Exhaust Exhaust sizing

[BikeProblems]

Hi there,

I was wondering if anyone knew if the diameter and the length of the exhaust pipe would affect performance of the engine. Also does having an expansion chamber help or would it be better to have more of a straight through pipe, and somehow work out back-pressure problems/issues.

Thanks
BikeProblems

 

[retromike3]

expansion chambers work

When I put one on my bike I noted a huge difference. It effectively doubled my performance. The only thing that I found that was negative was that the power band was much more narrow. I have to modify the size of the pipe to get the power at a different RPM.

mike

 

[spad4me]

Yes the length from the exhaust port to the first bell will affect the performance of a tuned pipe.
Tuned pipe is the key word at resonance the sound and pressure waves inside the chamber will act like a supercharger.

http://en.wikipedia.org/wiki/File:Arbeitsweise_Zweitakt.gif

Large diameter inlet pipe, small or muffled output pipe. A stinger looking pipe on the end of rhe chamber.