Engine Trix pipe 
et-pipe

This is the best overall performance from a Go-Ped pipe. It is an excellent choice, but the JetPro pipe is now a serious competitor. This item mounts very solidly and is wrapped around the rear of the motor for a balanced look and feel.
At $179.99 it is one of the more expensive pipes, but you do get what you pay for.
This pipe does require use of the handle pole extension.