Just had a quick look at the rules & it says that exhausts can be modified, standard monster cans ground out before anything else. Buying an off the shelf high level system costs in excess of £500, just trying to help our lads & lasses out as even racing on the cheap is expensive.
(Exhaust pipes and mufflers can be modified or changed)
Chris
[Edited on 10-12-2004 by chris.p]