Most OEM flywheels are heavy cast iron and are designed for optimum drivability by storing some of the engine's power in the form of inertia. The XACT Prolite flywheel is as light as ACT gets! Considerably lighter than stock, it provides lightning fast engine response and quicker acceleration. Every ACT flywheel is forged from a Chromoly billet material, CNC Machined to exact tolerances and precision balanced. Heating the billet and impacting it with a large 5000-ton mechanical forge yields an ultra fine grain structure in the metal, making it the absolute strongest flywheel available! The XACT Prolite flywheel is the preferred choice for road racing or low inertia and full race applications.