Fluidampr Steel Internally Balanced Viscous Damper – Nissan SR20DE / SR20DET | S13 / S14 / S15 Silvia, 200SX, 240SX | SFI 18.1 | 630931

The Fluidampr 630931 is the purpose-built viscous crankshaft damper for the Nissan SR20DE and SR20DET — one of the most widely used and highly developed four-cylinder engines in the JDM performance and drift community. Whether your SR20 is a naturally aspirated DE in a street build or a turbocharged DET in a dedicated S-chassis drift or time attack car, the Fluidampr controls crankshaft torsional vibration across the entire RPM range, protecting the rotating assembly from the harmonic loads that increase with every boost, power, and RPM increase your build demands. SFI 18.1 certified — sanctioned for competition use.

Note: The SR20DE/SR20DET was used across a wide range of Nissan platforms. Verify the 630931 is the correct part number for your specific chassis and engine variant using Fluidampr’s fitment guide before ordering — fitment may vary by market and production year.

Why the SR20DET Needs a Fluidampr at High Boost

The SR20DET is legendary in the S-chassis community for its tunability and the power levels it can support with the right supporting modifications — but every crankshaft experiences torsional vibration, and the SR20DET’s torsional loads increase significantly as boost, power output, and RPM ceiling rise. The factory elastomer damper is tuned for the stock engine’s resonant frequency at stock power levels. Increase boost, fit a larger turbo, raise the rev ceiling, or change the rotating assembly, and the factory damper’s effectiveness degrades — leaving the crankshaft, main bearings, rod bearings, and accessory drive exposed to uncontrolled harmonic vibration that accelerates wear and increases the risk of crankshaft fatigue failure under sustained high-load operation.

The SR20DE in naturally aspirated builds is equally affected — high-revving NA SR20 builds for time attack and circuit use push the engine to its RPM limits continuously, generating torsional loads the factory damper was never designed to manage at sustained high-RPM track use.

Fluidampr’s calibrated silicone fluid viscous damping technology controls torsional vibration across the full RPM range continuously — no narrow tuning band, no rubber to degrade, consistent protection regardless of power output or how the build evolves.

Key Features

• SR20DE and SR20DET Compatible: The naturally aspirated SR20DE and turbocharged SR20DET share the same crankshaft architecture — the 630931 fits both variants. Correct for street builds, drift builds, time attack cars, and any SR20-powered chassis running either engine variant
• Viscous Damping – Full RPM Range Protection: Calibrated silicone fluid viscous damping technology controls crankshaft torsional vibration across the entire RPM range — from idle to the SR20’s high-RPM ceiling. No narrow tuning band, no degradation over time, consistent protection regardless of boost level, power output, or rotating assembly changes
• Internally Balanced: Incorporates internal balance weights replicating the factory damper’s balance contribution to the SR20 rotating assembly — installs as a direct replacement without requiring rotating assembly rebalancing
• SFI 18.1 Certified: Meets SFI Specification 18.1 for harmonic dampers — sanctioned for competition use in SFI-governed racing series including drift, time attack, and circuit racing. Confirms the damper meets rigorous structural integrity standards for high-RPM, high-power competition operation
• Precision CNC Machined Steel: High-grade steel construction, precision CNC machined and balanced — corrosion-resistant black zinc finish with engraved timing marks for accurate ignition timing reference. Maintains dimensional stability under the thermal and mechanical loads of sustained track and competition use
• Reduces Wear on Critical Components: By controlling crankshaft harmonics, the Fluidampr reduces fatigue stress on the crankshaft, main bearings, rod bearings, and accessory drive — extending the service life of critical SR20 components on a build operating well beyond its original design envelope
• No Maintenance Required: Sealed viscous fluid chamber requires no servicing over the life of the damper
• Made in USA: Designed and manufactured in the United States. Trusted by leading SR20 engine builders and S-chassis competition teams worldwide

Fitment

• Nissan Silvia S13 — SR20DE / SR20DET (1988–1994)
• Nissan 200SX / Silvia S14 — SR20DE / SR20DET (1993–1998)
• Nissan Silvia S15 — SR20DE / SR20DET (1999–2002)
• Nissan 240SX S13 — SR20DE / SR20DET (SR20 engine swap applications)

The SR20DE/SR20DET was used across multiple Nissan platforms and markets. Verify the 630931 is the correct part number for your specific chassis, engine variant, and production year using Fluidampr’s fitment guide before purchasing. Fitment may vary by market (JDM vs USDM vs EUDM) and production date.

Specifications

• Brand: Fluidampr
• Part Number: 630931
• Type: Viscous Crankshaft Damper
• Construction: Steel
• Balance: Internally Balanced
• Damping Technology: Calibrated Silicone Fluid Viscous
• Finish: Black Zinc with Engraved Timing Marks
• Certification: SFI 18.1
• Maintenance: None Required
• Origin: Made in USA

Installation Note: Use a proper harmonic damper installation tool — never drive the damper onto the crankshaft snout with a hammer or impact, as this will damage the crankshaft thrust bearing. Torque the crankshaft bolt to the manufacturer’s specification. Professional installation recommended, particularly on high-power SR20DET builds where correct installation torque is critical to crankshaft snout integrity.