The GT L.S.D. Series is a limited slip differential tested in actual battle in the Japan GT series. It was used in the 2002 season by the GT500 XANAVI NISMO GT-R and the GT300 Daishin Advan Silvia, and currently is preferred by user in production car-basis motorsports such as D1 Grand Prix, tuning car racing and Super Taikyu. Street use, circuit attack and drifting, Please select for your particular use.

Example of kit contents: for the 38420-RSS20-B5, all parts listed below are included in the L.S.D. installation kit, priced at \55,725 (tax included)

To increase L.S.D. performance, it's easy to make a major increase in plate size or increase the number of plates. But to have the precise number of plates slip within the narrow space of an L.S.D. case is extremely difficult. As NISMO began developing the GT L.S.D., it very seriously considered the plates, gears and case, and developed specifications for the most precise movement of every part. The GT L.S.D. series was not simply developed by increasing plate size or the number of plates. From slip to lock, only the most suitable specifications for the most precise, smooth slip were used, so that we could provide the highest possible quality L.S.D. The high-quality, high-performance GT L.S.D. series, which overwhelms the competition, has been created for those who know the performance of existing L.S.D.s.

The performance of an L.S.D. is naturally tied to the locking of left and right shafts-but do you really to what extent the actual locking performance (generation torque) is transmitted to the shafts? In the case of imprecisely manufactured L.S.D.s, the generation torque delivered to the left and right shafts can be quite different. With this imbalance of generation torque to the left and right, it can be difficult to keep the vehicle in good position during acceleration or braking (in case of 2way), forcing unnecessary steering operations. In this case, there is no sense in installing an L.S.D.; it will also make suspension and brake setting difficult as well. The GT L.S.D. series brings together both high quality and large capacity, with uniform torque at both the left and right shafts. The high traction performance of the GT L.S.D. series also allows for the best setting of both brakes and transmission.

In the performance graph at the following, the characteristics from the point the L.S.D. becomes effective to the locked condition are shown. While the generation torque is uneven to the left and right in the L.S.D.s of other manufacturers, it is clear that the GT L.S.D. distributes even generation torque to both shafts. When generation torque is not evenly distributed to the left and right, acceleration on low-μ roads, such as in rainy conditions, often results in the car moving to one direction or the other. This negative tendency may force driver to make unnecessary steering actions like adjusting the angle control when cornering to the left or the right. This difference in the cornering feeling either to the left or right also results in the need for further setting of the suspension.
This makes it easy to understand that the uniform generation torque provided by the GT L.S.D. means superior controllability.
In the racing world, it's common knowledge that a precisely operating L.S.D. is definitely needed in order for subtle tuning of the suspension and brakes. It was with this thinking, and with our experience, that the NISMO GT L.S.D. was born.

The biggest disadvantages in increasing the size or number of plates in the L.S.D. is the reduced plate teeth size and groove area of the side gear and case, resulting in poorer slip stability, and a reduction of plate strength due to thinner plates. In the GT L.S.D. series, plates with 16 outer teeth and eight inner teeth-manufactured to the highest precision levels possible-and superior manufacturing facilities and procedures provide the highest slip performance. Rather than focus on securing an inefficient oil line, we focused on stable slip performance-and the result is this L.S.D. The plates assembled in the L.S.D. slip in the same way as a rag clutch, shifting from slip to lock. If the manufacturing precision of these internal parts is low, however, the plate falls into a misshift condition where the plate is dragged around by only partial contact, so even if locking is desired a repeated cycle of slip-lock-slip-lock occurs. Locking performance is poor, with a faster rise in gear oil temperature and a reduced L.S.D. lifespan due to plate judder vibrations.

In an L.S.D., a torque is generated when the pressure ring opens, and as the plate moves from slip to lock, producing the "effect" which is the function of an L.S.D. In the graph at the following, the gray line representing the L.S.D. of another manufacturer is wide, where the blue GT L.S.D. line is thin and straight. This wide line is evidence that the plates are causing slip to occur, and that the L.S.D. is barely reaching the locked state. The fact that unnecessary plates are slipping is something that should never happen in the operation of an L.S.D., and has a very negative effect on driving. You can hear it in the driver's comments: "Angle control is unstable; something's strange," "I could enter into drift fine, but I couldn't hold it," or, "The variation of oversteering and understeering is too harsh" On the other hand, the very straight line of the GT L.S.D. shows that it is working very precisely from the time of acceleration moving from slip to lock without unnecessary slippage, and also in accel-off as it moves precisely from lock to slip. The installation of the GT L.S.D. is a shortcut to improved driving technique and the vehicle setting.