OS Giken has always been one of the most innovative high performance engine parts suppliers. For street and racing use, OS Giken can take special orders for one-off products to satisfy your specific needs. Please contact us for details.

RACING PERFORMANCE by OS Giken
Through the research and development of high performance engines, OS Giken realized that the production of durable, higher quality clutch systems is essential. OS multi plate clutches can transmit increased engine revs and torque output to the drivetrain without loss. The research and development has been continued since the first introduction the OS Giken clutch series in 1983. They are made from the highest quality materials, with durability that is second to none. The extensive model line up is sure to meet your needs and produce the best result for your engine.

Distinctive Features of OS Giken Multi Plate Clutches
Despite using smaller plate diameter, OS Giken clutches achieve efficient power transmission, along with better engine response. Revising the factory leverage mechanism of the diaphragm spring provides higher pressure on the clutch discs while reducing pedal effort. Ventilation holes are designed to reduce heat generated inside the clutch housing. These holes also let friction plate dust out of the clutch system, increasing reliability and safety. The OS Racing Clutch friction plates are made of heat-treated metal. These materials are carefully selected and alloyed so that the plates match with the flywheel and center plate material to improve durability.

About multi-plate clutches
Multi-plate clutches have been used in motorsport applications for many years. Now that productions cars are being tuned to much higher power levels in the past, multi-plate clutches have become popular with a wider range of users.

In the case of single plate clutches, performance can be improved by increasing the clamping load dramatically, or by using small ‘puck’ type contact patches on the clutch disc, in an aggressive friction compound (usually metal or ceramic). The problem with very heavy clamping load is not only a very heavy clutch pedal, but also excessive load on the throwout bearing and engine thrust bearings. Puck or ‘button’ type clutch discs can also make the car quite difficult to drive as they have a sudden take-up and may shudder if the driver attempts to slip the clutch. Of course performance single plate clutches do vary in quality, but these are problems often associated with them.

Multi-plate clutches offer some significant advantages over a typical single-plate upgrade. In the case of OS Giken multi-plate clutches, the clutch comes with a lighter chrome-moly flywheel and relatively small-diameter clutch assembly, improving engine response. The arrangement of the diaphragm allows high clamping force to be applied to the plates without increasing the pedal pressure to an excessive degree. The heat-treated metal compound on the clutch discs offers great durability and improved drivability compared to competition single-plate clutches. The clutch discs are virtually ‘full-face’ in design, with slots included to help dissipate heat.

OS Giken multi-plate clutches are rebuildable too, so their service life can be extended with a rebuild kit replacing the clutch plates, center plate(s) and pressure plate. The cover plate and spring diaphragm can also be replaced if needed. In the case of the ‘R’ series clutches (R2CD, R3C and R4C) the clutch discs are splined, so the hub does not need to be replaced when you change clutch discs. Or, alternatively if you change from one type of gearbox input shaft to another, only the hub needs to be replaced, rather than the entire clutch.

OS Giken are one of the only clutch manufacturers offering a quad-plate clutch system for production cars. This clutch is used by drag cars in Japan and other countries producing in excess of 1200hp. Despite handling such massive torque loadings it is well known for having the same drivability as the twin and triple-plate clutches. Achieving this sort of power handling and acceptable drivability from a single-plate clutch would be a very tall order indeed.