OS Giken OS-88 Sequential 6-Speed RB26 GTR Standard Ratio
OS Giken OS-88 Sequential 6-Speed RB26 GTR Standard Ratio is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
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
Can I return a product after install?
Once a product has been installed, used or fitted it is no longer returnable.
How long do I have to return a product?
Customers have 7 days inclusive from the day they receive their order to lodge a “Return Request” with ModsDirect. If the return form is approved (notification by email) the item must then be returned within 21 days. All returns must be trackable.
Please note that exchanges, refunds or credits will NOT be processed until the returned product(s) is received by ModsDirect.
Where do items need to be returned to?
After submitting a “Return Request” form, ModsDirect will be in touch via email to confirm details for return.
How do I return items?
All returns must be returned to ModsDirect by courier or post. All returns must be trackable. In some instances, ModsDirect may offer a return label.
What about restocking fees?
All returns will incur a fee of 15%. This is to cover fees incurred by ModsDirect for payment processing and handling. We are at the mercy of paying for services used at our website regardless of whether the order remains completed or reversed.
Who pays for return shipping?
All return shipping costs are the responsibility of the customer. However, if a customer has received the incorrect product, ModsDirect will cover return fees and provide a courier pickup at no cost to the customer.
Exchange, Credit or Refund?
If a customer requests a return, they may be eligible for either an exchange, credit or refund based on the nature of the return and product availability. If refunding, moneys will be returned to the customer via the original payment gateway used at checkout.
Can I drop a return off to ModsDirect?
Sorry, no in-store return option is presently available.
I damaged the packaging during unboxing, can I still return?
Unfortunately not. All packing materials must be in resalable condition for a return. Some minor damages such as a neat cut of a package seal may still be eligible for return. Please include a photo of the packaging with your Return Request form.
By purchasing from ModsDirect you agree to the Return Policy outlined above.
The “Vehicle Fitment” tab found on ModsDirect product listings are to be used as a guide ONLY. ModsDirect does not take responsibility for any misinformation on the Vehicle Fitment tab. The customer must ensure proper and correct fitment on their vehicle prior to ordering. If any errors are found in any product, you are encouraged to inform ModsDirect by clicking here.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.


