RB20DET Flywheel

In my quest to produce the most horsepower from my Turbo SOHC KA, I had to have a drivetrain that can handle the power and abuse that would come from it. So, starting with the basics, I opted to change the stock flywheel to one from an RB20DET. This flywheel has the same 6 bolt pattern as the stock OEM flywheel which allows it to bolt on to the KA crank without any modifications and can use any performance clutch I choose from the 350Z line!!! I was able to find a RB20 flywheel on ebay. It was a new performance billet steel lightweight flywheel which only weighs 11.4 pounds.

350Z Clutch

Z32 Transmission Conversion

With the problem of burning up clutches solved, I then turned my attention to breaking KA transmissions. The only real solution was to swap out the transmission to one from a Z32. The VG transmissions have been proven to be nearly indestructable and withstand up to 1000 rwhp. In order to do the conversion, I first purchased a Nissan KA24 to VG transmission adapter kit from Xcessive Manufacturing. This allows a direct bolt on conversion. Next I purchased a Z32 5 speed transmission. I found a low price one on ebay. When it arrived, I took it to aamco who took it apart and examine it. Luckly for me, it was in very great shape and only needed new gaskets and seals. Along with the transmission, I will use a Z32 scatter shield from Mazworx. I doubt the RB20 flywheel will blow up, but it never hurts to have insurance just incase, plus I thought it look cool. To allow the Z32 shifter to remain in the stock location of the orginal one, Xcessive Manufacturing also sells a Z32 shifter kit. Since the transmission I purchased did not come with its orginal shifter, a performance Z32 short shifter was used instead. I found a cheap one on ebay. And to finally top the whole thing off, I crowned the shifter with an orignial OEM leather Z32 knob. Xcessive Manufacturing Mazworx

S15 Helical LSD Conversion

A LSD (limited slip differential) maximizes the amount of engine power getting to the ground by partially locking the two rear drive wheels together so the tires do not spin independently. Most 240SX have an open differential...which means no LSD installed. Some upgrade to the Canadian Viscous (VLSD) differentials offered to Canadian model 240's. The Viscous uses thin plates stacked in a bath of thick silicone fluid. The plates have perforated holes. The resistance of shearing the silicone fluid produces limited slip. I decided to swap out to the S15 "Torsen" Helical which was offered only in Japan. The torque-sensing Helical is a gear driven LSD that uses the phenomenon of incompatible worm gears which keep the wheels turning at the same rate. The worm gear drives a roll, but the roll cannot drive the worm gear. Basiclly the gear driven Helical LSD will last longer than the Viscous LSD, which is why I opted this route.

S15 Final Drive Gear 48:13 Ratio Conversion

The stock final drive gear ratio is 4.083 which is based on the number of teeth, ring gear/drive pinion: 49/12. With the large increase in horsepower, I decided to switch to a taller gear. Luckly the S15 uses the final drive gear ratio I was looking for: 3.692 (48/13). This makes for a direct bolt on for the HLSD. This will help control the wheels from breaking loose off the line, and increase top MPH speed in every gear.

Optional R200 Differential Cover Upgrade

The optional R200 finned aluminum differential cover has a capacity of 3.8 pints verses the 2.75 pints the stock differential cover can hold. The drain plug is also located on the bottom instead of on the side as on the stock diff cover. Nissan Motorsports may not have them in stock anymore, but I see brand new castings on ebay from time to time. As you can see from the orange sticker, this cover was intended to hold more silicone fluid for the Viscous LSD. Although I will not be running a VLSD, this will still bolt onto the differential housing and hold more fluid to help keep the Helical LSD running cooler. The final crowning touch to a complete differential upgraded swap.

300M Axles

This is a set of 240SX rear axles that were sent in for a bar upgrade and the housings re-tempered. This upgrade includes rolled spline 300M bars capable of 750HP at the wheels. The stock axle bars are made 8620 and are carburized. The stock axles are strong in the slow progression of power, but are quite brittle in an instant shock of power like a drag launch would give them. The 300M bars first start of as 4340 chromemoly steel and then it’s put into a vacuum chamber where more molybdenum is added and other impurities are removed. This is the strongest material you can make an axle from. 300M is the name metal company’s use for this material; it is also referred to as 4340 modified. Then a special heat treated process is done to add 15% strength to the factory ends, this along with the higher durometer boots and synthetic grease makes this this the ultimate axle up grade. The Driveshaft Shop