Spec Stage 2+ Clutch Kit – BMW 335i / 435i / M235i (F30 F32 F22)

OVERVIEW

The SPEC Stage 2 PLUS clutch kit uses a multi-friction disc in a full-faced configuration, carbon semi-metallic on one side and Kevlar on the other. Bridging the gap between Stage 2 and Stage 3, the 2+ keeps the drivability and engagement quality of the Stage 2 but carries 15–20% more torque capacity. The hub is double sprung with spring cover relieves for flexibility and the components are heat treated for strength and durability. SPEC recommends it for street, drag, autocross, road racing, pulling, rally and drift use.

This is the ratcheting (SAC) version for the N55 cars, so it runs on the OE dual mass flywheel or on a SPEC SB55S / SB55A billet single mass flywheel. SPEC builds more than 700 vehicle-specific models in the Stage 2 Plus line.

SPECS

• Stage 2+ single disc clutch kit
• Friction material: multi-friction full-faced disc — carbon semi-metallic on one side, Kevlar on the other
• Torque capacity is 15–20% above the SPEC Stage 2
• Hub: high-torque double sprung hub with spring cover reliefs, heat treated
• Pressure plate: SPEC high-clamp, self-ratcheting (SAC) design
• Kit weight: 16 lbs (SPEC published)
• Character: SPEC lists street, drag racing, pulling and autocross, and also rates it for road racing, rally and drifting
• Flywheel requirement: runs on the OE dual mass flywheel or a SPEC SB55S / SB55A billet single mass flywheel — a SPEC flywheel is optional

PARTS INCLUDED

• Pressure plate
• Clutch disc
• Pilot bearing
• Release (throwout) bearing
• Alignment tool
• Bearing and tool kit included
• SPEC clutch kits supplied for use with the OEM dual-mass flywheel include pressure plate, disc, pilot bearing, release bearing, alignment tool and clutch fork.

TECH RESOURCES

Additional Parts Required

• None. SPEC specifies no additional hardware for this kit — it runs on the OE dual mass flywheel and includes its own bearing and tool kit.
• Optional single mass flywheel upgrade (SAC pattern): SPEC steel SMFW SB55S. SPEC also lists an SB55A aluminum version for this application.
• If the OE dual mass flywheel is being reused it must be inspected and, where serviceable, resurfaced before the new clutch is fitted.
• Installer-supplied: transmission jack, new flywheel-to-crank bolts and BMW-specification transmission oil if the transmission is drained.

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

• SPEC lists SB553H across a wider range of N55 and B58 BMWs than the chassis shown here. Confirm fitment with Speed Logic before ordering.

PART NUMBER

• Clutch kit: SB553H
• SPEC flywheel (SAC pattern), optional: SB55S steel or SB55A aluminum

VEHICLE APPLICATIONS