We've added the needed engine and additional horsepower components to our drift car build up. Our Tanabe suspension is as buff as it gets but believe it or not, we are two steps away from drift status. To say it's impossible to drift with a peg-leg differential is nonsense, but drifting with a limited slip differential not only makes it easier to kick it out, it also allows you to put the car sideways on deceleration with the right setup. Rather than just show you the whole install on our project car, we decided to give you a rundown on how and why a limited-slip differential works. We are also going to tell you how to adjust the new U.S.-spec Kaaz unit.
In the past-well, more like six months ago-the Kaaz LSD was a factory replacement for the J-spec Nissan S-13, 14 and 15 vehicles. The main difference between the U.S. and Japan spec diffs were their input shafts (stub ends). J-spec stub ends were required to put this diff into a U.S.-spec car. The main reason was the JDM stub axle was much shorter as well as having the necessary C clip ring installed on it. For quite some time now Newport Exotic Cars, authorized dealer for Kaaz, has been selling the J-spec diff for most Japanese imports. President, Ray Nakadate, has been pushing for Kaaz to build a factory replacement differential to cater to the U.S. market. This would mean redesigning the end gears to accept a U.S. stub axle rather than swap in the J-spec pieces. Ray asked for years and finally Kaaz has delivered. Not only did Kaaz design the differential to except U.S. axles but they also ended up giving the LSD a completely new design. To start with, the old unit runs four discs per side while the new unit crams in eight discs per side. This allows much more surface area for contact, giving the new LSD much more grip for high-horsepower engines. Determining the lock up is all in the sequence of the discs. To change the amount of lock up requires jumping various inner spline discs to mesh with some of the outer spline units. Adding more ease in the installation, the new Kaaz unit also comes with new differential bearings pre installed and include the bearings' outer race.
Many people often wonder if they need a one-, one-and-a-half- or two-way differential for drifting. To get the best results it's always best to go with a two-way. Keep in mind, it's also much easier to lose control on a two-way because a two-way can lock up on acceleration and deceleration. What determines the amount of lock up on an LSD are its internal hubs that encase the spider gears. Looking at the two halves side by side, you will notice four small open triangle sections when the two halves are aligned together. In between the halves ride the spider gears and spider gear shaft. A common rule of thumb is if the shape of the openings is triangular, it is a one-way LSD. This means the LSD locks up only under acceleration. If the opening is teardrop in shape it's considered a one-and-a-half-way. This will allow full lock up under acceleration and half lock up under deceleration. If it is diamond shaped, then the LSD will engage full lock up in acceleration and deceleration. For our drift car build up we used what the pros use and went with a two-way LSD.
Now when we talk lock up, the LSD work a lot like a triple disc clutch in a sense that there is a pressure plate, disc with floater plates, flywheel and even something resembling a clutch pedal. On both sides of the LSD you would have the pressure plate which on an LSD would be the diaphragm spring. The diffs' hubs are the flywheels and the clutch pedal would act as the spider gear shaft in between the hubs. Now one difference between a typical clutch set up and LSD is that by simply moving certain plates in a different order, you can achieve a different type of lock up. For instance, if we were to jump one plate out of sequence we would be able to establish 75-percent lock up. Jump another and you would get 50 percent. For our application, we decided to leave the LSD the way it comes out of the box at 100-percent lock up as most drift racers do.
To obtain drift statue the right way, it is necessary to have good car control using a two-way limited-slip-differential. For one we can kick the car out under deceleration and acceleration while also having full traction to get the car back in line. If installation is done correctly, not only can the Kaaz unit outlast the OEM unit, it will also give you the ability to control how much lock up you need for on track and off track use. To do the install we decided to let the experts at Kaaz take a crack at our project which gives them time to explain how the new LSD is not only stronger then the last, but also how it is designed to fit with the U.S. market.