KAAZ SuperQ Limited Slip Differential for Toyota GT86 - Subaru BRZ (1.5way)
A KAAZ LSD has several (8 to 24) internal clutch plates. The LSD is activated by pressuring the clutch plates which will produce a very strong locking performance and superior response during performance driving.
In general, a Clutch Type LSD has pressure rings and friction plates inside the differential case. The LSD acts as a standard differential when a car is moving straight or the rotational difference between left and right wheels are similar. Once there is a rotational difference among wheels, the cross axis, which is set in the middle, will press the pressure rings, then the pressure rings will transfer the movement to the clutch plates. When all the clutch plates are engaged, both wheels are locked and the torque is transferred equally to both wheels.
Types of KAAZ LSDs
KAAZ offers two types of limited slip differentials: 1.5-way and 2.0-way. The two different configurations reflect the design of the cam grooves, which in result allows the limited slip differential to perform differently under acceleration and deceleration. Depending on the type of racing desired and the level of skill, choosing the proper type could enhance and optimize performance.
1.5-way Differential
The 1.5-way differential is recommended for most types of motorsports driving. On acceleration, the 1.5-way optimizes the performance, which is followed by a lighter lockup during deceleration. This makes for the ultimate traction on road racing. Although some drifters use KAAZ’s 1.5-way limited slip differentials, KAAZ’s 2.0-way LSD offers much better performance for drifting applications.
2.0-way Differential
Since drifting requires a near analog (on or off) full locking of the differential, a high preload, high ramp response, max clutch pack arrangement will generally deliver the best results. With a 2.0-way KAAZ LSD, the engine braking (coming off throttle in gear) delivers a similar locked condition, making the car as predictable as possible during switchbacks and the like. Since a gear-type LSD never locks both wheels, a tremendous amount of heat will build up as it oscillates the power delivery to the rear wheels. KAAZ’s 2.0-way LSD is designed to maintain sideway-motion in the rear even during shifting, making it the much better option for drifting.
ON throttle: The blue arrows represent the force being applied to the clutch discs during throttle input. A 1.5- and 2.0-way LSD will all have the same behavior when throttle is applied, as long as the cam angle, preload and clutch arrangement is the same.
When throttle and torque input into the differential is light, the applied force on the clutch packs is light. Heavy throttle input increase the force and the amount of slip.
OFF throttle: This is where having a 1.5- or 2.0-way LSD makes a difference. When there is no throttle input and the vehicle is decelerating thanks to engine braking (not vehicle braking), a 2.0-LSD has the same cam angle for accel and decel and as a result it will deliver the same amount of slip limiting based on the torque input. A 1.5-way uses different cam angles to add less locking on decel than acceleration.
Clutch Materials
All KAAZ LSDs rely upon metal clutch discs. There are two different versions of steel clutch used by KAAZ: standard steel and WPC-treated steel. These clutch discs generally provide a very long clutch life. Most of these clutch discs are grooved to improve lubrication flow, but some will have both flat and smooth discs mixed in with the grooved.
Clutch Plate Treatments
KAAZ LSDs now feature WPC treatments as an option on their clutches. WPC is a proven process that has been utilized for many years in the racing and automotive industry. WPC is not a coating, it is a treatment that enhances the surface to reduce friction and strengthen the parts. WPC achieves this process by firing ultra-fine particles towards the surface of a product at very high speeds. The resulting thermal discharge permanently changes the surface, strengthening structure and creating a harder more durable final product.
The ultra-fine media of the WPC process, when projected at high velocity towards the product surface, creates compressive stress at the impact points. At the same time, a micro thermal reaction takes place. It effectively seals minor surface fractures. It also allows a condensed surface to form that has improved density due to compaction. This altered and highly compact surface condition overcomes the problem of brittleness, that is usually encountered when metals are hardened.