Quote Originally Posted by Lucas_R View Post
This is the one i got: AdrenalinR - Performance products - Resonators - Louvre Baffle

Their standard lengths were all too long, so i spoke to them and asked about the possibility of ordering a shorter version. They said "no problem, we actually make the mufflers so we can make them any length you like". So i measured up under the car and figured around a 9-10inch resonator would be about right. So i ordered a 10inch long version. The diameter is 3inch so it matches the pipework of my dump pipe.

As for trade off's, you might lose a few hp due to the slight restriction, but it will be minimal anyway and didnt bother me. FWIW the car feels no different to before, apart from being quieter and sounding nicer.
And by the looks of things it couldn't have been any longer if you tried. I'm guessing all resonators are going to cause some loss... but if they're using them on race cars it can't be much otherwise they wouldn't put them on.

OK I think I've convinced myself