Well i know nothing about the ss50, but a while back i saw this page: http://beadec1.ea.bs.dlr.de/Airfoils/tpipedes.htm and decided to try and build my own tuned pipe. it works great. all you really need is some metal (a few pieces of steel tube, some sheet metal), an oxy-acetylene torch, and a tiny bit of welding knowledge (or if you have one you can use a mig or tig welder (i think stick would blow through too easy on the thin metal..)). go ahead and try it from that page, or if you like you can check your library to see if they have a book on two strokes by Gordon Blair. its got great stuff for pipe design.