Simon, the H-pipe will give more of a bass tone to the exhaust with some pops and bangs on the over run. The X-pipe is much more raspy and higher pitched, but will give more pops and bangs. I prefer the lower tone to the rasp, loudness-wise I'd say it's about the same having had some time to measure against Benny's car in Le Mans. I changed the manifolds to Euro spec decat manifolds and have Larini 200 cell sports cats. I should be at the next Ace meeting so maybe you can hear it then, or feel free to pop over and hear it if you're in the area.
FWIW I rarely switch mine out of Sport mode, even when in my road. The car can be driven at residential road speeds on a light throttle without making too much noise, but it's definitely louder in stealth mode than the modified GS boxes as sported by Benny & Matt's cars.
FWIW I rarely switch mine out of Sport mode, even when in my road. The car can be driven at residential road speeds on a light throttle without making too much noise, but it's definitely louder in stealth mode than the modified GS boxes as sported by Benny & Matt's cars.