Madness and ACT have developed the ultimate flywheel for the R53 MINI. Made from one solid piece of CroMoly steel this flywheel weighs in at 13.8lbs (6.25kg) Spun Balanced to 8000rpm and one piece design mean trouble free performance for years to come. Key Features - XACT Flywheel 01 ACT flywheels are lighter, stronger and safer than stock cast flywheels to meet the needs of both enthusiast and hard core racer. 02 Material is properly distributed for maximum strength, lower inertia, good heat tolerance and rigidity. 03 One piece construction allows less opportunity for failure and provides uniform efficient heat transfer from the clutch disc. No more warped inserts or loose ring gears. 04 Integral ring gear permits more weight reduction where it matters most and eliminates the chance of gear breakage or separation from the flywheel. 05 Precision machined threads will not easily strip out or get damaged like those found on aluminum flywheels. 06 ACT engineers XACT flywheels using the latest CAD and FEA (finite element analysis) software to evaluate all design alternatives to get the best results possible. 07 By hot forging chrome-moly steel, each flywheel yields an ultra fine centralized grain structure that is superior in strength to any other manufacturing method. 08 Timing marks are precisly located and clearly displayed (when applicable). 09 ACT gives extra effort to strategically slot XACT ProLite flywheels to lower inertia without sacrificing strength and heat dissipation. 10 ACT heat treats the entire forging for strength and toughness, and induction hardens their ring gears for longest gear life. 11 XACT Flywheels are certified as meeting SFI Specification 1.1. XACT Flywheels are legal for competition in all racing organizations where SFI certification is required. 12 Ring gears are cut with lead-in chamfers for better starter engagement and prevention against rounding off gear teeth. 13 Engineers at ACT demand tight tolerances for fit, concentricity and parallelism so that flywheels will have an exact fit onto the crankshaft, and operate smoothly even at extremely high rpm. 14 All flywheels are CNC machined and dynamically computer balanced for super smooth high RPM reliability. This is a special order item