Spec SR20DET Stage 3+ Clutch Kit
The SPEC SN333F is a Stage 3+ clutch kit for the turbocharged SR20DET, the engine most S13 and S14 chassis owners end up running. If your SR20 swap or JDM Silvia slips when the turbo comes up, flares on the shift into third, or the stock-style disc is simply worn out after a season of drifting or launches, this is the kit SPEC positions between its daily-friendly Stage 2 and its race-only stages.
The SR20DET makes its power in a hurry once boost arrives, and a bigger turbo or a boost controller can push torque well beyond what the original clutch was sized for. A clutch slips when the clamp load and the friction of the disc can no longer hold the engine's torque. SPEC's Stage 3+ uses a carbon semi-metallic full-face disc; SPEC describes that material as giving long life, a high friction coefficient and good drivability. Because the face is full rather than segmented, engagement is more progressive than a puck disc, which matters on a street car that sees traffic.
For scale, SPEC rates the Stage 3+ version it builds for the S15 SR20DET six-speed (SN333F-5) at 610 ft-lb and lists the kit weight at 20 lb. SPEC also sells SN333F-760, a 240 mm upgraded-diameter version for the 240SX that must be run with a SPEC billet flywheel. The SN333F on this page is the base number without either suffix.
Pull in fourth gear from low rpm to full boost and watch the tach against the speedometer. If engine speed jumps ahead, it is slip. Check the hydraulics first: a weak master or slave cylinder or old fluid causes poor release and grinding, which is a different problem. Our slipping diagnosis guide covers the load test, and shift flare vs slip helps sort out other drivetrain complaints. If you are running the FS5W71C five-speed, our 240SX FS5W71C guide covers the gearbox side.
Our catalog data lists this kit for the 1989-1998 Nissan 240SX chassis (S13 and S14) with the SR20DET engine, which covers JDM-engine swaps as well as imported Silvia and 180SX cars. It is not for a 240SX still running the KA24 with its factory clutch; SPEC makes separate KA24 kits. The S15 six-speed with a dual-mass flywheel takes the SN333F-5, and the 240 mm big-disc setup takes the SN333F-760, so match the exact suffix to your flywheel and transmission. Swaps vary, so send us the chassis, engine, transmission and flywheel details before ordering and we will confirm. Other SR20DET options include the SPEC SN332 Stage 2 and SN333 Stage 3, and the full range is in our rebuild kits and clutch collection.
| Brand | SPEC |
| Part number | SN333F |
| Fits | Spec SR20DET Stage 3+ Clutch Kit |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
No. It is listed for the 240SX chassis with the SR20DET. A 240SX that still has the KA24 and its factory transmission needs a KA24 clutch kit.
SPEC lists the SN333F-5 for the S15 SR20DET six-speed with a dual-mass flywheel. Send us your flywheel details so we can confirm which suffix you need.
SPEC's Stage 3+ uses a carbon semi-metallic full-face disc for life, friction and drivability. It is aimed at cars that need more holding power but still see regular street use.
SPEC rates the Stage 3+ kit it builds for the S15 SR20DET at 610 ft-lb. SPEC does not publish a separate figure for the base SN333F number.
Resurface or replace the flywheel, fit a new pilot bearing, inspect the slave cylinder and fork pivot, and bleed the clutch hydraulics.
