I fitted one and had it on a dyno and was running on the lean side it was making about the same hp and torque as my unseat K&N filter,luckly for me the Tuner couldnt get TuneECU to talk to my bike saving me £200 so i never had set up 100%, but i didnt feel it made much difference over just having the secondries opened to 100% so i then refitted all the inducton plumbing which wasnt anywhere near as bad a people make out.