600521 is a Prolite flywheel, which is ACT’s lighter flywheel offering with lowest inertia. Prolite flywheels are designed for best throttle response and acceleration. Prolite flywheels are preferred for road racing or rally racing, and have reduced drivability. Materials are properly distributed for maximum strength, good heat tolerance and rigidity. ACT flywheels are serviceable and can be resurfaced with no need to purchase additional parts.

Feel
Noticeably improved engine response and acceleration, OE to mild gear rattle

Life
Heat-treated forging for strength and toughness, induction-hardened ring gears for maximum life

Quality
Assures correct external balance for manual shift engine using OE front counterweight

Recommended Use
Recommended for street and race use

ACT Difference
Forged, CNC machined and dynamically computer balanced for smooth high RPM reliability