OS Giken Super Lock Limited Slip Differential Unit, BMW E9x M3

The OS Super Lock LSD is the culmination of over four years of extensive research and development leading to a revolutionary LSD design. With the capacity to house an unprecedented number of friction plates (up to 28 plates in total) and combined with our patented lock timing system; the Super Lock LSD is able to achieve complete lock in a progressive, smooth, and quiet manner. This effort translates to quick lap times and repeatable tuning and performance.

Superior Design

• Miniaturized pressure ring and a superior spline-through-side-gear design allows for fitment of more friction plates (up to 2x as many as competitors versions), offering true 100% lock capability.
• Patented pressure ring design allows for smooth, progressive locking.
• LSD case has a relief cut-out for the cone spring, resulting in minimal cone spring degradation and enhanced durability.

Superior Construction

• All components are chemically heat treated for maximum durability
• All components are constructed from a high-grade steel alloy
• Gears are raw-forged for maximum strength
• Clutch disks are precision-machined simultaneously on both sides to extremely tight tolerances resulting in minimal warpage.
• LSD case is machined from a single billet piece to ensure uniformity.

Superior Overall Performance

• The OS LSD standard spec allows for low preload while still retaining a fully progressive 100% lock capability; basically, the vehicle will feel like driving on an open diff in slow turns / street driving, but can still transmit maximum power to the drive wheels under load.
• Operation is ultra quiet, and the progressive locking allows for smooth, predictable locking. Especially when replacing an open diff, equipping OS LSD will completely improve the driving experience while maintaining everyday drivability.
• Due to the precision manufacturing, high-grade materials, and unique design, a break-in period nor rebuild is required for OS Giken LSD’s. OS LSD is purposefully over-engineered to offer the best performing, most durable clutch-type LSD available.
• Aside from the performance advantage and stock-like feel at slow speeds, vehicles equipped with OS LSD are more stable in all road/weather conditions, allowing for a safer driving experience.

Tunability

• Initial torque can be adjusted by using thicker / thinner cone springs
• Lock progression timing can be adjusted by using stiffer / weaker pressure ring springs, allowing the progression of full lock to be fine-tuned to the vehicle/driver.
• Ramp angles can be customized by swapping the pressure ring and iron cross for even more tuning possibilities.
• TCD spec disks can be installed for increased oil cooling and even smoother operation.