Mazda MX5 & RX8 LSD Upgrade Kits – Fuji and Super LSD Performance Boost

The Mazda RX8 and Mazda MX5 are true driver’s cars, but their factory Limited Slip Differentials (LSDs) suffer from a common weakness.

In the Mazda RX8 Super LSD and MX5 NB/NC Fuji LSD, the OEM design uses small friction cones behind the spider gears, pushed by weak springs. These cones are the Achilles’ heel of the factory LSD — they wear or break quickly, even on low-mileage cars, causing loss of traction and inconsistent performance.

At RacingDiffs, we developed two dedicated upgrade kits, each tailored to the exact dimensions of your LSD type.

• Mazda RX8 – Super LSD kit: Designed specifically for the RX8’s unique setup.

• Mazda MX5 NB/NC – Fuji LSD kit: Engineered to fit perfectly in the Fuji LSD used in MX5 NB/NC models.

Both kits replace the fragile friction cones with high-performance clutches and precision preload shims, along with 4x stronger springs to dramatically improve locking force. The result? Up to 4x better performance and vastly improved reliability over the OEM design.

Key Benefits:

• Custom-fit kits for Mazda RX8 Super LSD and Mazda MX5 NB/NC Fuji LSD.
• Replaces weak friction cones with durable clutches.
• 4x stronger springs for maximum locking power.
• Improved preload for better traction and cornering stability.
• Eliminates OEM failures, even on low-mileage cars.
• Ideal for spirited street driving, track days, and drifting.

No matter which Mazda you own, our LSD upgrade will transform your driving experience — delivering the grip, control, and reliability you expect from a true performance car.