i have the hot bodies gp shorty . i loose some tourqe down low but it comes in hot on the top. i dynoed my 06 cbr 600rr and got 107 hp and 46 or 47 cant remember fpt. i have a commander so that helps alot with t=loosing in the low end. my buddy has same bike same color and year, he has a yoshi carbon slip on no commander. if we go from a roll i destroy him by like 5 or 6 bike lengths if we go from a dig its close for a while.