Blackline Limited Slip Differential - Mazda MX-5 NA NB Miata - 1994–2005

The Blackline limited slip differential for the Mazda MX-5 NA* and NB (1994–2005), also known as an LSD (Limited Slip Differential), improves traction by distributing torque between the two-wheel drive drive wheels based on available grip.

Its helical gear design allows the limited slip differential to transmit more torque to the wheel with the best traction. As torque increases, the gears exert pressure against the differential housing and generate the internal friction necessary for this torque distribution. The system can thus handle a significant difference in drive force between the two wheels, particularly during heavy acceleration when exiting a turn or when traction is limited.

Under light loads, the helical limited slip differential maintains smooth, progressive, and quiet operation. The wheels can continue to rotate at different speeds when necessary, particularly when cornering. This feature improves traction during spirited driving while maintaining handling suitable for on-road use.

The Blackline limited slip differential uses a parallel-axis helical gear architecture optimized to distribute forces. Its 5:1 torque split means that when one wheel loses traction, the wheel with the most traction can receive up to five times the torque transmitted to the spinning wheel.

As with any helical-gear limited slip differential, a minimum amount of resistance must remain on the wheel with the least traction to allow torque transfer. It is therefore most effective when both wheels remain in contact with the ground. This technology also works particularly well in conjunction with modern ABS systems.

The Blackline HLF030 limited slip differential is designed for Mazda MX-5 and Miata models from 1994 to 2005. It can also be installed on an MX-5 Mk1 1.6, provided that the differential housing, propeller shaft, and differential shafts from the 1.8 version are used. Its housing and gears are made of high-strength 8620 steel.

Technical Specifications of the Blackline Limited Slip Differential for Mazda MX-5 and Miata (1994–2005)

Manufacturer Part Number: HLF030
Quaife Application Match: NC
Type: Helical-gear limited slip differential
Vehicle compatibility: Mazda MX-5 and Miata NA and NB (1994–2005)
*Specific compatibility: Mazda MX-5 Mk1 1.6 with 1.8-liter drivetrain conversion
Parts required for MX-5 Mk1 1.6: Differential housing, propeller shaft, and differential shafts from the MX-5 1.8
Torque split ratio: 5:1
Housing and gear material: High-resistance 8620 steel
Mounting: Replaces the original differential on compatible models

Key Features of the Blackline Limited Slip Differential for Mazda MX-5 and Miata

• Torque split between the wheels based on available traction.
• Delivers more torque to the wheel with the best traction.
• Immediate and progressive reaction to changes in traction.
• Smooth, progressive, and quiet operation.
• No friction discs for reduced maintenance requirements.
• Power delivery that is easily controllable, especially during spirited driving and drifting.
• Housing and gears made of high-resistance 8620 steel.