increasing catback piping

given an f22a1 with just the standard i/h/e plus a highflow cat, would there be any gain by using bigger piping? if so, what size should i go with?

yes bigger exhuast piping helps the engine breath better, but the largest i would run on a non-turbo car would be 2-1/4"

i'm guessing that is what he already has since he has exhaust listed. yea, if you go bigger than 2.25 then you would lose low end. no point in going bigger on n/a car.

oops, well i didnt mean exhaust, just a new muffler, with new piping... i had it replaced when i got the muffler. only thing is that its still stock size.