ACT 07-09 BMW 135/335/535/435/Z4 N54 XT/Race Sprung 6 Pad Clutch Kit

The ACT BM14-XTG6 is the high-power option for six-speed manual BMWs with the twin-turbo N54 or single-turbo N55: the 135i, 335i and 335is, 535i, 435i and Z4 sDrive35i. These engines pick up torque fast with a tune, and the factory clutch is usually the first thing to give up. If your car slips under boost on an aggressive map, upgraded turbos or ethanol, and you care more about holding power than a soft pedal, this is the kit built for it.

What this clutch kit does on an N54 or N55

BM14-XTG6 combines ACT's Xtreme pressure plate with a sprung-hub 6-pad ceramic race disc. ACT rates it at 702 ft-lb at the crank, 129 percent over the original clutch. The spring center damps driveline vibration that a rigid puck disc would pass straight into the gearbox, and ACT recommends the six-pad layout on larger clutches because it absorbs more heat. The disc is 240 mm (9.4 in) on a 1.375 in input shaft.

Kit contents per ACT are the B015X Xtreme pressure plate, the 6240530 6-pad sprung race disc, the RB105 release bearing, the AT118 and AT105 alignment tools and M8-1.25 x 20 mm pressure plate bolts. The flywheel is not included and ACT states the kit must be used with an ACT flywheel; ACT offers the 601030 XACT flywheel as the companion part, so the factory flywheel does not go back in.

Symptoms this kit is meant to fix

• Rpm flaring at full boost in third through sixth, often the first sign after a tune or turbo upgrade
• A clutch that holds at cruise but slips when boost comes in hard in the midrange
• Burning smell after a pull, or a high, vague engagement point
• A worn or rattling factory flywheel you are replacing anyway
• Release bearing noise with the pedal pressed, since the bearing is replaced here

How to confirm before you buy

A turbo BMW can feel flat for reasons that have nothing to do with the clutch, including boost leaks, wastegate problems and misfires. Log boost and rpm against road speed: if rpm jumps while speed and boost stay steady, the clutch is slipping. Also rule out a weak hydraulic system or oil from the rear main seal at the bellhousing. Our flare versus slip guide explains how to read that difference.

Fitment

Our listing title calls out 2007 to 2009 N54 cars. ACT's application chart for BM14-XTG6 goes further: 135i 2008 to 2013 (N54, then N55 from 2011), 335i and xDrive E90/E92/E93 2007 to 2013, 335is 2011 to 2013, F30 335i 2012 to 2015, F32 435i 2014 to 2016, 535i E60/E61 2008 to 2010 and F10 2011 to 2016, and Z4 sDrive35i 2009 to 2016. ACT splits several of those at January 2009 versus February 2009 production, so the flywheel you pair with this kit has to match your build date. Send us your VIN and we will confirm before it ships. Shipping weight is about 16.5 lb. See more parts in our rebuild kits category.

If the car is driven on the street most days, compare the BM14-XTSS organic street kit, which uses the same Xtreme plate with a smoother disc.

Install notes

• This is an aggressive disc. ACT describes moderate to heavy pedal effort and aggressive engagement, and says Xtreme plates add 50 to 80 percent pedal effort.
• Install the ACT flywheel with new bolts at the factory torque, then clean both friction faces with brake cleaner.
• Center the disc with the supplied tools and tighten the B015X cover in a star pattern with the included M8 bolts.
• Inspect the slave cylinder and fork while the gearbox is out, since a tired slave makes a heavy plate feel worse.
• Bleed with fresh brake fluid, which BMW clutch hydraulics share with the brakes; a pneumatic bleeder helps.
• ACT race discs need only a few hard slips to lap in the surfaces. Do not overheat the clutch while it beds in.

Does BM14-XTG6 come with a flywheel?

No. ACT states it must be used with an ACT flywheel, which is sold separately. ACT lists the 601030 XACT flywheel as the companion part.

Does it fit N55 cars as well as the N54?

Yes, per ACT's chart: 2011 to 2013 135i and 335i, F30 335i, F32 435i and F10 535i with the N55 are listed. Our title only names the N54 years, so send us your VIN to confirm.

How much torque does it hold?

ACT rates BM14-XTG6 at 702 ft-lb at the crank, 129 percent over the original clutch.

Is a 6-pad sprung disc OK on the street?

It can be driven on the street, but engagement is aggressive and take-offs need practice. ACT recommends it for high horsepower street or race use. A lightly modified car is better served by the organic BM14-XTSS.

Will it fit an automatic or DCT car?

No. This kit is for six-speed manual cars only.

• Shift Flare vs. Slip: How to Tell Them Apart
• How to Diagnose Transmission Slipping
• Automatic vs. Manual Transmission Repair Cost