Close Ratio Gear Kit for Mazda FD3S RX-7

OS Giken Close Ratio Gear Kits are carefully researched and designed for each engine’s 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. || Each OS Giken gear kit component is designed and created from high-quality forged materials, and then undergoes hard shot peening, resulting in increased strength and durability. The gears are helical-cut, rather than straight-cut, to maintain a quiet and smooth operation, accomplishing comfort for street driving as well as reliability for racing.