Description Reviews Lightweight Crank Pulley! We have been installing these for years with zero issues. As long as you use they correct torque on the bolt, you will many trouble free years. The rule of thumb is that each pound of weight taken off the engines rotating assembly is worth approximately 2.7HP. The concept is that the crank is a parasite; it does not put power to the drive train, but still requires the traditional harmonic damper to protect against crank failure from torsional movement. This is not necessary in the MINI or most modern engines because of the many advances in engine design and materials. Factors such as stroke, displacement, inline, V configurations, power output, produced by the engine to rotate. When you reduce this parasitic weight, you release power that was previously used only for spinning the supercharger and alternator. Is this crank pulley safe? The pulleys on the R53's 1.6 and most new smaller engines have an elastomer (rubber ring) incorporated into the pulley that looks similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. We talked to the designer of this engine here in Detroit and the only time that the factory damper comes into play is at 850 RPM's. If you can increase your RPM idle speed up to 900, you will never be a factor, but you don't have too. Available in two options 0% stock diameter 2% over-sized for more boost Note: Torque Spec is 88 ft lbs. & comes with a new crank bolt. Instruction Link