STILLEN Nissan 370Z [Z34] / Infiniti FX35, G35, G37, Q40, Q50, Q60 Underdrive Performance Lightweight Crank Pulley - 400370

The STILLEN Underdrive Performance Lightweight Crank Pulley is designed for enthusiasts looking to maximize power gains by reducing both rotating mass and accessory drag. By underdriving the factory accessories by approximately 20%, this pulley reduces parasitic losses, allowing more engine power to reach the wheels.

Machined in-house by STILLEN from 6061 aerospace-grade billet aluminum, this underdrive pulley is significantly lighter than the factory steel unit while maintaining OEM timing marks, belt alignment, and long-term durability. Precision broached keyways and stainless steel wear sleeves at seal contact points ensure reliability under high RPM and spirited driving conditions.

This pulley is engineered specifically for dual throttle body Nissan and Infiniti engines and is ideal for street and performance builds where maximum efficiency and throttle response are desired.

Fitment:

• Nissan 370Z (Z34)
• Infiniti FX35
• Infiniti G35
• Infiniti G37
• Infiniti Q40
• Infiniti Q50
• Infiniti Q60
• Fits RWD & AWD models
• Engine Requirement: Dual Throttle Body engines only
• Emissions Notice: Not for sale or use in California

Key Features:

• Underdrive lightweight crank pulley
• Approximately 20% underdrive for reduced parasitic drag
• CNC-machined from 6061 aerospace-grade billet aluminum
• Manufactured and balanced by STILLEN for precision performance
• Stainless steel sleeves at main seal contact points
• Maintains OEM timing marks and keyway alignment
• Precision balanced for smooth operation at high RPM
• Designed for performance-focused street and track builds

Technical Details / Performance:

• OEM pulley weight: 4.72 lbs
• STILLEN pulley weight: 0.99 lbs
• Weight reduction: Over 80% lighter than stock
• Estimated gains: Up to 10+ WHP (results may vary)
• Approximate underdrive: 20%
• Material: 6061 billet aluminum
• Shorter belt required (sold separately): STILLEN #400370B
• Part number: 400370