I just picked up an m4 full system for my 3rd gen, install was a bit of a hassle since there is no room but got it taken care of. Originally had an m4 gp slip on with a gutted header. It made 178 on 93 octane and 186 on e85. After install it made 184 on 93 and 190 on e85. My tuner compared it to a friend's 2009 zx10 on mr12 with full Yoshimura and my bike made 4 more than his. ?? definitely a well spent 875 dollars.