i was considering getting a Apexi gt exhaust system (almost 4 inch pipe). i was talking to my friend about it and he told me that that large of a pipe will reduce the backpresure to much a not give me as good on the low end side so i was wondering what u guys thought? oh i drive a 2000 Si

 

I think 4" is way to big!

 

For an all-motor Si, stick with 2.5" exhaust...

 

ya i think your right thankx for the help

 

see i told you