Spec Clutch SB64A-4 Billet Aluminum Lightweight Performance Flywheel BMW M54

The Spec Clutch SB64A-4 is a billet aluminum lightweight performance flywheel engineered for BMW M54-powered vehicles, including the 3-Series, 5-Series, Z3, and Z4. Designed as a high-performance replacement for the OEM cast steel flywheel, this flywheel reduces rotating mass to deliver sharper throttle response, faster revving, and improved powertrain efficiency.

Key Features:

• Aircraft-quality billet aluminum construction — significantly lighter than OEM steel flywheels, reducing parasitic drivetrain loss
• CNC machined to an industry-leading .001" tolerance — far tighter than the industry standard of .010", ensuring a perfectly flat seating surface and precise balance
• Replaceable steel friction plate — friction-enhancing steel surface is specially formulated for optimum clutch bedding and holding power, and can be replaced to extend the life of the flywheel
• SFI certified — meets or exceeds SFI safety standards for high-RPM racing and performance applications
• Designed for specific driving environments — engineered and weighted to complement how the BMW M54 platform reacts to changes in rotating mass
• Compatible with SPEC clutch kit stages — designed to pair with SPEC's full lineup of performance clutch kits
• Race bolt kit and flange plate included

SPEC flywheels are not a one-size-fits-all solution. Each unit is developed for a specific application to deliver optimal balance, drivability, and extended clutch life. The SB64A-4 is an ideal upgrade for street performance, autocross, and track day use. Part number: SB64A-4. Also referenced as SB64A4.