If you're serious about performance, you might want to take a closer look at the Advanced Clutch HD/Race Sprung 4 Pad Kit ZM8-HDG4. This isn't just another clutch kit; it's a serious upgrade for your Mazda RX-8, especially if you've got the need for speed from 2004 to 2011 models. The backbone of this kit is ACT's Heavy Duty pressure plate, which is designed with an exclusive diaphragm setup that really cranks up the clamp load. What does that mean for you? Less deflection and a longer clutch life, so you can focus on driving instead of worrying about your setup.

Now, let’s talk about the performance. The pressure plates go through a rigorous four-stage heat-treating process, ensuring they can handle the heat when you push your RX-8 to its limits. Plus, the cover stampings are precision-engineered for extra rigidity and consistency, which is crucial when you're shifting gears at high RPMs. The 4-pad spring-centered race disc is where the magic happens—it's built to reduce torsional vibrations, making your ride quieter while still being tough enough to handle harsh conditions. Just keep in mind, the engagement is a bit harsher, but that means faster shifts, which is what you want on the track or the street.

Installation is straightforward, but you might want to check out the install instructions here to get it right the first time. And if you're concerned about pedal feel, this kit balances light to moderate effort with aggressive engagement and just a hint of gear rattle—nothing too crazy, but enough to remind you that you're driving something special.

On the tech side, you're looking at a clutch disc diameter of 9.4 inches (or 240 mm) and a torque capacity of 420 ft/lbs, which is a nice bump over the stock setup. It's designed for high horsepower street or race use, and it’s been 100% clamp load tested and dynamically balanced for reliability when you’re pushing it hard. Just a heads up: the flywheel needs a counterweight, and you’ll need to grab that separately if you don’t have one already.

In short, if you want a clutch that’s engineered for performance and built to last, this kit is worth considering. It’s not just about numbers; it’s about the feeling you get when you hit the gas and know your car is ready to unleash its full potential.

Features:

• Light to moderate pedal effort with aggressive engagement
• Moderate friction life, extended by ACT's diaphragm design
• High heat tolerance with select ceramic friction materials
• Perfect for high horsepower street or race applications
• 100% clamp load tested and dynamically balanced for smooth operation

Specifications:

• Clutch Master Cylinder Included: No
• Grease Included: Yes
• Grade Type: Performance
• Pilot Bushing Included: No
• Pressure Plate Type: Heavy Duty
• Release Bearing Included: Yes
• Clutch Disc Diameter: 9.4 in (240 mm)
• Disc Material: Ceramic
• Input Spline Quantity: 23
• Input Shaft Diameter: 1 in
• Alignment Tool Included: Yes
• Disc Type Sprung Solid: Sprung
• Pressure Plate Bolts Included: No
• Clutch Slave Cylinder Included: No
• Flywheel Bolts Included: No
• Pilot Bearing Included: Yes
• Product Weight: 15.4 lbs
• Torque Capacity: 420 ft/lbs
• Torque Capacity Over OE: 0.72

Notes:

• Flywheel requires a counterweight (sold separately or with flywheel kit). Be sure to use ACT counterweight with ACT flywheel.

This clutch kit is a solid choice if you're ready to take your RX-8 to the next level.