Clutch Masters 04-09 STi FX400 8 Puck Clutch Kit
Clutch Masters 15017-HDCL is the FX400 8-puck clutch kit for the Subaru WRX STI with the 2.5L turbo and six-speed, listed here for 2004-2009 cars. It is built for STIs that have gone well past stock power: bigger turbos, E85 tunes, or drag and road course use where an organic or Kevlar disc slips as soon as full boost arrives. If your STI is close to stock, this is more clutch than you need; the FX400 is aimed at holding torque, not at making a stock car smoother.
Clutch Masters rates the FX400 at 170 percent more holding capacity than stock. It combines the Power Plus I Hi-Leverage heavy-duty pressure plate with a sprung ceramic disc. The FX400 comes in two layouts, and the HDCL suffix is the 8-puck version: a segmented ceramic full-face disc that Clutch Masters calls the less aggressive of the two. According to the maker, the marcel cushion between the linings keeps chatter to a minimum, and this is the version it designs for street-driven cars. The 6-puck HDC6 paddle disc has no marcel, engages harder and can chatter in first and reverse.
The sprung hub provides moderate damping for high-torque engines, so the car stays far more drivable than with a rigid race disc. Ceramic friction sheds heat quickly and resists fade during launches. Clutch Masters is direct about the trade-off: ceramic discs are about holding power and durability, not longer life, and they are never recommended for stock or near-stock cars.
Log a pull in fourth from low rpm and compare engine speed with vehicle speed; if rpm climbs with no matching increase in speed as boost peaks, the clutch is not holding. Check the hydraulics before buying anything, because a leaking slave cylinder or air in the line causes poor release, not slip. Our slipping diagnosis guide covers the test, and the rebuild vs. replace guide helps if the six-speed itself is making noise and you want to plan both jobs at once.
Our listing is titled for 2004-2009 STI. The Clutch Masters application list for 15017-HDCL is broader: the WRX STI 2.5L turbo six-speed from 2004 through 2021, plus the 2006-2009 Legacy GT spec.B 2.5L turbo six-speed. It is not listed for the five-speed WRX. If your car is outside 2004-2009, has had a transmission swap, or runs an aftermarket flywheel, send us the year and VIN and we will confirm before you order. Other STI clutches and flywheels are in our rebuild kits and clutch collection.
| Brand | Clutch Masters |
| Part number | 15017-HDCL |
| Fits | Clutch Masters 04-09 STi FX400 8 Puck Clutch Kit |
| Vehicle fitment | Subaru Sti (2004-2009) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Both are FX400 kits with the same pressure plate. HDCL uses an 8-puck segmented ceramic full-face disc with a marcel cushion, which Clutch Masters calls the less aggressive, street-oriented version. HDC6 uses a 6-puck paddle disc without marcel that engages harder and may chatter.
Clutch Masters lists the WRX STI 2.5L turbo six-speed for 2004-2021 and the 2006-2009 Legacy GT spec.B 2.5L turbo six-speed. Our listing names 2004-2009 STI; send your year and VIN if your car is outside that range.
Usually yes. Clutch Masters says ceramic discs are never recommended for stock or near-stock cars, because harsh engagement and clutch slipping in traffic can shorten their life. A stock or lightly modified STI is better served by an organic or Kevlar kit.
The Power Plus I Hi-Leverage pressure plate, the 8-puck sprung ceramic disc, a release bearing, a pilot bearing where applicable, an alignment tool, an instruction card and decals.
A flywheel is not included. At minimum have the factory flywheel resurfaced; many owners fit a lighter steel or chromoly flywheel at the same time.
