The only thing i have noticed is that the engine revs a bit more freely. i cant honestly say i have noticed any significant power gains but i think as the car is my daily i kind of get used to it if you know what i mean.
I would say bang it on as you've got it anyway, it certainly makes a great sound. If i could go back in time i don't think i would bother fitting one and stay standard. It was a lot of expense at the time for what i got back from it.
I think these sort of mods are best done in cojunction with other engine modifications to actually get more poiwer out of the car. As my engine is standard, i dont think it's done much to help really.
