uavflyer76,

If you want to tune your tuned pipe system, put the pipe on the uncut header and tach your engine at full throttle, pull the pipe, cut 1/4" of header (with the silicone coupler attached to the pipe), run the engine and tach it again looking for an in crease in RPM. Repeat this until you get a drop in RPM. Then take the last piece of material you cut off the pipe, insert it into the silicone coupler pushing it all the way to the pipe. The reason for this is to lengthen the header that 1/4" when you reassemble it.

Hogflyer