If you're looking to take your Mazda Miata's performance up a notch, the Advanced Clutch HD/Race Sprung 4 Pad Kit ZM2-HDG4 is definitely worth considering. I've had my fair share of clutches, and let me tell you, this one stands out. It features ACT's Heavy Duty pressure plate, which is known for its robust diaphragm design that really cranks up the clamp load. This means less deflection and a longer clutch life, which is something every enthusiast appreciates. Plus, the four-stage heat-treating process they use? That’s the kind of attention to detail that translates to real-world performance.

The pressure plate itself is built to last, with precision cover stampings that add rigidity—no flimsy parts here. Now, about the 4-pad spring-centered race disc: it’s designed to dampen torsional vibrations, which makes for a quieter ride. I’ve pushed this kit through some tough conditions, and I can vouch for its reliability. Sure, engagement is a bit harsher, but that’s what you want for faster shifts, right? It’s particularly great for smaller disc sizes in smaller engines like the Miata.

Installation is straightforward, and if you need a hand, you can grab the installation instructions here. It doesn’t come with everything—like the clutch master cylinder or pressure plate bolts—but it does include grease and an alignment tool, which is a nice touch.

In terms of features, you’re looking at a light to moderate pedal effort with aggressive engagement. The friction life is solid, thanks to that unique diaphragm design. It's engineered for high horsepower street or race use, and trust me, it’s been 100% clamp load tested and dynamically balanced for smooth high RPM reliability. The ceramic disc material can handle high heat, so you won’t have to worry about fading under pressure.

Here are some specs if you’re into the nitty-gritty:

• Clutch Disc Diameter: 8.8 in (224 mm)
• Input Spline Quantity: 22
• Input Shaft Diameter: 0.9375 in
• Torque Capacity: 310 ft/lbs
• Weight: 12.4 lbs

This kit fits the Mazda Miata from 1990-1997 and 1999-2005, making it a great upgrade for anyone looking to boost their ride's performance. If you're serious about your Miata, this clutch kit is a solid choice that won't let you down.