Had a nice few little blasts with my mates cars yesterday. firstly my mates 2.5 Z4, from 30+ there was nothing in it until over legal speedds, only gear changes were giving me teh minor advantage, and secondly my mates chipped TTR, again peanuts in it until silly speeds, although i didnt manage to have a side by side comparison. Quite happy with that considering its still totally standrd bar cat back exhaust!