Hi P.WRX,

We are able to supply Cusco LSDs which include the 1way, 1.5way and 2way. We do not keep these in stock in Australia but we stock them in our Japanese warehouse and it will take 1 week to fly them in from order.

These units will improve your understeer dramatically. The Cusco Type-MZ LSDs are the ones used in Tarzan's World Time Attack Subaru GD.


How the Cusco LSD works, as explained by Cusco Japan:

"An LSD system eliminates the uneven power distribution which tends to apply more rotational drivetrain
energy to the wheel that has less grip.
During aggressive driving (involving lots of turns), an LSD unit efficiently distributes the torque from the
wheel with less grip capabilities to the wheel that has more, enabling more traction for the vehicle.
(Basically, it eliminates the difference in rotation between the left and right wheel during a vehicle turn, with
even power distribution to each wheel).

There are many components inside the LSD casing, but the effectiveness of the unit (locking rate) depends
on how much pressure is applied as well as the contact surface area of the clutch plates.
The effectiveness (locking rate) can be altered by several ways. Changing the cam angle of the pressure ring
effectively works to change pressure and reaction time of locking, also changing the surface area of the
clutch plates by its size or quantity to manage how much pressure is applied.

CUSCO is the only manufacturer which provides a setting for all three options!
1. 1 - Way: The LSD is effective when load is applied to the differential (applied throttle load), and is not
effective when load is not applied.
2. 1.5 - Way: The LSD is effective when load is applied to the differential (applied throttle load), and is
half-effective when load is not applied.
3. 2 - Way: The LSD is effective both ways when there is load or no load applied to the differential.

Selecting between RS and MZ:

The initial torque of an LSD unit is ideally measured at its static pressure resistance. It is possible to measure
when the LSD unit is equipped on a vehicle, however added variables that contribute to more resistance
such as gears, bearings, and oil seals may vary to the final result. Another adding variable is the gear
oil, which increases resistance depending on its temperature.
There are a lot of benefits from low initial torque setting; low power loss, low chattering noise, improved
durability as clutch plates are lower pressured than type MZ ‘s initial torque, and higher efficiency with
smoother oil flow between plates.

The primary difference between RS, MZ, and Hybrid units is the applied initial torque amount and the
activation direction.
The MZ model LSD is designed where the activation pressure opposes the direction of the initial torque
with the utilization of a cone spring. The LSD operation first becomes engaged when the opposing pressures
start working against one another.

In the RS Model, the activation pressure is applied to the same direction of the initial torque with the utilization
of a coil spring. Therefore, the initial torque is set lower than the MZ model enables a smoother and
quicker initial clutch plates engagement from a non operational to a fully functioning state even despite a
low initial torque rating is set. The virtues of a low initial torque setting is that it enables a smooth turn even
while the LSD mechanism is not activated. Because of the coil spring design, it provides overall gentle and
stable operation."


The following is recommended and neither Cusco Japan, Evolution R and INGMAX Japan will be responsible for your choice as every driver has his unique driving-attack style.

AWD (circuit and time-attack) --

Oval Course:
F: 1 way R:1 way or 1.5 way

Track with multiple turns:
F: 1 way R:1.5 way or 2way

AWD (Rally) --

Minimal turns
F: 1 way R:1.5 way or 2 way

Multiple turns:
F: 1.5 way R:1.5 way or 2 way

RS LSD ----- P.WRX $1450
MZ LSD ----- P.WRX $1350

The Rear LSD below has already been sold to a P.WRX member.
Below is a pic of the Cusco rear 2-way RS LSD for the R180 diff: