Fluidampr 630931 Nissan SR20DE SR20DET Viscous Damper SFI 18.1 Internally

Vehicle Fitment

• 1995-1998 Nissan 200SX (SR20DE, 2.0L I4)
• All Nissan SR20DET turbocharged applications, including:
• 1989-1994 Nissan 180SX / Silvia S13 (SR20DET)
• 1993-1998 Nissan 240SX / Silvia S14 (SR20DET swap - factory in JDM/RHD markets)
• 1999-2002 Nissan Silvia S15 (SR20DET)
• 1990-1994 Nissan Pulsar GTi-R (SR20DET AWD)
• 1990-1996 Nissan Bluebird U13 (SR20DET)
• Additional SR20DE applications with confirmed fitment: verify crankshaft and pulley compatibility for non-200SX SR20DE platforms before ordering

Fitment Notes

• The 630931 is designed for all SR20DET applications and for the 1995-1998 SR20DE as used in the Nissan 200SX. The SR20DET fitment covers both JDM/RHD and any LHD/swap applications using the SR20DET engine. Confirm crankshaft snout compatibility and pulley belt routing for your specific chassis and engine configuration before ordering.
• The 6.375" O.D. matches the stock SR20 OEM pulley diameter, maintaining factory accessory belt routing and alignment with factory or aftermarket A/C compressor, power steering pump, and alternator pulleys. No belt length change is required when replacing the OEM damper with the 630931.
• Because the Fluidampr damper is heavier than some lightweight aftermarket competitors, verify pulley clearance and belt alignment if using non-OEM accessory drive configurations or aftermarket underdrive pulleys.
• This is an internally balanced damper - it is designed for the SR20DE/DET's internally balanced rotating assembly. No external counterweight is required or present.
• SFI 18.1 certified - required for compliance in many sanctioned road racing, drift, and time attack classes that mandate SFI-spec harmonic dampers. Verify current rulebook requirements for your specific sanctioning body.
• A harmonic balancer installation tool is required for installation. Do not hammer or press the damper onto the crankshaft snout without a proper installation tool - this will void the warranty and can damage the damper housing.

Features

• Viscous damper technology with measured performance improvement - dyno-based crankshaft torsional vibration analysis conducted by Vibratech TVD (Fluidampr's parent division) at Jimmy Oakes Garage in Wallingford, CT showed an average 12% reduction in crankshaft torsional vibration amplitude across the full RPM range compared to a new, unaged OEM SR20 elastomer damper. This means measurable improvement even against a brand-new OEM unit, not just against a degraded one.
• Broad RPM range protection - unlike OEM rubber-bonded elastomeric dampers, which are frequency-tuned to control torsional vibration at a single critical RPM point, the Fluidampr viscous design uses an inertia ring suspended in high-viscosity silicone fluid to continuously dissipate torsional energy across the entire operating RPM range. This is critical for modified SR20DE and SR20DET engines, where increases in compression, boost, camshaft duration, or rotating assembly changes shift the engine's natural torsional resonance frequency away from the OEM damper's tuned point.
• 6.375" O.D. stock-matched diameter - the damper is machined to the OEM SR20 pulley outer diameter, preserving factory accessory drive belt geometry without requiring belt length changes, pulley spacers, or accessory drive modifications. This is an important practical advantage over some aftermarket dampers that require accessory drive reconfiguration.
• Precision CNC machined high-grade steel construction with corrosion resistant black RoHS finish - the steel housing and internal inertia ring are CNC machined and computer zero-balanced from the factory. The corrosion-resistant black RoHS-compliant finish with laser engraved timing marks provides permanent, precise ignition timing reference and long-term durability in the underhood environment.
• No tuning or maintenance required - the sealed viscous damper design requires no adjustment, fluid service, or periodic inspection for the life of the damper. The silicone fluid remains stable across a wide operating temperature range.
• SFI 18.1 certified - meets the Society of Fire Institution's specification 18.1 for crankshaft dampers used in racing applications, required for compliance in many sanctioned racing classes.
• Made in USA - designed, machined, and assembled at Fluidampr's Springville, NY facility by Vibratech TVD, whose parent company designs and manufactures viscous dampers for motorsport, passenger car OEM, heavy-duty diesel, marine, and defense industry applications.

Specifications

• Part Number: 630931
• Product Type: Viscous Performance Harmonic Damper
• Engine Fitment: Nissan SR20DE (1995-1998) and Nissan SR20DET (all applications)
• Outside Diameter (O.D.): 6.375" - matches OEM SR20 pulley diameter
• Balance Type: Internally balanced
• Construction: Precision CNC machined high-grade steel
• Finish: Corrosion resistant black RoHS; laser engraved timing marks
• Certification: SFI 18.1
• Torsional Vibration Reduction: 12% average vs. new OEM damper (Vibratech TVD dyno testing)
• Maintenance: None required
• Manufacture: Made in USA (Springville, NY - Vibratech TVD / Fluidampr)
• Release Date: December 2025
• Warranty: Manufacturer's limited warranty against defects in materials and workmanship

Included Components

• 1x Fluidampr viscous harmonic damper (steel, black RoHS finish, laser engraved)
• Note: Mounting hardware and installation tool are NOT included. A harmonic balancer installation tool is required - do not hammer the damper onto the crankshaft snout.

Product Description

The Fluidampr 630931 is a viscous performance harmonic damper for Nissan's SR20 engine family, covering the SR20DE (1995-1998 Nissan 200SX) and all SR20DET turbocharged applications globally - including the Silvia S13, S14, and S15 platforms, the 180SX, the Pulsar GTi-R, and the Bluebird. Announced in December 2025, the 630931 was developed with crankshaft torsional vibration analysis conducted by Vibratech TVD (Fluidampr's parent company) in collaboration with Jimmy Oakes Garage, with dyno testing demonstrating an average 12% reduction in torsional vibration amplitude across the RPM range compared to a brand-new OEM SR20 elastomer damper. The SR20 platform's popularity in grassroots drifting and street performance, combined with the wide range of modifications applied to these engines, made it a natural target for Fluidampr's engineering program.

The viscous operating principle is the core advantage of the Fluidampr over both the OEM elastomer unit and most lightweight aftermarket pulleys. OEM elastomeric dampers absorb torsional energy at a single tuned frequency - effective at stock power levels and with the factory rotating assembly, but increasingly mismatched as boost, compression, camshaft timing, or rotating assembly components change. The viscous design uses a precision-fit inertia ring suspended in high-viscosity silicone fluid inside a sealed CNC machined steel housing to dissipate torsional energy continuously across the full RPM range, self-adapting to the engine's current torsional frequency without requiring tuning, adjustment, or maintenance. The 6.375" O.D. matches the OEM SR20 pulley diameter exactly, preserving factory accessory belt routing without requiring belt changes or accessory drive modifications.

The 630931 is SFI 18.1 certified, machined in a corrosion-resistant black RoHS finish with laser engraved timing marks, and manufactured in the USA at Fluidampr's Springville, NY facility. A proper harmonic balancer installation tool is required for installation - pressing or hammering the damper onto the crankshaft snout without a dedicated installation tool will void the warranty and risks damaging the damper housing or crankshaft snout. The 630931 is covered by Fluidampr's manufacturer's limited warranty against defects in materials and workmanship.