Circle D GM Pro Series 10L90 Torque Converter

Circle D Specialties GM 245mm & 258mm Pro Series 10L90 Torque Converter

The Circle D Specialties GM Pro Series 10L90 Torque Converter is a top-tier, precision-engineered upgrade designed specifically for extremely high-horsepower GM vehicles equipped with the heavy-duty 10L90 transmission. The 258mm diameter offers a perfect middle ground—significantly reducing rotational mass for lightning-fast throttle response and explosive acceleration off the line, while maintaining highly efficient torque transfer, whereas the 245mm spins up more quickly. It features a cutting-edge CFD Modeled 5-Axis Billet Steel Stator Combination, allowing for optimal fluid dynamics, maximum efficiency, and perfectly dialed-in launch characteristics tailored to your specific naturally aspirated or power-adder build.

Built to dominate the track and survive massive power output, this Pro Series converter features a rigid billet steel front cover to completely eliminate flexing under heavy load. Crucially, it utilizes a heavy-duty Modular Clutch Pack Assembly with clutch pack isolators that provides an astonishing 2,000+ ft-lbs of holding capacity, combined with a Patent-Pending Flow Control Piston Design for absolute reliability during wide-open throttle (WOT) lock-up. Inside, the fins are fully furnace brazed and hand TIG welded for maximum structural integrity, spinning smoothly on a CDS Exclusive Deep Groove Ball Bearing. Note: Valve-Body modifications (Ratio-Tek RT-10L80-PRX) are recommended for optimal performance with this unit.

Key Features & Upgrades

• Designed specifically for GM 10L90 transmissions
• 245mm and 258mm diameter delivers a superior balance of rapid engine response and torque holding
• Modular Clutch Pack Assembly delivers an extreme 2,000+ TQ holding capacity
• CFD Modeled 5-Axis Billet Steel Stator for optimal efficiency and precise stall characteristics
• Patent-Pending Flow Control Piston Design and Clutch Pack Isolators
• Rigid one-piece billet steel front cover prevents flexing and ballooning
• Fully furnace brazed internals with hand TIG welded fins
• CDS Exclusive Deep Groove Ball Bearing for ultra-smooth, reliable operation
• Valve-Body Modifications Recommended (Ratio-Tek RT-10L80-PRX)

Specifications

• Application: Extreme High-Performance Street/Strip Torque Converter
• Transmission Compatibility: GM 10L90
• Converter Diameter: Optional 245mm and 258mm
• Construction: Billet Steel Front Cover, Furnace Brazed, Hand TIG Welded Fins
• Stator: CFD Modeled 5-Axis Billet Steel
• Clutch: Modular Clutch Pack Assembly (2000+ TQ Capacity)
• Options: Multiple Stall Speeds (2800 up to 5000 RPM) available

Notes

• Custom manufactured product built to your exact specifications.
• Estimated lead time: 3-4 weeks.