i heard someone once say that square piping would make the exhaust louder. dont know if its true or not but... now for the 2.5 inch piping you talkin about, is that gonna be to big? cus we dont want to hear you come back and say "sounds great but i lost torque, yada yada yada." i dont think id go bigger than 2 inch. but then again its all about what your after, SHOW or GO! i cant even hear my exhaust right now cus i got the silencers in hahaha! but even with the silencers in she makes a nice lil purr at certain rpms and on dpownshifts, like a quiet deep tone thats real sexy lol. well let us know how it goes.