaust will be perfectly fine

 

its a 50 trim

 

3" straight flow exhaust (recommended when making 300whp+) or you can run a 2.5" straight flow exhaust with an e-cutout.

 

i was goin to invest in an electric cut out

 

Like they said it depends on your power goals, but imo 3" is the way to go. You may not make much power now, but you will probably want more later on and it will help.

 

i know with a car like what i have. it was texted with a full 2.5" exhaust turbo back and 3" turbo back. made like 3 more whp..

and that car is pushing 384whp with a turbo about the size of a gt2871r

 

If I were you, I'd go with 3" piping for future-proofing purposes alone.