ACT 2006 Mazda MX-5 Miata HD/Race Sprung 6 Pad Clutch Kit
ACT ZM4-HDG6 is for the NC Mazda MX-5 Miata owner who has outgrown an organic clutch: a turbo or supercharger build, regular track days, or autocross launches that leave the stock disc smelling hot. It combines ACT's Heavy Duty pressure plate with a 6-pad, spring-centered ceramic race disc for the 2006-2015 Miata with the 2.0L MZR four-cylinder. If the car is stock or lightly modified and driven daily, the street version listed below is the better match.
The pressure plate (ACT MZ032) uses ACT's own diaphragm design to raise clamp load and cut deflection, so the disc is squeezed harder without the pedal turning into a leg press. ACT expects pedal effort to rise roughly 15 to 40 percent with a Heavy Duty plate, depending on the car. The 6224508-1 disc is 224 mm (8.8 in) with six ceramic pads on a sprung hub. Ceramic tolerates far more heat than organic facing, and the springs still soak up driveline shock so the gearbox and differential see less of a hit on hard engagement.
ACT rates the kit at 359 ft-lb measured at the crank, 71 percent more than the OE clutch. The trade-off is engagement: ACT calls it aggressive, with harsher take-up but faster shifts, and lists the feel as light to moderate pedal effort with OE to mild gear rattle. It is built for high horsepower street or race use, not stop-and-go commuting.
Start with the hydraulics. A low or dark reservoir, air in the line or a weeping slave cylinder causes drag and grinding that feel like a bad clutch but are not slip. Then run a loaded test in fourth gear from low rpm at full throttle and watch the tach against road speed; our slipping diagnosis guide explains how to read it, and shift flare vs slip helps separate the two complaints. With the transmission out, look for oil from the rear main seal before installing a new disc.
Our listing names the 2006 MX-5 Miata. ACT's application table for ZM4-HDG6 runs from 2006 through 2015 on the NC with the 2.0L engine, listed by trim: Grand Touring and Sport for 2006, then Touring, GT, Grand Touring, Club, GS, GX, Special Edition and 25th Anniversary in later years. ACT catalogs the other NC trims under the ZM5 part number, which uses a different disc and alignment tool, so the kit has to match your transmission. Check whether the car has the five-speed or six-speed, and if you are unsure or it has had a gearbox swap, send us the year and VIN before you order. The ZM5-HDSS is the street kit on the ZM5 side.
| Brand | ACT |
| Part number | ZM4-HDG6 |
| Fits | ACT 2006 Mazda MX-5 Miata HD/Race Sprung 6 Pad Clutch Kit |
| Vehicle fitment | Mazda Mx-5 Miata Hd/Race Sprung (2006) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
ACT lists 2006-2015 NC MX-5 Miata 2.0L cars, by trim. Other NC trims use the ZM5 part number, so confirm five-speed or six-speed or send us your VIN.
ACT rates ZM4-HDG6 at 359 ft-lb measured at the crank, 71 percent over the stock clutch.
It can be. ACT describes engagement as aggressive and recommends it for high horsepower street or race use. The ZM4-HDSS street kit is smoother.
No. You get the pressure plate, 6-pad disc, release bearing, pilot bearing and alignment tool. Resurface or replace the flywheel at the same time.
Yes. ACT says Heavy Duty pressure plates typically raise pedal effort about 15-40 percent depending on the car.
Use gentle, varied engagement for the first few hundred miles before launching or tracking the car so the friction surfaces seat evenly.
