• Performance Clutch
  • Close Ratio Gear Kit
  • Special Parts

    • DISCS

      Disc


      OS Giken utilizes full face metallic clutch plates to achieve high torque capacity from our clutches. This allows for us to use much softer diaphragm springs to achieve equal or better torque capacity compared to our competitors with substantially less pedal effort.

      CLUTCH COVER

      Clutch Cover


      Specially designed clutch cover contains a unique leverage mechanism for the diaphragm spring, resulting in a higher clamping load of the clutch disc(s) while also reducing pedal effort. These diaphragm springs combined with our special OS Giken Release Sleeves provide a much easier to operate clutch.

      CLUTCH HOUSING

      Clutch Housing

      Integrated ventilation holes reduce heat generated inside the clutch system and allows for friction plate dust to exit outside the clutch system, thus increasing reliability and safety. Both the clutch housing and flywheel are chemically heat treated to handle extreme conditions. Increased power output typically requires more torque capacity(friction) in order to hold. This often leads to more heat being generated.

      FLYWHEEL

      Flywheel

      Hardened steel alloy flywheels provide superior durability and life than aluminum flywheels, which also results in quicker and predictable engine response. We develop our own flywheel design to maximize our design and engineering philosophies into a no-compromise, complete clutch assembly.

    • GEAR RATIOS

      Gear Ratios


      OS Giken carefully research each engine and intended racing application to formulate the most suitable gear ratios to maximize the engine’s potential. The gears are intended to keep the engine operating at its peak optimal power-band thus allowing the vehicle to continue to accelerate as efficiently as possible.

      GEAR PROFILE

      Gear Profile


      Gears are helical-cut rather than straight-cut in order to maintain a quiet operation as well as increased reliability for racing.

    • OS88 SEQUENTIAL TRANSMISSION

      Sequental Transmission

      OS Giken has designed this sequential transmission to specifically fit the engine characteristics of Nissan's RB26DETT engine to allow it to perform to its maximum potential. To withstand the incredible punishment a race tuned RB26DETT is capable of delivering to the drivetrain, it engineered and manufactured a reinforced transmission case made from high-quality forged materials. By optimizing gear size and settings, we have increased the gear axis distance to 88mm, resulting in a 6-speed sequential transmission capable of withstanding up to 1500 horsepower.

      In addition, unique dog link mechanism enables accurate shift changes, as well as provides a positive shift feel. Each unit is hand made and thoroughly examined to our exacting standards prior to shipment to ensure the highest quality. The OS88 is comprised of synchro-less helical cut gears and is the perfect complement for a tuned RB26DETT motor. It can be ordered with 4 different sets of gear ratios to suit almost any engine power profile and racing purpose. OS Giken also offers an assortment of optional parts to provide the ultimate solution for the serious racer.

      RB30 OS-E2996 AND RB315 OS-E3138

      RB30 OS-E2996 AND RB315 OS-E3138

      By utilizing our engineering knowledge and proven manufacturing capabilities, our world-famous OS Giken RB30 engine begins as a brand new Nissan RB26DETT N1 block, which is then stroked and bored to achieve 2996cc of displacement. For competition use only, we also offer a higher performing OS-RB315 engine. With the supporting modifications and proper tuning, this motor is capable of reliably outputting over 1400hp!