ACT 07-09 BMW 135/335/535/435/Z4 N54 XT/Perf Street Sprung Clutch Kit
ACT BM14-XTSS is the daily-driver answer for a tuned six-speed manual BMW with the turbocharged 3.0-liter six: the 135i, 335i, 535i, 435i and Z4 sDrive35i. Owners usually land here after a tune or bolt-ons, when the factory clutch starts to slip in the upper gears and they want a clutch that holds the power without a race disc's on-off engagement in traffic.
The kit pairs ACT's Xtreme pressure plate with its Performance Street sprung organic disc. ACT rates it at 549 ft-lb measured at the crank, which it lists as 79 percent above the original clutch. The Xtreme diaphragm is what supplies that clamp load; the disc is a full-face organic design with a high copper content for heat transfer, a steel-backed lining for burst strength and a sprung center that soaks up driveline vibration. ACT describes the result as smooth engagement with OE to mild gear rattle, which is why it is the version most street-driven cars should look at first.
Per ACT, the box contains the B015X Xtreme pressure plate, the 3000812 Performance Street sprung disc, the AT105 and AT118 alignment tools, an ACT release bearing (listed as RB015) and M8-1.25 x 20 mm pressure plate bolts. The disc is 240 mm (9.4 in) on a 1.375 in input shaft, and the kit weighs about 19.5 lb.
One requirement buyers miss: ACT states this kit must be used with an ACT flywheel, which is not included. ACT lists the 601030 XACT flywheel alongside it, so budget for the flywheel when you price the job.
Slip and a boost problem can feel the same from the driver's seat. Data-log rpm, boost and vehicle speed on a pull in a high gear: a clutch that slips shows rpm rising while speed does not follow, with boost on target. Low boost, a leaking charge pipe or a misfire points elsewhere. Check for oil at the bottom of the bellhousing too, since a leaking rear main seal will contaminate any new disc. Our guide to telling flare from slip and the slipping diagnosis guide walk through the logic.
Our title names the 2007 to 2009 N54 cars, but ACT's chart for BM14-XTSS is wider: 135i 2008 to 2013, 335i and xDrive E90/E92/E93 2007 to 2013, 335is 2011 to 2013, F30 335i 2012 to 2015, F32 435i 2014 to 2016, E60/E61 535i 2008 to 2010, F10 535i 2011 to 2016 and Z4 sDrive35i 2009 to 2016. ACT splits several models between production through January 2009 and from February 2009, and the flywheel you pair with the kit has to match that date. Manual cars only. Send us your VIN and we will check it before shipping. Browse more in our rebuild kits category.
Running big turbos, ethanol or track days? The BM14-XTG6 6-pad race version uses the same plate with a ceramic disc rated higher.
| Brand | ACT |
| Part number | BM14-XTSS |
| Fits | ACT 07-09 BMW 135/335/535/435/Z4 N54 XT/Perf Street Sprung Clutch Kit |
| Vehicle fitment | BMW 135/335/535/435/Z4 N54 Xt/Perf (2007-2009) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. ACT says the kit must run on an ACT flywheel sold separately, and lists the 601030 XACT flywheel as the matching part.
ACT's chart includes the N55 135i, 335i, F30 335i, F32 435i and F10 535i. Our title only lists the N54 years, so send your VIN and we will confirm fitment and the matching flywheel.
ACT rates it at 549 ft-lb at the crank, 79 percent over the original clutch. For more than that, look at the BM14-XTG6 race disc version.
Heavier than stock. ACT lists moderate to heavy pedal effort for this kit and says its Xtreme pressure plates add 50 to 80 percent effort, depending on the car.
ACT recommends 300 to 500 miles of mild engagement, such as stop-and-go driving, before racing or spirited driving with an organic street disc.
