ACT HD/Performance Street Clutch Kit for 17-26 Civic Si

ACT HD/Performance Street Clutch Kit - 2017+ Civic Si 1.5T / 2023+ Integra

Your Civic Si's tuned and the stock clutch is slipping. You're on the throttle at 5,000 RPM in third gear and the RPMs climb but the car's not accelerating like it should. The clutch can't hold the torque anymore. You need something that grabs harder but you're not building a drag car and you don't want a clutch that chatters like a jackhammer in traffic or needs a 200-pound leg press every time you push the pedal. ACT's HC10-HDSS sits in the sweet spot. It holds 363 ft-lbs. That's 63% more than stock. It'll handle a Hondata tune making 250 whp, bolt-ons, autocross, or light track days without slipping. The pedal's not heavy. The engagement's smooth. You can drive it in stop-and-go without wanting to rip the thing out. This is a performance clutch you can actually live with on the street.

Here's What Happens When Stock Clutches Can't Keep Up

The stock 1.5T clutch was designed for a bone-stock car making 200 hp at the crank. It's fine for commuting. It's not fine when you've added a Hondata FlashPro and you're making 250 whp or when you're launching hard at autocross. The clutch starts slipping under load. You're accelerating hard, the RPMs jump up, but the car's not pulling as hard as it should because the clutch disc's slipping against the flywheel. You're losing power to clutch slip. ACT's Heavy Duty pressure plate clamps harder than the stock one. The diaphragm's heat-treated four times so it's not going to lose clamping force after 20,000 miles like a cheap clutch does. The disc uses organic friction material with high copper content. Copper moves heat away from the friction surface faster than cheap material so the disc doesn't fade when it gets hot. The disc's also got steel backing. That matters when you're dumping the clutch at 5,000 RPM on a launch. We've seen cheap clutch discs explode from the shock load. This one's not doing that.

Sprung Disc Means Your Transmission Doesn't Hate You

There's two ways to build a performance clutch disc. Sprung or unsprung. Sprung discs have springs in the hub that cushion the shock when you drop the clutch. Unsprung puck clutches are solid. No springs. Puck clutches grab like crazy and they engage like flipping a light switch. On or off. That's great for a race car. It's awful for a street car. Every time you let the clutch out with an unsprung puck, you're slamming the transmission input shaft. The gears take a hit. The synchros take a hit. Do that for 50,000 miles and your transmission's trashed. You also get insane gear rattle at idle because there's nothing damping the vibration between the engine and the trans. ACT's disc is sprung. The springs absorb the shock when you engage the clutch. Your transmission lasts longer. The engagement's progressive instead of sudden. You're not jerking your passenger's head off every time you shift. The trade-off is a sprung disc doesn't hold as much torque as an unsprung puck. But this clutch holds 363 ft-lbs. That's way more than stock and it's plenty for a street/track 1.5T making 250-300 whp. If you're making 400+ whp on a big turbo, you need a different clutch. For a bolt-on car with a tune, this is perfect.

Break It In Right or It's Junk in 1,000 Miles

New clutches have to bed in or they'll glaze and slip forever. We've seen people install a brand new ACT clutch, go out and do a bunch of hard launches the first day, and cook the friction material before it's broken in. Now the clutch is glazed. It slips under load even though it's got 500 miles on it. Don't do that. Here's the break-in. First 500 miles: drive it normal. No hard launches. Don't slip the clutch to hold the car on a hill. Don't ride the clutch in traffic. You're letting the friction surface on the disc and the pressure plate mate together and develop a consistent contact pattern. After 500 miles you can beat on it. If you skip this and start launching the car on day one, you're overheating the friction material before it's had a chance to bed in. The surface hardens and gets shiny. That's glazing. Now it can't grip anymore. The clutch slips. You just burned $800. Break it in properly and it'll last 50,000+ miles.

Complete Kit - Everything's in the Box

This isn't just a disc and a pressure plate. You're getting a complete clutch kit. Pressure plate, disc, flywheel, all the bolts, throwout bearing, pilot bushing, alignment tool, and grease. Everything you need to install it is in the box. You're not reusing your old flywheel with a worn friction surface. You're not reusing a throwout bearing that's got 100,000 miles on it and is about to grenade. Everything's new. Install it and you're done.

What You Get

• ACT HD/Performance Street Sprung clutch kit - part number HC10-HDSS
• Holds 363 ft-lbs torque (63% more than stock)
• Heavy Duty pressure plate (four-stage heat-treated diaphragm, higher clamp load than stock)
• Performance Street sprung disc (organic friction material with high copper content, steel-backed for burst strength)
• Complete kit: pressure plate, disc, flywheel, pressure plate bolts, flywheel bolts, throwout bearing, pilot bushing, alignment tool, grease
• Sprung hub (protects transmission, smooth engagement, no harsh shock loading)
• Light to moderate pedal effort (not race clutch heavy)
• Mild gear rattle (way less than unsprung puck clutches)

Fits These Cars

• 2017-2021 Honda Civic Si 1.5T
• 2022-2024 Honda Civic Si 1.5T
• 2023-2024 Acura Integra A-Spec 1.5T
• 2023-2024 Acura Integra Base 1.5T

Note: Holds 363 ft-lbs (63% over stock) - supports bolt-ons, Hondata tune making 250-300 whp, autocross, light track use. NOT for 400+ whp big turbo builds (need full race clutch for that). Sprung disc protects transmission from shock loads - unsprung puck clutches hold more torque but destroy synchros and cause excessive gear rattle. Light to moderate pedal effort (not heavy like race clutch). MUST break in properly - first 500 miles drive normal, no hard launches, no slipping clutch on hills, no riding clutch in traffic or you'll glaze the friction material and it'll slip forever. We've seen people skip