• close ratio gears: the individual gear ratios are modified which allows the engine to maintain optimal powerband during shifting improving acceleration. Japanese version NSXes are equipped with transmissions with close ratio gear sets. Unlike the US version transmission, the car will not fall out of VTEC and optimal powerband. These gears can be installed into a US-spec transmission. Factory Honda parts from Japan are used.
• final drive gear set: As the power is transmitted through the transmission, the last set of gear set that transmits the power to the wheels is the final drive assembly. The final drive gear ratio is consistent for every gear the car is in. The US factory gear ratio is 4.06:1. The Japanese performance version of the NSX uses a 4.23:1 gear ratio. This gear set consisting of the countershaft, differential ring gear, and oil gear can be installed into a US-spec transmission. Factory Honda parts from Japan are used. The NSX-R spring plate and collar is included to set the pre-load to NSX-R spec. (more info)
  A higher ratio final drive gear set is available (4.44), however, it is only compatible with the OS Giken differential.
• differential: OS Giken offers an innovative Super Lock Differential which combines a helical gear type and clutch plate differential. The gear design allows maximum power to be transmitted to the inside wheel for improved corner traction while the 28-plate clutch pack allows for smooth torque transfer improving stability of the car and smooth operation. (more info)

• fully rebuilt US spec 5-speed transmission: all new factory syncros, bearings, spring rings, oil seals, and snap ring parts are replaced. Transmission is blueprinted and ready to be installed once delivered. Available for 1991-1996 5-speed manual transmissions.
• short-ratio: fully rebuilt transmission with Honda JDM Short Gear set installed. Available for 1991-1996 5-speed manual transmissions.
• short-ratio / NSX-R 4.23 final drive: fully rebuilt transmission with Honda Japanese Short Gear Set and 4.23 ratio final drive. Available for 1991-1994 5-speed transmissions. 1995-1996 transmissions require a torque control differential swap (please add $500).
• short ratio / OS Giken differential and 4.44 final drive: fully rebuilt transmission with Japanese Short Gear Set and OS Giken Differential with 4.44 final drive. Available for 1991-1996 5-speed manual transmissions.

specs