I was just wondering how all those harley guys do it with the straight pipes?I don't know about the rest of you but I personaly hate those bikes pulling up too my carin the summer. Even with my window up it hurts the ears. I understand wanting to be heard, but I think they take it too far

 

You get burnt valves on deceleration. When cold air is sucked into the exhuast and hits the valves.


Power output makes the decision of what exhuast you need. Enough power and the engine can overcome the loss of back pressure.