ACT HD/Perf Street Sprung Clutch Kit
The ACT NS1-HDSS is the mildest step up in ACT's SR20DET range, and for many street-driven Silvias it is the right one. It suits an owner whose turbo SR20 has an intake, exhaust and a little more boost, whose stock-style clutch has started to slip or wear, and who does not want a heavy pedal or a grabby disc in traffic. ACT builds it for the JDM Silvia K (S13/S14), Silvia Spec-R (S15) and Bluebird SSS Attessa.
The kit pairs ACT's N015 Heavy Duty pressure plate with the 3000405 Performance Street sprung disc. The Heavy Duty plate uses a revised diaphragm to raise clamp load and reduce deflection; ACT puts the pedal effort increase for its Heavy Duty plates at roughly 15 to 40 percent over stock depending on the car, and describes this kit's feel as light to moderate with smooth engagement and OE to mild gear rattle. The disc is organic with a high copper content and a steel-backed lining, 240 mm (9.4 in) on a 1.0 in input shaft. ACT rates the combination at 370 ft-lb at the crank, 49 percent over the original clutch.
Within the NS1 family, the NS1-XTSS uses the same disc on the stiffer Xtreme plate for 445 ft-lb with a heavier pedal, and the NS1-HDG6 moves to a 6-pad ceramic disc for 475 ft-lb with far harsher take-up. Choose the HDSS if the car is driven daily and power is moderate.
Do a fourth-gear pull from low rpm into boost. If the tach rises faster than road speed, the clutch is slipping. Grinding into gear or a soft pedal points to the hydraulics or release side instead, so check fluid, slave cylinder and master cylinder before pulling the transmission. Our transmission slipping diagnosis guide covers the load test, and shift flare vs slip explains how slip differs from other complaints.
ACT lists the NS1-HDSS for JDM SR20DET applications only: 1990-1998 Nissan Bluebird SSS Attessa 2.0L turbo, 1991-1998 Silvia K (S13/S14) 2.0L turbo five-speed RWD, and 1999-2002 Silvia Spec-R (S15) 2.0L turbo six-speed RWD. US 240SX chassis swapped to an SR20DET with its own transmission commonly use it too. A 240SX still on the KA24 and factory gearbox needs a different kit. If you are not sure which engine, transmission and flywheel are in the car, send us those details and we will confirm. More SR20DET clutches and flywheels are in our rebuild kits collection.
| Brand | ACT |
| Part number | NS1-HDSS |
| Fits | ACT HD/Perf Street Sprung Clutch Kit |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
ACT lists it for the SR20DET Silvia and Bluebird. It suits a 240SX swapped to the SR20DET with an SR20 transmission. A KA24 240SX with its factory gearbox needs a different clutch.
ACT rates it at 370 ft-lb measured at the crank, 49 percent over the original clutch.
ACT describes it as light to moderate with smooth engagement. Heavy Duty plates typically add 15 to 40 percent pedal effort over stock depending on the car.
The N015 pressure plate, 3000405 sprung organic disc, RB810 release bearing, PB1012 pilot bushing and AT01 alignment tool.
Yes. ACT recommends 300 to 500 miles of mild driving on organic street discs before racing or hard launches.
