Originally Posted by mn stryker
Stupid question but don't you lose so much back pressure that it can harm your engine?
Loss of backpressure in general will never hurt your engine. The increased exhaust flow WILL pull more air in causing a leaner mixture, even with stock air intake setup, which will cause a loss of low to mid range torque for sure. To offset that you have to install a fuel programmer to bring mixture back to optimum levels. The stock exhaust is more than long enough to keep you from damaging the exhaust valves. Removing the cat entirely will not produce a pleasing sound in my opinion. If you leave it in and just "gut it" (pain in the arse BTW) then it serves as an expansion chamber. The exhaust pulses mix in that chamber with the backflow exhaust and cause a nice mellow rumble. The key to removing your baffles is to disturb the inner plate that the baffle is welded to as little as possible. That plate serves as a torque cone, reducing the diameter and increasing flow (velocity) while maintaining just enough backpressure to be a fairly well tuned exhaust. I am running stock exhaust, gutted cat, no baffles, Cobra autotuner, cobra intake, and the bike sounds great, deep rumble, no popping or backfiring, pulls harder at any rpm than a stock bike and HP is plenty for the bike. Now after saying all that, I do think the best exhaust note is obtained with Vance & Hines Big Radius 2 into 2 with monster baffles but my setup is so close it isn't worth the extra 600 bucks.