[BevanWright]

750HP I have a variety of mufflers in my sidepipe. From the collecter back there is a louver tube inside the sidepipe wrapped in a green sound deadening material. (it was from the factory who make a lot of mufflers for HSV Commodores in NZ) It is better at sound deadening than the standard packing, and resists heat better. I believe the stainless will survive but does not reduce noise as much. At the end of that section my car has a supertrap muffler, which allows you to 'tune' the noise by removing baffles, you reduce the level of noise. I dont know how bad these are on power, but, I had to do this as I was over 100db and we are only allowed to be 95 (measured from right angles from the side of the race track under full acceleration.

The best noise I have had was when at Ohakea airbase their was no noise restriction and I ran the car with open side pipes, man it was loud - but sounded awesome at full revs. (like a McLaren race car)

(I cant work out how to add a picture here - but if you look at my picture in the aerodynamic aids thread you will see my sidepipes.)