Clutch Masters 21-23 BMW M3/M4 3.0L S58 Factory Fit FX400 8-Puck Twin Disc Clutch w/Alum....

A tuned S58 makes far more torque than the factory clutch in a 2021 to 2023 BMW M3 or M4 six-speed was built to hold, and slip at full boost is usually the first sign. The Clutch Masters Factory Fit FX400 8-puck, part number 03240-HDCL-DLX, is the ceramic step of the Factory Fit line for owners who want real holding power for a hard tune but still drive the car on the street. The 8-puck version is the smoother of the two FX400 discs, built to bite hard without the chatter a race puck disc brings.

How the FX400 8-puck works in the G80 and G82

BMW put a twin disc clutch behind the S58 in manual cars: two friction discs with a floater plate between them, so the clamp load works across four friction faces. The Clutch Masters Factory Fit kit keeps that basic layout but drops the factory self-adjusting cover for a stamped steel cover, moves from 8.5 inch discs to 9.5 inch discs, and pairs everything with a Type 3 hard anodized aluminum flywheel and a steel floater. Clutch Masters puts the total weight savings at a little over 10 lb versus the factory assembly.

What sets the 8-puck apart is the friction. Clutch Masters describes its FX400 8-puck disc as a segmented ceramic full-face design with a sprung hub and a marcel cushion between the linings. Ceramic handles heat and torque far better than organic material, and the marcel cushion lets the facings compress slightly as the clutch engages. The result is the fast, positive engagement ceramic is known for, with minimal chatter. Clutch Masters says the 8-puck is the less aggressive FX400 option and is meant for street-driven cars.

Signs you have outgrown your current clutch

• The tach rises at full boost in the higher gears while road speed lags behind
• Slip began after a stage tune, a downpipe or a turbo upgrade
• A strong burnt smell after a launch or a track session
• The engagement point has crept up toward the top of the pedal
• A previous organic clutch wore out fast under hard use

How to confirm before you buy

Confirm the slip under load: in a high gear at low rpm, apply full throttle and see if rpm runs ahead of speed. Data logging makes it clear, since engine speed will climb without a matching rise in wheel speed. Before buying any clutch, check for a weeping slave or line, a soft pedal or a pedal that sticks low, any of which can hold the clutch partly open. Also check for oil on the bellhousing; an engine or input seal leak will glaze ceramic just as fast as organic. To plan the cost of the job, see our manual versus automatic repair cost guide.

8-puck, 6-puck or a softer stage?

Choose the 8-puck when the car is tuned well past stock and still sees regular street miles. If launches and track time come first and some chatter in first and reverse is acceptable, the FX400 6-puck is the more aggressive option. A mostly stock daily driver is better served by the organic-faced Factory Fit FX250.

Fitment

Listed for the 2021, 2022 and 2023 BMW M3 and M4 with the S58 engine and the six-speed manual gearbox. Automatic cars cannot use it. In North America the manual came only on the standard M3 and M4, so Competition and xDrive cars are not candidates unless they have been converted. If you have any doubt, send us your year and the last 7 of the VIN and we will check it before it ships. Browse the rest of our clutch and flywheel parts in the rebuild kits department.

Install notes

• The transmission has to come out. With it out, replace any leaking rear main or input shaft seal so the new ceramic faces stay dry.
• Mount the supplied aluminum flywheel with new bolts torqued to BMW's specification; do not reuse the factory flywheel with this disc set.
• Follow the stacking order in the instructions for disc, floater, disc and cover, center the discs with an alignment tool, and tighten the cover bolts a little at a time in a crisscross pattern.
• Bleed the clutch circuit with BMW-specified brake fluid until the pedal is firm; a pneumatic bleeder speeds this up.
• Break-in matters with ceramic: Clutch Masters requires at least 500 miles of normal driving, no full-throttle shifts and no compression braking.

What is the difference between the FX400 8-puck and 6-puck?

Clutch Masters says the 8-puck uses a segmented ceramic full-face disc with a marcel cushion, so it engages quickly with minimal chatter and suits street cars. The 6-puck has no marcel, engages harder and may chatter in first and reverse.

Will a ceramic clutch be hard to drive in traffic?

Ceramic engages faster than organic, so expect a shorter, more positive bite. The 8-puck's marcel cushion and sprung hub soften that, which is why Clutch Masters rates it for street-driven vehicles.

Does this fit the M3 Competition or M4 Competition?

Only a car with the six-speed manual. Competition and xDrive models in North America were automatic only, so this is for the standard manual M3 and M4.

Is a flywheel included?

Yes. The Factory Fit kit includes a Type 3 hard anodized aluminum flywheel, a steel floater, a stamped steel cover and two discs.

Do I need to break it in?

Yes. Clutch Masters requires a minimum of 500 miles of normal stop-and-go driving with no full-throttle shifting or compression braking before hard use.

• Automatic vs Manual Transmission Repair Cost