Ultimate throttle response and faster acceleration at your command UUC's exclusive-design "sprung hub" clutch design Stage II lightweight flywheel has been named one of European Car magazine's "Top 10 Products". Tipping the scales at only 8.5lbs, this aluminum flywheel boasts the best features in its class (high-speed balanced, correct dowel hole, replaceable friction surface. This Segmented Kevlar clutch option provides smooth engagement without any increase in clutch pedal effort and is intended for cars fitted with turbocharger or supercharger. The advantage of a sprung-hub clutch design is improved resistance (and in many cases, complete elimination) of the residual chattering noise at idle that some lightweight flywheel-equipped cars can experience. Because BMW specked this clutch for use on the powerful S38-series engine in the M5, it is up to the task of handling the output from a modified 3-series motor. UUC customers have been using the Stage 2 & M5 clutch setup in turbo or supercharged E46s with fantastic results. Our own testing has shown the M5 clutch to reliably handle in excess of 450hp. Kit comes complete with flywheel, clutch disk, clutch pressure plate, release bearing, alignment tool, gall plate, and crank bolts. No other parts necessary. Flywheel made in USA from T-6061 aircraft-grade aluminum with replaceable steel friction surface, and hardened starter ring. Flywheel is balanced to 11,000 rpm and spin-Burt tested to 14,000 rpm.