Product Specifications
- Manufacturer: Action Clutch
- Part number: ACR-0651
- Series: Stage 1
- Designation: 1OS
- Vehicle: 2002–2005 Honda Civic Si
- Engine: 2.0L DOHC K20A3
- Disc type: Full-face sprung organic
- Disc diameter: 8.5 inches
- Input shaft: 1-1/32 inch
- Spline count: 24
- Pressure plate: Single-diaphragm heavy-duty
- Flywheel: Lightened
- Flywheel weight: Approximately 10.07 pounds
- Ring gear: 119 teeth
- Published torque capacity: 182 lb-ft at the crank
- Total listed product weight: Approximately 26 pounds
- Recommended use: Heavy-duty street and mild track driving
- Break-in requirement: 500 street miles
What’s Included?
The complete kit includes:
- Lightened flywheel
- Heavy-duty single-diaphragm pressure plate
- Full-face sprung organic clutch disc
- Conventional release or throwout bearing
- Pilot bearing or bushing, when applicable
- Clutch-alignment tool
Including the flywheel removes the uncertainty of resurfacing a worn original unit and gives the clutch a fresh mating surface.
Stage 1 Street Performance
Action Clutch positions the 1OS kit for stock vehicles and cars with basic bolt-on upgrades. The full-face organic disc is intended to provide progressive engagement instead of the sudden on-off behavior associated with aggressive puck-style racing clutches.
Suitable modifications may include:
- Intake systems
- Header and exhaust upgrades
- ECU calibration
- Mild naturally aspirated engine work
- Street-oriented K20 upgrades
- Occasional autocross or track use
A heavily boosted K20 producing more than the manufacturer’s torque rating needs a higher-capacity clutch. Horsepower attracts attention, but torque is what the clutch actually has to hold.
For broader upgrade planning, read the Pro Street Performance Clutch Review for Street and Track and the detailed K-Series transmission differences guide.
Reinforced Organic Clutch Disc
The supplied description identifies a steel-backed copper-Kevlar organic friction material. This construction is designed to improve holding capability while preserving smooth takeoff characteristics.
The sprung hub helps absorb driveline shock between the engine and transmission. That matters in a daily-driven Civic Si, where low-speed engagement, parking and traffic behavior are more important than pretending every stoplight is a qualifying session.
Heavy-Duty Pressure Plate
The single-diaphragm pressure plate increases clamping force over a conventional replacement clutch while retaining a street-oriented pedal feel.
Actual pedal effort can still differ from the original Honda clutch. Hydraulic condition, clutch-master-cylinder wear, slave-cylinder operation and pedal adjustment also affect how the system feels after installation.
Lightened Flywheel Benefits
The included flywheel weighs approximately 10.07 pounds. Reducing rotating mass can allow the K20A3 to gain and lose engine speed more quickly.
Potential advantages include:
- Faster throttle response
- Quicker rev matching
- More responsive shifting
- Fresh friction surface
- Reduced rotating mass
Possible tradeoffs include:
- Easier stalling during takeoff
- Less rotational inertia
- Greater sensitivity to clutch technique
- Faster RPM drop between shifts
- Potential for additional drivetrain noise
A lightened flywheel doesn’t add horsepower. It changes how quickly the engine responds to throttle input.
Fully Enclosed Spring Retainers
Action Clutch uses enclosed spring-retainer construction around the disc hub. This design helps contain the damper springs and reduce the possibility of loose components damaging the bellhousing or transmission.
That’s a useful feature on a performance clutch because driveline shock, missed shifts and repeated hard launches can place considerably more load on the hub assembly.
Required 500-Mile Break-In
Action Clutch requires approximately 500 street miles of controlled engagement before hard use.
During break-in:
- Keep engine speed below 4,500 RPM.
- Use no more than half throttle.
- Avoid boost when applicable.
- Don’t launch the vehicle.
- Avoid clutch-kick techniques.
- Don’t perform dyno pulls.
- Use normal stop-and-go engagement.
- Avoid excessive slipping and heat.
Break-in allows the disc and flywheel surfaces to mate evenly. Ignoring it can reduce holding capacity, cause glazing and jeopardize warranty coverage. Yes, installing a performance clutch and immediately launching the car is tempting. It’s also a fast way to convert money into clutch dust.
Installation Notes
Clutch installation requires transmission removal and should be handled by an experienced technician or properly equipped DIY builder.
Inspect or replace the following during installation:
- Clutch master cylinder
- Clutch slave cylinder
- Rear main seal
- Transmission input-shaft seal
- Release fork and pivot
- Flywheel and pressure-plate fasteners
- Engine and transmission mounts
- Axle seals
- Manual-transmission fluid
Use the correct factory tightening sequence and torque specifications. Degrease the flywheel and pressure-plate friction surfaces before assembly, and never touch them with contaminated gloves.
Owners planning a swapped application should review the complete K20 swap guide before assuming ACR-0651 compatibility.
Warranty
The supplied listing advertises a limited warranty of 12 months or 15,000 miles. Confirm current terms directly with Action Clutch before installation.
Warranty eligibility may depend on:
- Correct vehicle application
- Professional installation
- Proper break-in
- No contamination
- Correct flywheel and pressure-plate torque
- Proper hydraulic adjustment
- Staying within the rated torque capacity
Keep the receipt, installation invoice and mileage record.
Is the Action Clutch ACR-0651 Worth Buying?
The ACR-0651 is a strong street-oriented choice for a 2002–2005 Civic Si with a stock or mildly modified K20A3. Its sprung organic disc should preserve reasonable engagement, while the lightened flywheel makes the engine feel more responsive.
Use the manufacturer’s official 182 lb-ft crank-torque capacity when deciding whether it suits the build. If the engine already exceeds that rating—or soon will—choose a higher-capacity kit instead of hoping the clutch respects optimistic marketplace copy.
Frequently Asked Questions
What vehicles does ACR-0651 fit?
Action Clutch officially lists it for the 2002–2005 Honda Civic Si with the 2.0-liter K20A3.
Does it fit an Acura RSX or K24 vehicle?
Action Clutch sells separate kits and SKUs for RSX, TSX, Accord and K24 applications. Don’t use ACR-0651 in those vehicles without direct manufacturer confirmation.
What is its torque capacity?
Action Clutch currently publishes a capacity of 182 lb-ft. This is a crank-torque rating.
Does the kit include a flywheel?
Yes. It includes an approximately 10.07-pound lightened flywheel.
Is it suitable for daily driving?
Yes. The full-face sprung organic disc is designed for heavy-duty street use and mild track driving.
How long is the break-in period?
The required break-in is 500 street miles with restrained RPM, throttle and clutch use.
Is this a six-speed clutch?
The 2002–2005 Civic Si uses a five-speed manual transmission. Verify the transmission and 24-spline input-shaft configuration before ordering.
There are no reviews yet.