ACT

Direct answer: The best ACT clutch for your Subaru depends on your power level and how you drive. The Heavy Duty Street sprung kit is the right call for a daily-driven WRX or STI with bolt-ons; the Xtreme Duty street disc suits higher-torque builds that still see street miles; and the Streetlite flywheel pairs with either to sharpen rev response. This collection is dedicated to ACT (Advanced Clutch Technology) clutch kits, flywheels, and hardware.

The factory clutch becomes the weak point once power climbs. ACT's sprung-hub street discs keep engagement smooth enough for traffic, while the heavy-duty and Xtreme pressure plates add clamping force to hold higher torque. A lightweight flywheel like the Streetlite lets the engine rev more freely, though revs also fall faster between shifts.

What to look for: match the kit's torque capacity to your build, not just your current power — headroom matters. Check whether the kit includes a flywheel or reuses the stock one, and confirm year range and transmission in the fitment notes, since WRX and STI clutches differ across generations.

ACT is the brand throughout this collection, with coverage for the WRX, STI, Legacy GT, and Forester XT, plus hardware like pilot bearings and the Monoloc collar.

Related pages: Clutch · Performance Flywheels · ACT Heavy Duty Street Kit w/ Flywheel (06-25 WRX) · ACT Xtreme Duty Kit (04-21 STI) · ACT Streetlite Flywheel (04-21 STI) · Our Top 3 Aftermarket Parts for the Subaru WRX Series

Does a clutch upgrade require a tune?

No. A clutch swap is a mechanical change — the ECU does not need recalibration. Give yourself a few drives to relearn the engagement point.

Do I need a break-in period for a new clutch?

Yes — follow the break-in procedure in the box: easy city driving for the first several hundred miles, no hard launches. Skipping break-in is the fastest way to glaze a new disc.

Do I need a new flywheel with the clutch?

Check your flywheel's condition first. Some kits include a flywheel; if yours does not, a worn or heat-checked flywheel should be resurfaced or replaced so the new disc beds in on a true surface.

Will a heavier clutch wear out my transmission?

A properly matched clutch does not damage a healthy transmission. Mismatching causes harsh engagement and extra driveline shock. Choose the duty rating that fits your power and use case.