Quote Originally Posted by mudski View Post
Funny about this. Everyone says that, but when I went from stock to 3inch Redback, boost and EGT's did not change at all. As for back pressure. You don't see race cars, even turbo charged one using mufflers, the quicker the gas gets out of the exhaust the better the engine will flow. IMO, back pressure is an old wifes tale.
Back pressure is necessary for sure. Not in the form of mufflers but say for example if you have no exhaust at all your car will run like absolute crap