Description

The HKS CRANK DAMPER PULLEY serves as a specialized harmonic balancing component engineered exclusively for the HKS VR4.3L engine kit. It is specifically designed to mitigate torsional vibration inherent to the extended-stroke crankshaft configuration. Developed through collaborative engineering with ATI, this purpose-built damper pulley directly addresses the unique resonance characteristics of the 4.3L displacement engine. Consequently,

it reduces peak torsional values that occur at specific harmonic frequencies. This enhances overall engine smoothness, component longevity, and power delivery consistency. By optimizing damping characteristics specifically for the increased stroke and modified rotating assembly of HKS’s 4.3L platform, this component provides critical vibration control. Standard or generic dampers cannot adequately address this.

Product Highlights

🎯 VR4.3L-Specific Engineering Through Collaborative Development
Developed jointly with ATI—a recognized leader in harmonic damping technology—this damper pulley features tuning parameters specifically matched to the HKS VR4.3L engine’s unique resonance characteristics. Unlike universal or generic dampers, this component’s specifications were determined through actual torsion measurement during engine bench testing.

Therefore, it provides optimized performance precisely for the extended 99.0mm stroke and increased displacement of HKS’s 4.3L configuration.

⚙️ Targeted Torsional Vibration Reduction at Critical Resonance Points
Engineered to reduce peak crankshaft torsion occurring at specific harmonic frequencies, this damper pulley directly addresses the increased torsional forces. These forces are generated by the longer-stroke crankshaft operating within an elevated 7,400 RPM range. By attenuating these harmonic vibrations, it not only enhances engine smoothness but also reduces stress on connected components including timing systems, accessory drives, and the crankshaft itself.

🔧 Maintained Compatibility with Factory & HKS Accessory Systems
Featuring an identical V-belt pulley diameter to the factory component, this damper maintains full compatibility with both factory accessory systems and HKS Fine Tune V-belts. This thoughtful design consideration ensures seamless integration without requiring modifications to alternator, power steering, or air conditioning systems. It also allows enthusiasts to utilize HKS’s premium belt offerings for optimal accessory drive performance.

🔄 Optimized Specifically for Enhanced 4.3L Displacement Characteristics
Recognizing that the extended stroke and increased displacement of the VR4.3L kit create distinct torsional characteristics, this damper represents a necessary complement rather than an optional accessory. It differs from both factory and generic aftermarket applications. Its development acknowledges that proper harmonic control is essential for realizing the full performance and reliability potential of the increased displacement platform.

Technical Specifications

Product Name: CRANK DAMPER PULLEY

Model Code: 24998-AN001

Compatibility: Exclusively designed for the HKS VR38 4.3L engine kit in Nissan GT-R R35 (VR38DETT, 07/2007 onwards). Made-to-order production ensures precise specification matching.

Primary Function: Reduction of crankshaft torsional vibration peaks occurring at resonance points specific to the 4.3L displacement configuration.

Development Methodology: Joint development with ATI utilizing actual torsion measurement data from engine bench testing to determine optimal damping specifications.

Design Features:

• Pulley Diameter: Matches factory specification for complete accessory system compatibility

• Belt Compatibility: Supports use of HKS Fine Tune V-belts for optimized accessory drive performance

• Construction: Premium materials and precision balancing for reliable high-RPM operation

• Application Specificity: Tuned exclusively for the resonance characteristics of the 99.0mm stroke crankshaft

VR4.3L Kit Reference Specifications:

• Bore: 95.5mm (maintained from factory)

• Stroke: 99.0mm (increased from factory 88.4mm)

• Displacement: 4,255cc (12% increase over factory 3,799cc)

• Allowable RPM: 7,400 rpm (enhanced from factory 7,000 rpm)

• Compression Ratio: 8.6:1 with 0.8mm head gasket

Performance & Engineering Philosophy

Goal: To provide optimized harmonic damping specifically tailored to the unique torsional characteristics of the HKS VR4.3L engine configuration, thereby reducing vibration-induced stress, enhancing component longevity, and improving overall engine refinement within the enhanced performance envelope.

Focus: Precise resonance frequency matching through collaborative development and empirical testing; maintained compatibility with existing accessory systems; and recognition that increased displacement and stroke fundamentally alter harmonic behavior requiring specifically tuned damping solutions rather than generic alternatives.

Installation & Integration Considerations

🔧 Mandatory Companion to VR4.3L Engine Applications
This damper pulley is not merely recommended but essentially required for proper operation of HKS’s 4.3L displacement engines. Accordingly, it should be viewed as an integral component of the complete 4.3L system rather than an optional accessory. Professional installation ensures proper torque specification and alignment for optimal performance.

⚠️ Critical Compatibility & Application Notes:

• Specific Application: Designed exclusively for HKS VR4.3L engine configurations; therefore, it is not suitable for factory displacement engines or other aftermarket displacement variations

• Made-to-Order Production: Manufacturing processes ensure precise specification matching to current 4.3L kit characteristics

• Accessory System Verification: While maintaining factory pulley diameter, proper belt tension and alignment should be verified during installation

• Timing System Considerations: May influence timing characteristics slightly due to altered torsional behavior; therefore, comprehensive tuning verification is recommended

🎯 Primary Performance Benefits:

• Vibration Reduction: Decreased torsional peaks at critical harmonic frequencies specific to the 4.3L configuration

• Component Longevity: Reduced stress on timing components, accessory drives, and crankshaft bearings

• Power Delivery Consistency: Smoother rotational characteristics potentially enhancing power measurement accuracy and delivery consistency

• Accessory System Stability: Improved stability for alternator, power steering, and air conditioning operation under varied RPM conditions

Strategic Advantages & Technical Rationale

📊 Empirically Derived Rather Than Theoretically Specified
Through actual torsion measurement during engine bench testing, this damper’s specifications were determined empirically rather than through theoretical calculation alone; consequently, it addresses real-world harmonic behavior rather than idealized models.

🔬 Recognizing Displacement-Specific Harmonic Characteristics
The development of this dedicated component acknowledges a fundamental engineering reality. Increasing stroke by 12% (from 88.4mm to 99.0mm) significantly alters crankshaft torsional behavior and resonance frequencies. Therefore, it requires specifically tuned damping rather than relying on factory or generic solutions.

🤝 Collaborative Expertise Integration
Partnering with ATI—a specialist in harmonic damping with extensive motorsport and performance application experience—ensures that this component benefits from focused expertise in vibration analysis and attenuation. This collaboration complements HKS’s engine design capabilities with specialized damping knowledge.