Im running the Spec stage 2+ and Ive never had a problem with it. Ive done many hard launches and pulls and running 10psi with my evo3 16g turbo and its still holding up. AND the engagement is VERY VERY Smooth. It feels a little stiffer than the stock oem clutch, it has no harsh engagement. its also a Kevlar and Carbon-Graphite material And its rated at 375ft/lbs so it should be enough for running up to 15psi on the 16g.