Cusco has recently released their lightweight flywheel for the Subaru BRZ. A lightened flywheel modification is best known to be used when tuning a naturally aspirated engine.
By applying a lightened mass to the crankshaft axis, the energy required to start the rotational inertial is greatly decreased. Factory flywheels are designed to smooth out the revolutions of the engine and stabilize engine idle by applying weight to the mass, solely to cater to the general consumer market.
Cusco Chromoly Flywheels are 48% lighter and weigh 4.8kg (w/knockpins) as compared to the factory OEM 9.34kg. The initial rotational inertia for a factory flywheel is 1242.6 kgfm as opposed to the Cusco unit 58% less torque load of 526.8 kgfm. SCM435H Chromium Molybdenum steel is lightened and shaped using the Finite Element Method (FEM) for precise accuracy.