Description

The OS-FR5 and OS-FR7 sequential gearboxes are specifically designed for use in JDM sport compact and roadster vehicles.

The series name “FR” or OS-FR indicates the vehicle-specific front-engine, rear-wheel drive application for this transmission series. The OS-FR series sequential gearboxes are designed with a teardrop transmission housing and top-mounted gear lever for easy mounting in the limited transmission tunnel space often found in compact FR vehicles. A few examples of vehicles suitable for the OS-FR series transmission are Mazda MX-5 (NA/NB), Mazda RX7 (FD) or Honda S2000.

OS-FR5

The OS-FR5 is a 5-speed or sequential gearbox iteration of the OS-FR series designed to handle high torque and power while staying within the spatial constraints of compact FR vehicles. Developed through intensive testing, the FR5's dog-ring and gear design enables relatively low shifting efforts due to its torque capacity. Crafted with carefully selected raw, forged materials, the OS-FR5 can handle up to 575 ft/lbs of torque.

OS-FR7

The OS-FR7 is the very first 7-speed sequential gearbox in Japan. Unlike common designs where there is a direct drive in the transmission, the FR7 does not have a direct drive due to a unique drop-gear design. The drop-gear design minimizes shifting effort and enables fast and precise shifting. In addition to ease of shifting, the staggered 7-speed transmission in the FR7 allows the vehicle to easily stay in the power band regardless of engine characteristics. Crafted with carefully selected raw, forged materials, the OS-FR7 can handle up to 430 ft/lbs of torque.

FR5 & FR7 Gear Ratios