XClutch 04-22 Subaru WRX STi Type RA 2.5L Chromoly Flywheel
The XClutch XFSU003C is a single-mass 4140 chromoly flywheel for the Subaru WRX STI with the 2.5L EJ257 turbo and six-speed manual. It is the street version of XClutch's STI flywheel, so it is aimed at the owner who is doing a clutch and wants a fresh, strong friction surface without the idle rattle and touchy launches of a featherweight race part. Common reasons to buy: the old flywheel has blue hot spots or cracks after a slipping clutch, it has already been machined to the limit, or the new clutch maker wants a fresh surface.
Bolted to the back of the EJ257 crank, the flywheel is the surface the clutch disc is squeezed against, the carrier for the starter ring gear and a store of rotating mass that keeps idle steady and takeoff smooth. XClutch makes the XFSU003C from 4140 chromoly in one piece, with the ring gear integral and the timing sensor ring included where the application needs one. The XClutch catalog data marks it for street use and for single-disc clutches, and the maker's specification table lists a flywheel step of -0.583 inch, the recess between the friction face and the pressure plate mounting face.
That step matters. The pressure plate is designed around a specific step height, so pair this flywheel with a single-disc STI clutch built for the factory dimension. If you want the lighter, track-oriented version, the XFSU003CL lightweight flywheel is its sibling; our lightweight vs stock flywheel guide covers how much rev response you gain and what you give up in drivability.
Since a bad flywheel feels like a bad clutch, start with the clutch itself. Slip shows as rpm rising under boost in the higher gears while road speed stays flat; the road test in our slipping diagnosis guide applies. Our STI 6-speed problems guide helps separate gearbox noise from clutch noise. Once the transmission is out, check the face for cracks, measure runout and thickness, and use resurface vs replace to decide whether machining is still an option.
Our listing title reads 2004-2022 WRX STI. The compatibility table on the XClutch product page lists the 2006 through 2021 Impreza WRX STI and WRX STI with the 2.5L EJ257, every trim including Type RA, S209 and the special editions. It does not show the 2004-2005 STI or a 2022 model, and the US-market EJ257 STI ran from 2004 to 2021. Owners of a 2004 or 2005 car, a JDM 2.0L STI, a five-speed WRX or any engine or gearbox swap should send us the year and VIN before ordering so we can confirm. The standard hard parts collection lists other STI flywheels if this is not the one.
The XFSU003C is new, in stock and ships the same business day from the USA with a 1-year warranty.
| Brand | XCLUTCH |
| Part number | XFSU003C |
| Fits | XClutch 04-22 Subaru WRX STi Type RA 2.5L Chromoly Flywheel |
| Vehicle fitment | Subaru Wrx Sti Type Ra (2004-2022) |
| Type | Flywheels |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Our listing title includes 2004-2005, but the XClutch compatibility table we checked lists 2006-2021 WRX STI with the EJ257. Send us your year and VIN and we will confirm before it ships.
Both are 4140 chromoly single-mass flywheels for the STI. XClutch marks the XFSU003C for street use and the lighter XFSU003CL for track use. The standard XFSU003C is the better pick for a car that is driven daily.
No. XClutch lists this flywheel for single-disc applications. Twin-disc clutches are usually sold as an assembly with their own flywheel, so check what the kit you choose includes.
Yes. XClutch states its chromoly flywheels have an integral ring gear and a timing sensor ring where the application needs one.
Fit a new clutch kit matched to the STI flywheel step, a new pilot bearing, and inspect the release bearing, fork and pivot. XClutch also recommends checking the clutch hydraulics for wear during a clutch job.
