Clutch Masters 2-Piece Billet Aluminum Flywheels are made from the highest quality 6061-T6 or better grade aluminum. This material is chosen for its properties that are much more suitable for the environment than the one-piece chromoly units, with regards to heat dissipation and serviceability. The replaceable friction surface used is incredibly tough high carbon steel. This allows mating with any type of clutch friction material without worry. The starter ring gears are made of high carbon heat-treated steel for long lasting durability. The unit is buttoned together with military grade fasteners to make the premier flywheel in the industry. *Features* * Reduced mass equals increased acceleration. * A lightweight flywheel works particularly well with turbo-charged engines because it reduces typical turbo lag. * Increased supercharger efficiency due to less parasitic drag on the crank. * Improved mid-range torque in a normally aspirated engine due to not having to overcome the heavy weight of a stock flywheel. * CM uses only 6061-T6 aircraft grade or better billet aluminum in the manufacturer of its flywheels. * CM uses High Carbon steel for the friction surface. (Replaceable) * CM uses an OEM steel ring gear secured by bolts. * CM offers a limited lifetime warranty. * CM Billet Aluminum Flywheels meet SFI Spec 1.1 or 1.2