ACT HD/Race Sprung 6 Pad Clutch Kit
ACT NS1-HDG6 is a six-pad ceramic clutch on a Heavy Duty pressure plate for the turbocharged Nissan SR20DET, as used in the Japanese-market Silvia K (S13 and S14), the Silvia Spec-R (S15) and the Bluebird. It is aimed at SR20 owners who have outgrown an organic clutch with more boost and a bigger turbo but still want a pedal that is easy to live with: the Heavy Duty plate keeps effort light to moderate where the Xtreme version gets heavier.
The disc carries six separate ceramic pads on a spring-centered hub. Ceramic tolerates the heat of repeated launches and clutch kicks far better than organic material, and the gaps between pads let that heat escape. The hub springs soften the torsional hit from the engine, which protects the transmission and keeps some street manners compared with a rigid race disc. ACT notes that with this disc engagement is harsher but shifting is faster.
Clamp load comes from ACT's N015 Heavy Duty pressure plate, which uses ACT's own diaphragm design to raise clamp force and reduce deflection without the stiff pedal of a race plate. ACT rates the complete kit at 475 ft-lb, 90 percent over the original clutch, on a 240 mm (9.4 in) disc with a 1 in input spline, and lists it as light to moderate pedal effort, aggressive engagement and OE to mild gear rattle, recommended for high horsepower street or race use. Compared with its siblings: the NS1-HDSS uses the same plate with a smooth organic street disc, and the NS1-XTG6 keeps this disc but moves to the Xtreme plate for more capacity and a heavier pedal.
Rule out the cheap causes first. A hydraulic line that needs bleeding, a master or slave cylinder that is leaking, or a pedal that does not return fully can all feel like a clutch problem. Check the bellhousing for engine oil, because a weeping rear main seal will soak any disc. Then do a full-throttle pull in fourth from low rpm and watch whether the tach runs ahead of road speed. Our slipping diagnosis guide covers the load test step by step, and shift flare vs. slip explains how to read a momentary flare against true slip.
Our listing does not name a vehicle, so here is the application ACT publishes for NS1-HDG6: the 1990-1998 Nissan Bluebird 2.0L turbo, the 1991-1998 Silvia K (S13/S14) with the five-speed, and the 1999-2002 Silvia Spec-R (S15) with the six-speed, all SR20DET. These are Japanese-market cars and ACT does not list a US-model application. In a US 240SX that has been swapped to an SR20DET, fitment depends on the flywheel and transmission used in the swap, so tell us the engine, gearbox and flywheel before you order. A 240SX still running the KA24DE needs a different ACT kit, such as the NX1-HDG6. Browse more in our rebuild kits section.
| Brand | ACT |
| Part number | NS1-HDG6 |
| Fits | ACT HD/Race Sprung 6 Pad Clutch Kit |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
ACT lists it only for the JDM SR20DET Silvia K (S13/S14), Silvia Spec-R (S15) and Bluebird. A US 240SX with an SR20DET swap may use it depending on the flywheel and transmission in the swap. A KA24DE 240SX needs a different kit such as the NX1-HDG6.
Both use the same six-pad sprung ceramic disc. NS1-HDG6 has the Heavy Duty pressure plate (475 ft-lb, light to moderate pedal), while NS1-XTG6 has the stiffer Xtreme plate for more torque capacity and a heavier pedal.
ACT rates the pedal as light to moderate with aggressive engagement and recommends it for high horsepower street or race use. Expect a quicker, more on-off engagement than an organic disc.
It includes the pilot bushing (PB1012), release bearing (RB810) and alignment tool along with the pressure plate and disc. A flywheel is not included.
ACT rates the kit at 475 ft-lb of torque capacity, 90 percent over the original SR20DET clutch.
