Originally Posted by uptown
Help a dense yank out here - so the reason for the elaborate exhausts are to emulate the first cafe racers - no performance boost or any other practical reason? I'm a geek - I have to know these things or I loose my membership card
A well-designed header system can reduce backpressure and increase flow-through. Usually that'll give you something, mostly at the top end. But the design has to have the tubes matched in length pretty well to be very effective, that's why sometimes they seem overly convoluted. But not every convoluted system has necessarily been so carefully designed...