SPEC Stage 3+ Performance Clutch Kit (for SPEC single-mass flywheel) - E60 535i, E82 135i, E9X 335i

The SPEC Stage 3+ clutch has been engineered to stay in step with the above average upgrades done on the 135/335/535/Z4 35i. Everyone knows that adding large amounts of boost and torque will expose weaknesses in other areas - the clutch being near the top of the list. The factory clutch works just fine on a stock 335 or with a mild upgrade like software and intake. But when you get into serious torque levels the stock clutch simply can't handle it. SPEC has focused heavily on the 335 market with 5 stages of upgraded 335 clutches. Stage 2+ is our favorite for mildly-tuned 335s, offering near stock levels of refinement and ample torque capacity (rated for 545ft-lbs). But when going beyond the usual bolt-on upgrades you need to look at your weakest links. The Stage 3+ clutch is rated for 671 ft-lbs. This clutch kit is meant to be used only with a SPEC flywheel (not the stock flywheel).

The Stage 3+ is for cars making serious levels of boost and torque. If you have upgraded turbos or a single-turbo conversion, or have checked off the list of full bolt-ons, this will be a very capable clutch for you. This clutch is designed to work only with a SPEC single-mass flywheel and avoid the pitfalls of the stock OEM flywheel. The stock dual mass flywheel uses springs and rubber to isolate vibrations from the engine and transmission. However, on high mileage or abused flywheels the rubber can break down and the springs will become weak. A worn dual mass flywheel limits the amount of torque you can put out. It will affect clutch engagement, shifts, and power delivery. In some cases a total flywheel failure can rip apart the flywheel, clutch, and even transmission housing. With the SPEC single-mass flywheel the limitations of the stock flywheel are eliminated. The SPEC flywheel is a single mass design (no internal springs or rubber to fail) and is offered in a steel or aluminum material. The steel will better dampen vibration than the aluminum so it's the better choice for street use. The aluminum will have greater vibration and noise (gearbox rattle) that may not be acceptable for everyone. The clutch in this Stage 3+ kit is a sprung hub design so SPEC has done all they can to minimize the noise and vibration. It's also self-adjusting, like the factory design, and the engagement point can be adjusted. See comments below for characteristics of each.

The Stage 3+ can be configured a few different ways depending on how you intend to use the car -

#SB533F-2 Variant Use Comments "Sport"
SPEC steel flywheel daily driving;
occassional drag strip Use this with the SPEC steel single-mass flywheel.
The clutch will be stiffer than the factory design but it will grab harder and stay connected with far less chance of slippage. The engagement point is changed but most drivers adjust within the first 100 miles. The failure-prone dual-mass flywheel is eliminated and a steel single-mass is used instead. Expect more noise and vibration from the steel but better reliability and slightly better performance. "Super Sport"
SPEC aluminum flywheel more drag strip than street Use this with the SPEC aluminum single-mass flywheel.
The clutch will be stiffer than the factory design but it will grab harder and stay connected with far less chance of slippage. The engagement point is changed but most drivers adjust within the first 100 miles. The failure-prone dual-mass flywheel is eliminated and a lightweight aluminum single-mass is used instead. Expect a lot more noise and vibration with aluminum ("gearbox rattle") but better reliability and better performance. The engine will rev a lot faster too.
SPEC Clutch is one of the premier clutch and flywheel suppliers to the tuner market. They are often found on the most highly tuned import and domestic vehicles. They are recent players in the German car community with a special focus on the newer turbo BMW models with high torque output. SPEC has been proven time after time to provide superior performance, drivability, and longevity to the most hardcore enthusiasts around the globe.

E9X 335 SPEC Clutch Stage 2+ Kit contents:
+ carbon/semi-metallic clutch disc
+ heavy-duty pressure plate
+ heavy duty throw-out bearing
+ pilot bearing
+ clutch fork
+ alignment tool

Additional items we recommend:
pressure plate mounting bolts
flywheel mounting bolts (if removing flywheel)
ball pin
spring clip
rear main seal (if car has more than 70,000 miles)
input shaft seal
output shaft seal
exhaust gaskets

This item fits the following BMWs:
2008-2013 E82 BMW 135i 135is 1M
2007-2013 E90 BMW 335i 335xi 335i xDrive - Sedan
2007-2013 E92 BMW 335i 335is 335xi 335i xDrive - Coupe
2007-2013 E93 BMW 335i 335is - Convertible
2008-2010 E60 BMW 535i 535xi 535i xDrive
2009+ E89 Z4 Z4 35i Z4 35is (from February 2009 production date)