Well, we don't really have a forum to post this so I'll put it here until we do.

The question: Why don't header and exhaust manufacturers put baffles in the exhaust system (other than mufflers)?

I was thinking about this and we use baffles in HVA/C system all the time to control the flow of air around turns. The reasoning behind this is to keep the air moving equally around turns. If you do not use baffles the air creates vertices as it tries to turn. These vertices slow the air down restricting air flow and produce higher static pressure. The baffles in the muffler are to control the noise levels exiting the muffle, not for airflow control. If manufacturers did this theoretically it would product higher hp ratings from the exhaust system. One thing I do see as a problem by doing this is lower backflow pressure. So what does everyone think/know in regards to this design?

 

I think essentially because there arn't many bends in most systems. I think also that (I know on my car) the air vents are more rectangular or square in shape to begin with (my car is a 1979 MY though). So baffles are needed to direct flow better, but in exhaust pipe I think the baffels would cause restriction in themselves (assuming mandrel bends) by causing the diameter of the pipe to decrease.