haha thank you, as a matter of fact, I dont use that engine at all anymore. Both pipes were about the same speed. The Technigas has a bit more low end, while the biturbo had a little more top end. The biturbo pipe, was all junk, but we welded patches in it, and made it curve up, like a real motorcycle pipe. It was loud, in a good way lol. The shocks are stock, but painted. Where's the butterfly screw your referring to?
btw, stick around, in about a month, I will get some new pics of the bike...its going to be COMPLETELY re-done...