ACT offers a nice variety of clutch kits for the 2004-2009 Subaru STi. The street clutch is a good setup for stock or bolt-on modified vehicles, offering a heavy duty pressure plate with a street disc, for smooth engagement and long life. The 4-puck kit is designed for all-out race use, featuring a 4-puck race disc and heavy duty race disc for rapid, harsh engagement in drag-race applications. The 6-puck kit is a good midpoint between the street clutch and 4-puck system; it has more surface area that the 4-puck for smoother engagement, while the 6-puck disc makes it engage positively -- making it a good street/strip clutch. All ACT clutch kits for the 04-09 STi include a friction surface, a pressure plate, a throw-out bearing, and a alignment tool.

FITMENT: All 2004-2009 STI 2.5L - 6-Speed

	HD: Heavy Duty Pressure Plate
	The ACT Heavy Duty Pressure Plate is an excellent combination of increased torque holding and pedal feel for most daily driven cars. The HD pressure plate provides 40% increase in clamp loading while creating only a moderate increase in pedal feel thanks to ACT's special, single diaphragm design.
	SS: Performance Street Disc
	ACT's Performance Street friction surface is SFI certified and is an excellent choice for modified, street driven cars and race cars. The SS disc provides quicker engagement than a stock surface and is quiet compared to other, more aggressive, friction surfaces. The sprung hub uses bushings and cone springs similar to OEM clutch discs; this creates frictional dampening that improves clutch life and reduces noise
	XT: Xtreme Pressure Plate
	ACT's Xtreme Pressure Plate provides moderate to stiff pedal feel and provides a 54% increase in clamp loading. The XT pressure plate is SFI certified on virtually every application to ensure your safety in your modified street car or race car
	G6: 6-Puck Sprung Race Disc
	The ACT 6-Puck Sprung Hub Race Disc is SFI certified, so it is legal for all forms of racing that require SFI compliance. An ACT G6 race disc has a very durable friction surface with good spline life. The G6 was designed for a highly modified car that is drive to, on and from the track, as long as harsher engagement is acceptable. The sprung hub helps to reduce driveline shock and be relatively quiet compared to an unsprung hub, though the G6 can still be noisier than a full face disc and will have some chatter.
	G4: 4-Puck Sprung Race Disc
	An ACT 4-Puck Sprung Hub Race Disc has very harsh engagement and is designed for road race cars only. A G4 friction surface has good durability and spline life characteristics under normal use. The sprung hub helps to reduce driveline shock and be relatively quiet compared to an unsprung hub but will definitely have chatter. The ACT G4 is SFI certified, so it is legal for all forms of racing that require SFI compliance. We do not recommend the G4 for a daily driven/street car.
	R6: 6-Puck Solid Race Disc
	The reduced inertia of the ACT 6-Puck Solid hub allows for very fast shifts at the expense driveability. An ACT R6 race disc friction surface has very good durability but will have shortened spline life. ACT designed the R6 for a highly modified track cars where harsher engagement is expected and some clutch chatter is not a problem. The 6-puck layout of the R6 will absorb, and dissipate, more heat than a 4-puck unit. The ACT 6-Puck Solid Hub Race Disc is legal for all forms of racing that require SFI compliance. We do not recommend the R6 for any road going car.