bowber wrote: ↑Tue Mar 16, 2021 2:19 pm
I've been watching Pirate Racings youtube channel, he's been doing a bit of testing on T7 exhausts. It looks like there is no point in changing the tail pipe for performance gains as the best only got a tiny extra bit of power and no overall gain.
I can't understand (or speak) German so I don't know the extent of his testing or if he had a go at optimising the fueling to suit each change but it's worth having a look.
Steve
Basic physics--by the time the gas has worked its way down to the muffler, and possibly been through a catalyst as well, cooled down to the extent that you could get away with half the pipe diameter and still maintain flow velocity, any change to restriction at the ass end will have virtually no effect on breathing/backpressure --except at peak revs and throttle--and who rides a T7 there ? Just because it sounds louder doesn't mean its doing any good--quite the opposite--cam profiles and timing coupled with backpressure are designed to give optimum efficiency throughout most of the operating range. The best you can hope for is a weight saving--any performance gain will largely be a placebo effect. However, a lot of people make a lot of money for systems that are simply straight through absorption designs that you could make yourself with a basic tube, end plates, some perf tube and wadding!