Building the exhaust

[swhitty12]

Hi guys, been looking around at exhausts for the small 50cc engines and came across this guy on youtube:

https://m.youtube.com/user/russenmotor?

Any of the more experienced rider s and builders could tell me more about his setup, in particular the components he's used for the exhaust?

And perhaps how he gets a 50cc motor to go 90kmh!?!?!?

 

[GoreWound]

I think that his exhaust may be less of a factor than the fact that that engine produces about ten horses, and is mounted to a featherweight.
That said, that is a custom tuned exhaust, by the looks of things some amount of computer modeling went into it's design too.