IMO, Fujitsubo makes some of the best mufflers on the market. However, they tend to play to the safer and quieter side, which may not be to everyone's tastes. A test in Revspeed showed that the Fujitsubo exhaust manifold for one car, for example, was in the lower-end of the hp gain scale compared to other exhaust manifolds, though I'll wager that it also produced better low-end than the others.

Paul Hansen

 

Best exhaust is an open dump tube going straight out to atmosphere. When you want quiet, just route the exhaust gasses back through the stock exhaust with an electronic cutout:

 

Yeah, lets just hope your good at spoting cops, and can cut it out before they hear it. Kinda hard to say it wasn't you when they heard ya a mile away, heard ya drive past, and now its quiet?