Welcome to Os Giken

Os ClutchOur drive train products provide winning results and enable your vehicle's high performance engine to deliver power where it counts.

1975, OS Giken made it's memorable entry into the racing world with the its unparalleled Four Valve DOHC TC16-MAII/TC24-B1 engine and firmly established itself as one Japan's most innovative race engineering companies.

Because all of OS Giken's designs and concepts are based on sound engineering and quality manufacturing, their reputation for reliable performance and durability is unparalleled.

Consequently, OS Giken’s drive train products are commonly the first choice for professional race teams in Japan, because in order to finish first you must first finish the race.


Os Clutch

Os Super Lock LSD

Os Close Ratio Gear Kit

Os Special Parts

Our Clutch/Flywheel packages increase transmission efficiency and engine response. All clutches and flywheels are crafted using carefully selected materials to provide you with the highest quality and durability.

Our patented design is a revolutionary breakthrough in clutch type limited slip differential design and allows us to have up to twice the friction plates compared to conventional designs. Our quality craftsmanship and original design enables 100% full locking as well as unparalleled durability.

For those seeking better race results. Our gear kits are made from carefully selected materials and every gear is forged for extra strength. Our gear ratios have been determined through extensive research and race track testing

We understand that the creation of a race car often extends beyond the normal limitations of "off the self" parts. Utilizing our accumulated knowledge and racing experience, we have engineered and produced a wide arrange of custom performance parts for various applications.


New BNR34 Democar!
OS is now making a BNR34 demo-car for their Russian customer, with RB315. For more information and car specifications, please refer the following website: