I tried the pipe at the track Sunday. I ran it on my daily driver with a mostly stock 69cc China girl.
First mounted directly to header pipe, ran smoother but no noticable power gain.
Neil suggested a longer header.
I used a 12" high heat 3/4 id. hose for next test.
With length at 13 1/2" total mounted down the center between crank. Good tork and speed with this setup.
Tried it on one of the race bikes and it worked good.
I am going to use this pipe on my daily driver from now on.
I recomend others try this pipe it sounds good and it's not loud.