A freind of mine who happens to be a former honda service dept. employee, suggested that if I put on a slip on exhaust that took the flapper out, that I would lose mid-range power but gains at the top of the rev range. I'm not too sure I buy that thoery since the "flapper" is non-existent in the racing arena. Your thoughts on this? Anyone have any real life dyno comparisons to bust this myth?