ACT 17-19 Honda Civic Si HD/Race Sprung 6 Pad Clutch Kit
If your 1.5L turbo Civic Si is slipping in third and fourth once the boost comes in, or a tune and intake have outgrown the factory clutch, the ACT HC10-HDG6 is the race-grade answer for the 2017-2019 Si. It pairs ACT's Heavy Duty pressure plate with a 6-pad sprung ceramic disc and an XACT Streetlite flywheel, and ACT rates the package at 464 ft-lb at the crank, 109 percent over the stock clutch.
The L15B7 makes its torque low in the rev range, and a tuned car makes a lot more of it. The pressure plate clamps the disc against the flywheel; when that clamp load is not enough, the disc slips and glazes. ACT's Heavy Duty plate (H032 in this kit) raises clamp load through its diaphragm design, and the 240 mm ceramic disc (6240510) uses six pads instead of a full face, so it bites hard and sheds heat well. The sprung center keeps some torsional damping, which is why this kit stays usable on the street where a rigid disc would not. ACT calls it a conversion kit: the included Streetlite flywheel (601190) replaces the factory flywheel and is required.
Do a load test: in fourth gear at about 2,500 rpm, go to full throttle and watch the tach against road speed. If RPM jumps ahead of the car, the clutch is slipping. Then rule out the hydraulics: a sticking slave cylinder or a pedal that is not fully returning can hold the clutch partly released and mimic a worn disc. Our slipping diagnosis guide walks through separating real slip from other drivability problems, and the flare vs slip article explains what true slip feels like.
Be honest about how the car is used. ACT describes this kit as aggressive engagement with light to moderate pedal effort and OE to mild gear rattle, built for high-horsepower street or race use. If the car is a daily driver with a mild tune, the full-face organic HC10-HDSS street kit (363 ft-lb) will be easier to live with. If you want the same holding power with no damper springs for track use, look at the HC10-HDR6 rigid race kit. A 6-pad disc engages quickly, so expect a learning curve pulling away in traffic.
This listing covers the 2017-2019 Honda Civic Si with the 1.5L turbo and 6-speed manual. ACT's own application chart for HC10-HDG6 is wider: 2017-2020 and 2022-2026 Civic Si, 2017-2021 and 2022-2024 Civic 1.5T manual trims, 2018-2020 Accord 1.5T, and 2023-2026 Integra 1.5T. The disc uses a 24-spline, 1.0325 in input. It does not fit the 2.0L Civic Type R, which uses the HC12 family. If you are unsure, send us your year and VIN before ordering and we will confirm.
A spare clutch alignment tool kit is useful if you work on more than one car.
| Brand | ACT |
| Part number | HC10-HDG6 |
| Fits | ACT 17-19 Honda Civic Si HD/Race Sprung 6 Pad Clutch Kit |
| Vehicle fitment | Honda Civic Si Hd/Race Sprung (2017-2019) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
ACT lists 2017-2020 Civic Si (L15B7) in the application chart for this part number, so yes, even though our listing title says 17-19. Send your VIN if you want us to double-check.
No. ACT calls HC10-HDG6 a conversion kit and includes the XACT Streetlite flywheel 601190, which must be used with this pressure plate. Flywheel and pressure plate bolts are in the kit too.
ACT rates the kit at 464 ft-lb measured at the crank, 109 percent over the factory clutch. That covers most tuned and bolt-on turbo Si builds.
It engages more aggressively than stock because the disc has six ceramic pads. The sprung hub keeps vibration and gear rattle close to OE, but in stop-and-go traffic the street HC10-HDSS organic kit is smoother.
ACT describes pedal effort as light to moderate for this kit. Its FAQ says Heavy Duty plates typically add 15 to 40 percent pedal effort over stock depending on the car.
The kit already includes the release bearing, pilot bushing and flywheel. Inspect the slave cylinder and clutch line, and replace the gearbox fluid while it is drained.
