ACT 2002 Subaru Impreza HD-M/Race Sprung 6 Pad Clutch Kit

The ACT SB9-HDG6 is a ceramic race clutch for the first US-market Subaru WRX, the 2002 to 2005 Impreza WRX with the EJ205 2.0L turbo and five-speed gearbox. Our listing is titled for the 2002 Impreza. It is aimed at the owner who has turned up the boost with a bigger turbo, a tune or a front-mount intercooler and now has a stock or worn organic clutch that slips at the top of second and third. If the car only commutes, the street kits linked below are a better fit; if it drag races, autocrosses or sees track days, this is the kit built for that heat.

What the SB9-HDG6 does in a 2002-2005 WRX

ACT rates the SB9-HDG6 at 555 ft-lb at the crank, 63 percent over the factory clutch. That number comes from two parts working together. The SB018 Heavy Duty pressure plate uses ACT's own diaphragm design for more clamp load with only a light to moderate pedal increase, and the 6228218 disc trades full organic facings for six ceramic pads on a 228 mm (9 in) disc with a 1 in, 24-spline hub. Ceramic tolerates far more heat than organic, which is why this kit out-holds ACT's Xtreme street kit even though its plate is lighter.

The disc is sprung. Springs in the hub damp the torsional pulses that a rigid race disc sends straight into the five-speed, which matters on a gearbox that is known to break when it is shock loaded by hard launches. Engagement is still on-off compared with organic, and ACT describes the feel as aggressive with OE to mild gear rattle.

The kit also carries ACT's Monoloc, a one-piece hardened chromoly retainer for the pull-type release bearing. It replaces the factory two-piece wedge collar and wire ring, so the bearing stays seated and loads the diaphragm evenly. In the box per ACT: SB018 pressure plate, 6228218 disc, RB601 release bearing, PB1004 pilot bearing and AT90 alignment tool. No flywheel is included.

Signs a WRX has outgrown its clutch

• Tach flares upward without a matching surge in speed when boost builds in 3rd or 4th
• A worn disc that slips after hard launches or a few autocross runs, then recovers once cool
• Hot, acrid smell after a drag pass or a hill climb
• Heat spots or blue discoloration on the flywheel at teardown
• Squeal or rumble from the bellhousing that changes as you press the pedal (release bearing)

A manual clutch has no sensor watching it, so a slipping WRX clutch usually sets no trouble code. Diagnosis is by feel and a load test.

How to confirm the clutch is the issue

Check the hydraulics first: fluid level, a firm pedal, no leaks at the slave cylinder, and correct free play. A clutch that does not fully release will grind into gear but will not slip. Next, roll in 4th at around 2,500 rpm and go to full throttle; if rpm rises faster than road speed, the clutch is slipping. Our slipping diagnosis guide walks through the test, and flare vs. slip helps rule out a boost or tune issue that feels similar.

Fitment

ACT's application list for SB9-HDG6 is the 2002-2005 Impreza WRX 2.0L turbo five-speed, 2004-2005 Forester XT and Baja Turbo with the EJ255, the 2005 Saab 9-2X Aero, 1991-1994 Legacy 2.2L turbo, 2007-2009 Legacy GT spec.B six-speed, and JDM WRX models. It does not fit the 2004-up WRX STI six-speed, the 2006-up WRX, or a non-turbo Impreza. Swapped cars should go by the gearbox actually installed. Compare the old clutch cover and release bearing with the new parts before install, or send us the year and VIN and we will check it. Other Subaru clutch parts are in our rebuild kits and clutches.

Choosing between ACT's SB9 kits

For a street-driven WRX with moderate power, the SB9-HDSS Heavy Duty street kit keeps the light pedal with an organic disc. If you want more clamp but still want a full-face organic disc, look at the SB9-XTSS Xtreme street kit. The HDG6 makes sense when heat, not clamp, is what keeps killing clutches.

Install notes

• Resurface the stock flywheel or fit the 600175 Streetlite (13.5 lb, street and race) or the 600170 Prolite (9.4 lb, race), the two flywheels ACT pairs with SB9 kits.
• Replace the pilot bearing with the supplied PB1004 and set up the Monoloc on the RB601 bearing per ACT's instructions before the gearbox goes back in.
• Center the disc on the AT90 tool and tighten the cover bolts in steps, in a star pattern, to factory torque.
• Bleed the clutch with the fluid printed on the reservoir cap.
• Race discs need only a few hard slips to lap in. Do not cook the clutch while doing it.

Will the SB9-HDG6 fit my 2004 WRX STI?

No. ACT lists SB9 kits for the 2002-2005 WRX 2.0L five-speed and the other turbo models in the Fitment section. The STI six-speed uses ACT's SB10 kits.

Can I drive a 6-pad ceramic clutch on the street?

You can, but ACT describes engagement as aggressive. Expect a grabby take-off in traffic. ACT recommends this kit for high-horsepower street or race use; for a daily driver, the organic SB9-HDSS or SB9-XTSS is smoother.

How much heavier is the pedal than stock?

ACT states its Heavy Duty plates typically raise pedal effort 15 to 40 percent, depending on the car, and describes this kit as light to moderate effort.

What else should I replace when installing it?

The kit includes the release bearing, pilot bearing and alignment tool. Resurface or replace the flywheel, inspect the rear main seal for leaks, and check the fork and pivot for wear while the gearbox is out.

Does it need a break-in?

ACT says race discs usually need only a few hard slips to lap the surfaces in before normal driving or racing, without overheating the clutch.

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