ACT 2004 Subaru Impreza XACT Flywheel Streetlite
The ACT 600235 XACT Streetlite is a 15.6 lb one-piece chromoly flywheel for the Subaru WRX STI with the 2.5L EJ257 turbo engine and six-speed gearbox. Our listing names the 2004 Impreza, and that first US STI year is where the fitment starts, but the same part carries through the 2021 WRX STI and also covers the 2007 to 2009 Legacy GT spec.B. Most owners shop for it during a clutch job, when the factory flywheel shows heat cracks or hard spots, or when they want a quicker-revving engine without turning a daily driver into a rattle box.
On the EJ257 the flywheel is the rear friction face for the clutch disc, the carrier for the 124-tooth starter ring gear, and the rotating mass that steadies idle and low-speed engagement. ACT forges the 600235 from heat-treated chromoly, CNC machines it, dynamically balances it and induction-hardens the ring gear. The friction face is 240 mm (9.4 in) and the part carries SFI 1.1 certification. ACT calls Streetlite its most durable flywheel and rates the feel as noticeably better throttle response with OE to mild gear rattle. That is the honest difference from the 11.8 lb ACT Prolite: the Streetlite gives up a few pounds of weight savings to stay civil on the street, in traffic and on the daily commute.
Flywheel faults feel like clutch faults, so start with the basics. A slipping clutch shows as rpm climbing in fourth or fifth gear without road speed following; our slipping diagnosis guide walks through that road test and how to rule out other causes. With the gearbox out, check the old flywheel for cracks, measure runout with a dial indicator and look over every ring gear tooth. Light glazing can often be machined away, but cracks or deep hard spots mean replacement. ACT notes its own flywheels are serviceable and can be resurfaced later without buying extra parts, which matters on a car that will see several clutches in its life.
ACT lists the 600235 for the 2004 to 2014 Impreza WRX STI 2.5L turbo six-speed, the 2015 to 2021 WRX STI 2.5L turbo six-speed and the 2007 to 2009 Legacy GT spec.B 2.5L turbo with the TY856 six-speed. ACT also lists JDM and European 2002 to 2005 Impreza WRX STI Version 8 and 9 2.0L cars. It does not fit the five-speed WRX, the FA20 WRX from 2015 on, or automatic cars. If the car has a swapped engine or gearbox, send us the year and VIN before ordering. Other STI parts sit in our hard parts collection.
If the car is a dedicated track build that can live with more rattle, compare the lighter ACT 600240 Prolite. This Streetlite is new, in stock, ships the same business day from the USA and carries a 1-year warranty.
| Brand | ACT |
| Part number | 600235 |
| Fits | ACT 2004 Subaru Impreza XACT Flywheel Streetlite |
| Vehicle fitment | Subaru Impreza Xact (2004) |
| Type | Flywheels |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. ACT lists it only for six-speed EJ257 WRX STI cars from 2004 to 2021 and the 2007-2009 Legacy GT spec.B. The five-speed WRX and the 2015-up FA20 WRX use different flywheels.
ACT lists the Streetlite at 15.6 lb and the 600240 Prolite at 11.8 lb. The Streetlite is the street-friendly option with OE to mild gear rattle; the Prolite revs faster but rattles more.
Usually yes, as long as it is a 240 mm single-disc STI clutch that matches the stock step height. Check the clutch maker's flywheel requirements before you order.
Yes. ACT states its flywheels are serviceable and can be resurfaced with no need to buy additional parts. Have a machine shop keep the step height correct.
The flywheel itself needs no fluid or relearn. Bleed the clutch hydraulics after the job and top up the gearbox oil if any was lost during removal.
