Clutch Masters 94-04 Mazda Miata /MX-5 1.8L FX350 Clutch Kit
Clutch Masters 10905-HDFF is the FX350 clutch kit for the 1.8L Mazda Miata and MX-5, covering the 1994-1997 NA 1.8 and the 1999-2004 NB cars in our listing. It is for the Miata that has picked up a turbo or supercharger kit, or a heavily built naturally aspirated 1.8, and now slips when the power comes in. A stock-style clutch is cheaper, but on a boosted BP engine it is often the part that fails first at an autocross or track day.
A Miata clutch is small and light, which is part of why the car feels so sharp, but there is not much margin once you add boost. The FX350 steps up clamp with the Power Plus I high-leverage heavy duty pressure plate and swaps the organic facing for Clutch Masters Fiber-Tough friction, bonded to steel-backed segments on a heavy duty sprung hub. Clutch Masters rates this at a 110 percent gain in holding capacity.
The marcel spring wafer between the friction segments keeps take-up progressive, so it still works in traffic, though Clutch Masters is clear that the FX350 bites a little harder than its FX300 and will produce some chatter. It is aimed at medium-boost turbo or supercharger cars, well-built engines with cams and head work, or up to about 100 hp of nitrous. If your Miata is stock or close to it, the FX250 is the easier daily driver.
Pick a high gear at low rpm, go to full throttle and watch the tach. If engine speed rises without matching road speed, the clutch is slipping. On a Miata, check the clutch master and slave cylinders and the fluid before condemning the disc, and look at the bellhousing for oil from the rear main or input shaft seal. Our slipping diagnosis guide covers the test drive, and shift flare vs slip explains how to read what the tach is telling you.
Our listing reads 1994-2004 Mazda Miata and MX-5 1.8L. Clutch Masters lists 10905-HDFF for the 1994-2005 Miata MX-5 1.8L. The 1990-1993 1.6L cars use a different flywheel and clutch and do not take this kit unless the car has a 1.8L conversion, and the 2006-up NC 2.0L uses its own kits. Engine swaps are common in these cars, so send us your year, VIN and engine if anything has been changed. A milder kit for the same cars is the Clutch Masters 10905-HD0F FX250.
| Brand | Clutch Masters |
| Part number | 10905-HDFF |
| Fits | Clutch Masters 94-04 Mazda Miata /MX-5 1.8L FX350 Clutch Kit |
| Vehicle fitment | Mazda Miata /Mx-5 (1994-2004) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. Clutch Masters lists this kit for 1.8L Miata and MX-5 engines. The 1.6L cars use a different flywheel and clutch, so this kit only fits a 1.6 car that has been converted to a 1.8L engine and flywheel.
Clutch Masters lists 10905-HDFF for 1994-2005 1.8L cars. Our listing is written for 1994-2004, so send us your VIN if you have a 2005 and we will confirm before it ships.
It works on the street thanks to the sprung hub and marcel wafer, but Clutch Masters notes it engages more aggressively than the FX300 and will produce some chatter. If the car is stock or only lightly modified, the FX250 is easier to live with.
A flywheel is not in the box. The stock one must be resurfaced flat, or you can fit a lightweight steel flywheel at the same time. Clutch Masters notes lighter flywheels make more gear noise.
The clutch hydraulics share brake fluid, so bleed the slave cylinder with the brake fluid type printed on the reservoir cap after the install. Old, dark fluid is worth flushing out completely.
Clutch Masters asks for at least 500 miles of normal stop-and-go driving before hard use, with no full-throttle shifts or compression braking during that time.
