Its a lot less restrictive than the ukspec one dude, allows the engine to rev alot more freely and takes out the flat spots in the rev range (apparently, mine is goin on next week i hope). Theres dispute over any ACTUAL BHP gains, some think maybe between 2-5bhp at the most, some say none, but it seems to be debatable dude, defo a good upgrade tho from the sounds of things. Phil.