Hi

Am i missing something but how is an aftermarket "performance up-pipe" better than the oem part? As far as headers,downpipe,centre-pipe and back-box are concerned i can see that a bigger diameter and straighter design would be better at speeding up gas flow but the oem up-pipe is as far as i can see just straight and the same width as the "perfomance" items.

Hoping to be enlightened.

PeteS

 

Performance uppipes are generally made of stainless steel so should flow better as the inside of the pipe is smooth as oppossed to the wrinkle finish on the cast item.

Really only worth replacing if you have a catted one as on some newage wrx, or if you are going for big bhp.