RE: Club Enya
Volume, stinger size, port timing all play a role. The trick is finding the pipe length/volume that works best with the timing of the engine. Being that the stock muffler is so small, I figured there would have to be power gains if the muffler size was increased. My experiments technically were/aren't "tuned", as the Jett muffler gave the same results as open faced. I have a .25-.35 Jett muffler now too that I will try on this engine, and my Super Tigre S29. It's tuned for 17,000-20,000 where the .46 sized Jettstream is tuned for 15,000-17,000rpm.