Exhausts Piping

i own a p10,
need to change the exhaust piping.
some guy at the muffler shop said 75.00 bucks for cat back 2.25.
should i get 2.25 or 2.5?

Originally posted by GtRider
i own a p10,
need to change the exhaust piping.
some guy at the muffler shop said 75.00 bucks for cat back 2.25.
should i get 2.25 or 2.5? For a NA SR20, 2.25" is considered by many as the maximum useful pipe diameter.

Originally posted by T4 Primera
For a NA SR20, 2.25" is considered by many as the maximum useful pipe diameter.

I concurr. Any larger and the exhaust gases slow down too much, thus hurting cylinder scavenging.