BorgWarner 179140 EFR B1 6258 Turbo Supercore Assembly

The BorgWarner EFR 6258 Supercore (part number 179140) is the smallest and fastest-spooling turbocharger in the ultra-efficient EFR (Engineered For Racing) lineup. This B1 frame supercore assembly is designed for high-performance applications supporting 225-450 horsepower in single turbo configurations, or 400-700+ horsepower in twin turbo setups.

Key Specifications:

• Compressor wheel: 62mm outer diameter with 49.6mm inducer
• Turbine wheel: 58mm low-inertia Gamma-Ti titanium construction
• Maximum airflow: 44 lb/min
• Horsepower range: 225-450 HP (single turbo) / 400-700+ HP (twin turbo)
• Bearing housing: Cast iron construction

Advanced Features:

• Dual ceramic ball bearing assembly with metal cage for ultra-low friction and maximum durability
• Forged Milled Compressor Wheel (FMW) with extended tip technology for improved efficiency
• Integrated Compressor Recirculation Valve (CRV) built into housing
• Integrated Boost Control Solenoid Valve (BCSV)
• Compressor cover with speed sensor mounting provisions
• Watercooled center section with 14mm banjo bolt fittings (watercooling recommended but not mandatory)
• Double seals on both turbine and compressor ends for extreme durability
• Built-in oil control orifice - no external restrictor required

The low-inertia Gamma-Ti turbine wheel is optimally matched with the FMW compressor wheel for maximum response and fastest spool-up. The compact design fits in tight engine bays, making it particularly suitable for twin turbo V6 applications. This supercore is ideal for autocross, rally, drift, road racing, and street-driven performance vehicles with small displacement engines.

Note: This is a supercore assembly only. Turbine housing, clamp plate hardware, wastegate, and actuator are sold separately. All turbine housing mounting hardware, clamp plates, and cap screws are included with the supercore.