OS Giken OS-88 sequential 6-speed gearbox for Skyline GT-R Standard Ratio.
The OS-88 is designed to suit BNR32 and BCNR33 GT-Rs. Can also be used in BNR34 but a BCNR33 transfer case and prop shaft will need to be fitted.
This is a helical-gear dog-engagement gearbox designed for circuit racing use. The helical gears give relatively quiet operation so it is also suitable for street use, but the dog-engagement necessary for quick sequential shifting requires regular maintenance which is inconvenient for a street car.
The OS-88 uses much larger and stronger gears than a normal GT-R gearbox, giving it a power rating of 1500hp at the engine. The casing is also larger, most notably taller, so it needs a different gearbox crossmember (see crossmember in this category). It is also highly recommended to fit the optional direct shift kit, which uses a specially designed lever for shorter throw and brass bushings for much less slack in the gearshift.
The gearbox uses a 26-spline GM input shaft size (same as Holinger) so it needs a clutch with this spline. OS Giken has R3C triple and R4C quad-plate clutches available to suit.
This version of the gearbox (‘standard ratio’) is suited for street and circuit racing use. The tall first gear may not be suitable for drag racing (see option 2 ratios instead).
Gear ratios: 2.609, 1.934, 1.521, 1.210, 1.000, 0.852
All OS-88 Gearboxes are made to order please allow 4-5 months for delivery.