what's the advantages/disadvantages between a 2 1/4" , 2 1/2" and 3" exhaust system ? going to be on a zetec turbo'd escort.
thanks

 

clearance issues spring to mind the bigger the bore.

 

may be I am being a Muppet but I though you got less back pressure with the larger bore, but it was louder and more awkward to route under the car and not get it too low or get bashed by the suspension over bumps!