ACT Heavy-Duty Race Clutch Kits ZM12-HDR4

ACT offers heavy-duty race transmission clutch kits for a variety of BMW applications. The kits feature ACT's most popular heavy-duty pressure plates—which use exclusive diaphragm design to increase clamp load, reduce deflection, and maximize clutch life. All diaphragms endure a 4-stage, heat-treating process for unparalleled performance. ACT pressure plates have precision cover stampings to provide rigidity and consistency. The 6-pad, spring-centered race discs feature a spring-center to properly damp torsional vibrations and resist failure under harsh conditions. Spring retainers utilize wraparound spring windows and thicker retainer stampings for spring support, reduce stress concentrations, and increase strength and reliability. With the 6-pad, spring-centered race disc (recommended for larger clutch sizes to absorb more heat), engagement is harsher, but shifting is faster. Available in sprung or solid hub style.

* Feel: Light to moderate pedal effort, aggressive engagement, OE to mild gear rattle
* Life: Moderate friction life, extended by ACT's exclusive diaphragm design
* Quality: Carefully engineered, precisely assembled, accurately balanced; uses select ceramic friction materials for high heat tolerance and maximum performance
* Recommended Use: Recommended for high horsepower street or race use
* ACT Difference: 100 percent clamp load tested and dynamically computer balanced for smooth high RPM reliability

Kits include:

* Heavy-duty pressure plate
* Alignment tools
* 6-pad solid or sprung race disc
* Release bearing

Brand: Advanced Clutch Technology
Manufacturer's Part Number: ZM12-HDR4
Part Type: Clutch Kits
Product Line: ACT Heavy-Duty Race Clutch Kits
HP Direct Part Number: ACL-ZM12-HDR4
UPC: 842385018030
Clutch Usage: Performance
Clutch Disc Quantity: 1
Flywheel Included: No
Input Spline Quantity: 22
Input Shaft Diameter: 0.938 in.
Disc Diameter (in.): 8.800 in.
Disc Diameter (mm): 224mm
Disc Material: Ceramic
Disc Style: 4-paddle
Hub Style: Solid
Pressure Plate Style: Diaphragm
Throwout Bearing Included: Yes
Throwout Bearing Style: Standard
Alignment Tool Included: Yes
Pilot Bushing Included: Yes
Pilot Bushing Material: Steel
Counterweight Assist: No
Mounting Hardware Included: Yes
Quantity: Sold as a kit.
Notes: Must use ACT 600870 flywheel or a modified OE flywheel. 600870 flywheel is compatible with the OE clutch kit as wells as an ACT clutch kit. Torque capacity 399 ft. lbs.