8 lbs is fine, I have a ACT Streetlite 12 lb on mine though. I also had it on my other GSR. Too lite of a flywheel is known to make your engine stall sometimes. I have heard 12 is the way to go, but I've also heard every lb taken off the stock flywheel (18) is 2 horsepower to the wheels. (not sure if I believe that, but hey)