Action Clutch Stage 4 Clutch Kit with Lightweight Flywheel - 2004-2008 Acura TSX
Building a dedicated race TSX or doing serious drag racing? The Action Clutch Stage 4 kit is an unsprung single-disc race clutch with a lightweight flywheel built for the 2004-2008 TSX. It's got a heavy-duty pressure plate and an unsprung 6-puck ceramic disc. The unsprung disc grabs way harder and faster than a sprung disc, but it transfers all the shock directly into your transmission. The lightweight flywheel reduces rotational mass so your engine revs faster. This is a race-only clutch. Don't put this in a street car. It chatters like crazy, the engagement is violent, and it'll beat your transmission to death if you're driving it on the street. If you're building a trailer-queen race car or a dedicated drag car, this clutch will hold serious power. If you're street driving at all, get the Stage 3 with the sprung disc instead.
Here's What Unsprung Means (And Why It's Brutal)
The Stage 4 uses an unsprung (rigid) 6-puck ceramic disc. There are no springs in the disc hub. The friction material bolts directly to the center spline with no cushioning in between. When you dump the clutch or shift hard, all the shock from engagement goes straight into your transmission gears and synchros. That shock is what cracks gears and destroys synchros over time. An unsprung disc is way more aggressive than a sprung disc, it grabs instantly with no cushioning. That's great for drag launches where you want instant engagement. But on the street, every shift beats your transmission and the clutch chatters constantly. This is why unsprung clutches are only for dedicated race cars that get torn down and rebuilt regularly. If you're street driving, the unsprung disc will destroy your transmission way faster than a sprung disc would.
Lightweight Flywheel Included
The Stage 4 kit includes a lightweight flywheel. The flywheel weighs way less than your stock cast iron flywheel, so your engine revs faster when you hit the throttle and it drops RPM faster when you let off. That makes the engine feel way more responsive. The downside is the engine's harder to launch smoothly because there's less stored energy to help you get moving. You need more throttle and more clutch slip to get off the line without stalling. The lightweight flywheel also creates more noise and vibration at idle. That's normal for race cars. If you want stock drivability, don't buy this kit.
170% More Holding Power Than Stock
Action Clutch claims this clutch has 170% more holding power than your stock clutch. The unsprung disc grabs harder and faster because there's no spring cushioning to absorb energy. The ceramic friction material handles extreme heat from repeated hard launches or extended racing without fading. If you're making big power and you're launching hard repeatedly, the unsprung disc won't slip like a sprung disc might under the same abuse.
It Chatters Bad and It's Not Going Away
This clutch chatters way worse than the Stage 3. You'll hear and feel violent vibration through the whole drivetrain every time you engage the clutch. It gets slightly better after break-in, but it never goes away. That's just how unsprung ceramic clutches work. The pedal's also heavier than the Stage 3. If you're trying to daily drive a car with this clutch, you're going to hate your life. It's loud, it's harsh, and every parking lot maneuver is annoying. This is a race clutch for race cars.
Race Only - Seriously, Not for Street Use
This clutch is for race applications, drag racing, and road racing. It's not intended for street use. The unsprung disc will destroy your transmission if you're daily driving. The constant shock from every engagement cracks gears and wears synchros way faster than a sprung disc. This clutch is for dedicated race cars that get rebuilt frequently. If your car sees any street driving at all, get the Stage 3 with the sprung disc. Don't be the guy who puts a race clutch in a street car and then wonders why your transmission is grenaded after 10,000 miles.
What You Get
- Action Clutch Stage 4 clutch kit with lightweight flywheel
- Heavy-duty single diaphragm pressure plate with reinforced drive straps
- Unsprung (rigid) 6-puck MIBA ceramic friction disc
- Lightweight flywheel
- Release bearing (throwout bearing)
- Clutch alignment tool
- 170% more holding power than stock (Action Clutch claim, not dyno-verified)
- RACE USE ONLY - NOT FOR STREET
Fits Your Car
- 2004-2008 Acura TSX (CL7/CL9 chassis, 6-speed manual, RACE USE ONLY)
Compatible Engines
- K24A2 (2004-2008 TSX)
Note: This is a race-only clutch. Do not install this in a street car. The unsprung disc will destroy your transmission from the constant shock loads if you're daily driving. This clutch is for dedicated race cars, drag cars, or trailer queens that get rebuilt regularly. If you drive your car on the street at all, get the Stage 3 with the sprung disc instead. The clutch chatters violently, the engagement is abrupt, and the pedal's heavy. That's normal for an unsprung race clutch. Break the clutch in properly - 500 miles of normal driving with no hard launches. Even though this is a race clutch, you still need to bed the friction material properly or you'll glaze it. The lightweight flywheel will be louder and harsher than stock. You'll hear more gear rattle and feel more vibration at idle. That's normal. If you're running this clutch and you're doing a lot of drag launches, expect to replace your transmission or rebuild it more frequently than you would with a sprung clutch. The unsprung disc beats your transmission hard.