Spec Super Twin Clutch Kit – BMW 1M & N55 (E8x / E9x / F22 / F3x / F10)

OVERVIEW

SPEC's twin-disc kits for the E82 1M and the N55 cars that share its clutch and flywheel — 135i, 335i, 435i, 535i, M235i and Z4 sDrive35i.

The 1M's factory clutch is the same unit BMW fitted across the N55 range and it is the limiting factor on a tuned car well before anything else gives up. A twin-disc spreads clamp load across two discs, so it holds far more torque without needing the very heavy pedal a single-disc kit would require to reach the same number.

Super Twin kits are the full-size, highest-capacity option, supplied complete with a billet flywheel in steel or aluminum.

Trim level sets disc material and behavior: Organic is the most street-friendly; SS-Trim and P-Trim add capacity with firmer, more abrupt take-up; E-Trim is a rigid sintered race clutch.

SPECS

• SB53SST-O-1M — Super Twin Organic Trim, billet steel flywheel, rated to 720 lb-ft
• SB53SST-1M — Super Twin SS-Trim, billet steel flywheel, rated to 923 lb-ft
• SB53PT-1M — Super Twin P-Trim, billet steel flywheel, rated to 983 lb-ft
• SB53ET-1M — Super Twin E-Trim (rigid sintered), billet steel flywheel
• SB53SST-1MA — Super Twin SS-Trim, billet aluminum flywheel, rated to 923 lb-ft
• Torque figures are SPEC's published ratings for the complete assembly

PARTS INCLUDED

• Complete twin-disc clutch assembly with billet flywheel (steel or aluminum as selected by part number), friction discs, center floater plate, clutch cover, release bearing and hardware, as supplied by SPEC Clutch.

TECH RESOURCES

Additional Parts Required

• These kits are supplied complete with their flywheel — no separate flywheel purchase is needed.
• Clutch slave and master cylinder — worth replacing while the transmission is out.
• Transmission fluid — the transmission has to come out, so plan on a fluid change.
• Flywheel bolts — BMW flywheel bolts are single-use. Replace them.

Installation

• SPEC does not publish installation instructions or a fitting guide for its BMW twin-disc kits. Twin-disc assemblies need the floater plate correctly spaced and the discs correctly oriented — we strongly recommend professional installation. Contact Speed Logic for guidance or a shop recommendation.
• Break-in matters: SPEC specifies a gentle break-in period on new discs before the clutch is loaded hard.

Notes

• SPEC also indexes the SB53SST-O-1M under the part number SB53SST-1M-O. They are the same kit.
• Twin-disc clutches rattle at idle with the pedal up. This is normal and is not a fault.
• An aluminum billet flywheel reduces inertia further than steel but transmits more gear noise and makes smooth low-speed starts harder. Steel is the better street choice.
• Manual-transmission cars only.
• Price is for the clutch and flywheel assembly only; labor and fluids are not included.

PART NUMBER

• SB53SST-O-1M
• SB53SST-1M
• SB53PT-1M
• SB53ET-1M
• SB53SST-1MA

VEHICLE APPLICATIONS