If you're in the market for a clutch kit that can really handle the heat, the Advanced Clutch HD/Race Rigid 4 Pad Kit Z64-HDR4 is worth a look. This isn't just any clutch; it’s built for those who push their vehicles to the limit. With ACT's Heavy Duty pressure plate at its core, you're getting a design that’s been fine-tuned to boost clamp load, minimize flex, and extend the life of your clutch. Seriously, they’ve put these diaphragms through a rigorous four-stage heat treatment process, which means they can take a beating while still performing like champs.

What I really appreciate about this kit is the attention to detail. The pressure plates are precision-stamped to ensure they’re rigid and consistent, which translates to reliable performance when you're out on the track or just tearing up the back roads. And let’s talk about the 4-pad rigid race discs—crafted from high-quality ceramic friction materials, they’re not just tough; they’re designed for quick shifts and smooth operation. Sure, the engagement might feel a bit harsher, but that’s the trade-off for faster shifting, and trust me, it’s worth it, especially if you’re running a smaller engine setup.

Now, if you're thinking about installation, you'll want to check out the install instructions here. It’s not the hardest job in the world, but having a guide makes things a whole lot easier.

Features:

• Light to moderate pedal effort, but expect aggressive engagement and a bit of gear rattle.
• Moderate friction life, extended thanks to ACT's smart diaphragm design—though keep in mind, the rigid setup might wear out your spline a bit faster.
• All components are engineered and balanced with precision, using select ceramic materials that can withstand high heat for maximum performance.
• Best suited for race applications only, so if that's your jam, you're in the right place.
• Each unit is 100% clamp load tested and dynamically balanced to ensure smooth operation at high RPMs.

Specifications:

• Clutch Master Cylinder: Not included
• Grease: Included
• Grade Type: Performance
• Pilot Bushing: Not included
• Pressure Plate Type: Heavy Duty
• Release Bearing: Included
• Clutch Disc Diameter: 9.4 inches (240 mm)
• Disc Material: Ceramic
• Input Spline Quantity: 23
• Input Shaft Diameter: 1 inch
• Alignment Tool: Included
• Disc Type: Solid
• Pressure Plate Bolts: Not included
• Clutch Slave Cylinder: Not included
• Flywheel Bolts: Not included
• Pilot Bearing: Included
• Product Weight: 14.4 lbs
• Torque Capacity: 420 ft/lbs
• Torque Capacity Over OE: 0.72

Fitment:

• Ford Probe (1989-1992)
• Mazda 626 (1988-1991)
• Mazda MX-6 (1988-1992)

All in all, if you're serious about performance and want a clutch that can stand up to the rigors of racing, the Z64-HDR4 is a solid choice. It’s built tough, shifts quick, and will definitely give you the edge you need on the track.