Like Loco said. 2.25 should be sufficient enough, unless you have big plans, i.e. Turbo, supercharger. And you should be happy with the sound that makes, and it shouldnt be to raspy. Suriel had his resonator taken out and replaced the rest of the piping and it wasnt raspy at all.

2002 Focus ZX3, MTX-75: A good amount of mods 2003 SVT Focus ZX5, Getrag-6: FS Stressbar Best mod ever to my tour: A Beautiful passenger seat filler, that is my girl!!