XShift Adjustable Clutch Type Front LSD 6MT

EXTERNALLY ADJUSTABLE PRELOAD

Unique among limited slip options for the Subaru, this XShift front LSD allows the preload to be adjusted externally using special tools (available separately).  Can be done in the car with the removal of the side carrier adjuster (sun dial).  Ideal for motorsport use allowing the limited slip characteristics to be adjusted for varying conditions.  Specify the required ramp angle set (ramps are also available separately): 45/20deg (1.5way Rally), 35/10 (1.5way Street/Circuit), 45/0 (1way track/drag).

The purpose of a differential is to allow independent rotation of wheels across the axle (front, rear, or center in an AWD application).  This is necessary due to the variation in rotational speed while cornering due to the different arc radii that each wheel travels.  An open differential allows free independent rotation of the two axles but will direct torque to the wheel with the least traction allowing for that wheel to lose traction early preventing early application of power at corner exit.  A gear type (Torsen or Helical) LSD uses a gear mesh arrangement to bias a percentage of torque from the low traction side to the high traction one.  However, when traction is very low or one wheel is off the ground little, or no torque can be transferred, and the unit works like an open diff.  A plate type LSD has a set of friction plates that are preloaded to some initial torque allowing at least some torque transfer even with zero traction or a wheel off the ground.  It also is capable of transferring high torque evenly and at an increasing rate according to the input torque from the engine This makes it by far the most effective limited slip option for motorsport especially with high power levels.  The downsides of a plate type LSD is greater influence on the handling balance of the car (usually negatively at corner entry and positively at corner exit) and noticeable noise and binding during tight cornering.  Additionally, this type of LSD requires frequent oil changes and eventual rebuilding to restore performance when clutch plate wear reaches an undesirable level.

What it fits:

• STI MY01-21 (TY856 MT)
• Legacy Spec B (TY856 MT)
• Forester STI (TY856 MT)