Quote Originally Posted by SpencerPJ View Post
I have them with my cobra 626 exhaust. IMO, I think they were designed to add a slight backpressure to some of the aftermarket exhaust systems, but the stock exhaust already has restrictions so if you add loopz, it might have negative results.
There are no negative results. These are on literally thousands of bikes (about half with stock exhaust). They have been made since 2002.
Everyone we have ever talked to has been extremely happy. They will eliminate the droan. You will notice the difference in throttle response even though there is only about 5% increase in torque and HP. The sound is tremendously better when using after market exhaust.