Spec Stage 4 Clutch Kit Non-SAC SB554-2 – BMW 1M & N55 (E8x / E9x / F22 / F3x / F10)

OVERVIEW

The SPEC Stage 4 clutch kit is a solid-hub version of the Stage 3. The hub is solid 8-rivet and the assembly is heat treated for strength and durability. It is available in 3, 4 or 6 puck configuration — the 3 puck is the lightest, the 6 puck gives the smoothest engagement and the 4 puck sits between. It is street drivable in 6 puck form but not street friendly, because of the rigid hub. SPEC recommends it for drag racing, road racing, pulling, rally and drift.

This is the non-SAC version, built to run on a SPEC single mass flywheel. It is not compatible with the OEM dual mass flywheel, so a SPEC SB55S-2 or SB55A-2 flywheel must be fitted with it — add it in the option above, or choose “None” if you already have one.

SPECS

• Stage 4 single disc clutch kit
• Torque capacity: 580 ft-lbs (SPEC published)
• Friction material: carbon-graphite puck disc — 3, 4 or 6 puck
• Hub: solid 8-rivet, heat treated (rigid — not street friendly)
• Pressure plate: SPEC high-clamp, non-ratcheting
• Flywheel requirement: single mass flywheel required — not compatible with the OEM dual mass flywheel
• Built to order — ships in 1–2 weeks on average

PARTS INCLUDED

• Pressure plate
• Clutch disc
• Pilot bearing
• Release (throwout) bearing
• Alignment tool
• With a flywheel option selected: SPEC SB55S-2 steel or SB55A-2 aluminum billet single mass flywheel with pressure-plate-to-flywheel bolts

TECH RESOURCES

Additional Parts Required

• SPEC single mass flywheel — REQUIRED. Select it in the option above, or buy separately: SPEC SB55S-2 steel or SPEC SB55A-2 aluminum. This kit will not run on the OEM dual mass flywheel.
• Pilot bearing, release bearing and alignment tool are included in the kit.
• Installer-supplied: transmission jack, new flywheel-to-crank bolts and BMW-specification transmission oil if the transmission is drained.
• When switching to a single mass flywheel some flywheel chatter or rattle is to be expected.

Installation

• SPEC does not publish a downloadable installation PDF for this application — follow the printed installation and break-in instructions supplied with the kit.
• Installation requires removal of the transmission and should be carried out by a qualified technician. Inspect the pilot bearing bore, clutch fork, release-bearing guide sleeve and slave cylinder while the transmission is out.
• Bed the clutch in with light, gradual engagements before applying full load.

Notes

• Specify 3, 4 or 6 puck at checkout notes or contact Speed Logic; SPEC builds this kit to order.
• Steel is the better flywheel choice for a car that still sees daily traffic; aluminum is lighter but transmits more noise and makes smooth low-speed starts harder.
• Manual-transmission cars only. Confirm fitment with Speed Logic before ordering.
• 2011+ Z4 sDrive35i (N54) uses SPEC's N55-family clutch kit and SB55S-2 / SB55A-2 flywheel.

PART NUMBER

• SB554-2
• SB55S-2
• SB55A-2

VEHICLE APPLICATIONS