ACT 2006 Subaru Impreza HD/Perf Street Sprung Clutch Kit (5 SPD)
A 2006 Impreza WRX with the 2.5L turbo and 5-speed is the car this listing is filed under, and the usual reason owners shop for it is a clutch that slips once a tune or bolt-ons raise boost. The ACT SB11-HDSS is ACT's most street-friendly upgrade for that car: Heavy Duty pressure plate, organic sprung disc and a Streetlite flywheel that keeps the drive close to stock. ACT lists the same kit for many other turbo Subarus, covered under Fitment below.
ACT calls SB11-HDSS a conversion kit. It replaces the original 230 mm clutch with a 240 mm clutch, and because that larger disc needs a matching friction surface, ACT requires its own flywheel and includes the 600890 XACT Streetlite. Streetlite is ACT's heavier, smoother flywheel option, so idle and low-speed manners stay closer to factory than with the lighter Prolite used in the SB12 kits. The full kit weighs 28.6 lb.
ACT rates the kit at 449 ft-lb at the crank, 46 percent over the stock clutch. The SB020 Heavy Duty plate raises clamp load through ACT's diaphragm design, and the 3000505 Performance Street disc uses a copper-rich organic lining on a sprung hub that soaks up driveline shock. ACT describes the feel as light to moderate pedal effort with OE to mild gear rattle. For more capacity there is the SB11-XTSS Xtreme street kit, or the SB11-HDG6 6-pad race kit for launches and track use.
Run a fifth-gear pull from about 2,500 rpm. A sudden rise in rpm without matching acceleration means the disc is slipping. Rule out the cheap causes first: low or contaminated clutch fluid, air in the line, or a pedal that is not returning all the way can leave the clutch partly released. Oil dripping from the bellhousing seam points to a rear main seal that should be fixed during the job. See our flare vs. slip guide and slipping diagnosis guide, plus clutch chatter causes if shudder is the main complaint.
ACT's application list for SB11-HDSS: 2006-2011 Impreza WRX 2.5L turbo 5-speed, 2012-2014 Impreza WRX and WRX 5-speed, 2005-2012 Legacy GT 5- and 6-speed, 2005-2009 Outback XT, 2006-2008 Forester XT, 2006 Baja Turbo, 2015-2021 WRX 2.0L turbo 6-speed and 2022-2026 WRX 2.4L turbo 6-speed. It is not listed for the US STI. ACT notes that Subaru moved to 240 mm clutch parts in mid-2018 model year production starting at VIN J806877, and ACT kits and flywheels are not compatible with that revised hardware. On a 2018 or later WRX, send us your year and VIN before ordering. More Subaru clutch parts are in our rebuild kits and clutch section.
| Brand | ACT |
| Part number | SB11-HDSS |
| Fits | ACT 2006 Subaru Impreza HD/Perf Street Sprung Clutch Kit (5 SPD) |
| Vehicle fitment | Subaru Impreza Hd/Perf (2006) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Yes. ACT lists it for the 2006-2011 Impreza WRX 2.5L turbo 5-speed. It does not fit the non-turbo 2.5i or the US STI.
ACT lists 2015-2026 WRX, but warns that Subaru switched to 240 mm clutch parts from VIN J806877 in mid-2018 and ACT kits are not compatible with that revised hardware. Send us your VIN to check.
No. ACT requires its own flywheel with this conversion kit and includes the 600890 Streetlite flywheel.
ACT rates SB11-HDSS at 449 ft-lb at the crank, 46 percent more than the factory clutch.
They share the SB020 plate, 3000505 disc and 449 ft-lb rating. SB11 uses the heavier Streetlite flywheel for smoother low-speed driving; SB12 uses the lighter Prolite flywheel.
