A heavy stock flywheel keeps an SR20DET smooth at idle, but it also stores extra inertia that dulls throttle response and makes the engine slower to climb and fall through the rev range. The NISMO Light Weight Flywheel (part number 12310-RS521) is the chromoly replacement specified for Nissan 180SX and Silvia S13 / S14 models with the SR20DET.
NISMO lists the unit weight at 6.52 kg versus 8.87 kg for the genuine flywheel, with inertial weight reduced from 1.849 to 1.577 kg·cm/sec². The disc is machined from SCM440H chrome-molybdenum steel and carries the NISMO logo. Ring-gear chamfering follows the factory process so the starter pinion still engages cleanly. Flywheel bolts and a press-fit dowel pin are included.
This flywheel was designed around NISMO single-plate clutch covers and discs. Used as a package, the combination cuts rotating inertia far more than a flywheel change alone and gives a more direct engagement than a dual-mass setup. It can be fitted in an OEM clutch layout, but NISMO intends it as part of a sports clutch system. Lighter rotating mass usually brings some extra gear noise or resonance at idle compared with the stock dual-mass unit, which is expected on this type of conversion.
At Terra Firma Automotive, we supply this genuine NISMO Light Weight Flywheel as the factory-developed SR20DET upgrade for S13 and S14 owners who want faster engine response without a generic aftermarket disc. Choose Terra Firma Automotive for authentic NISMO drivetrain components built for the turbo Silvia and 180SX.
- Genuine NISMO light weight flywheel
- Part Number: 12310-RS521
- Engine: SR20DET
- Material: SCM440H chrome-molybdenum steel
- Unit weight: 6.52 kg (OEM 8.87 kg)
- Inertial weight: 1.577 vs 1.849 kg·cm/sec²
- Designed for NISMO single-plate clutch systems
- Can be used with OEM clutch layout
- Factory-style ring-gear chamfer for starter engagement
- Includes flywheel bolts
- Includes press-fit dowel pin
- NISMO logo marked
- Improves throttle and rev response by cutting rotating mass
- More direct feel than a dual-mass flywheel
- Some added idle/gear noise is typical versus stock
- Available from Terra Firma Automotive
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