BMW HLF022 188 Blackline helical diff

• Blackline BMW E24,E28,E30,E34,E36,xE36,Z1,Z3 Helical LSD for vehicles fitted with 188 differential.

  Suits:-

  • E24 633csi, 635csi
  • E28 518i
    
  • E28 525i, 535i
    
  • E28 528i Manual
    
  • E30 325i Manual
    
  • E30 325ix Manual Rear
    
  • E30 M3
    
  • E34 524td Manual
    
  • E34 525i Automatic, Australian specification
    
  • E34 525i Manual
    
  • E34 530i, 535i
    
  • E36 323i Auto
    
  • E36 325i Manual and auto
    
  • E36 328i Auto
    
  • E36 M3 3.0
    
  • E36 M3 Evo 3.2 with final drive 2227453
    
  • E36 M3 USA
    
  • xE36 NOT FOR final drive 1428373
    
  • Z1 ALL
    
  • Z3 M Coupe
    
  • Z3 M Roadster

Helical LSD Advantages:-

• Equal rotational speed to both wheels
• Torque distributed according to traction
• Minimal service requirements - no clutches
• Quick reaction compared to viscous LSDs
• Gentle and progressive engagement, low noise
• Easily controlled power take-off and drifting
• Gears and body manufactured from 8620 alloy steel
• Direct replacement into stock differential

The Blackline helical LSD's are torque biasing, that is they distribute torque between the wheels, loading more torque towards the wheel with the best traction thus improving performance and driveabitily. Especially in low grip situations.
The helical gearing manages the distribution of friction within the LSD. When torque is applied to the helical gear system it creates force that pushes the gear into the differential body, thus creating friction. Increases of torque, increases the thrust force directly proprotional to the amount of torque. This allows the Blackline LSD to cope with considerable traction imbalance even under heavy power conditions, as would be the case on exiting a powered up corner. But at low torque conditions the LSD can differentiate quietly and smoothly, thus making the differential very suitable for normal road driving. The Blackline LSD uses the popular parallel axis helical geared configuration optimised for even load distribution. They are designed with a torque bias of 5:1 this means that if  one wheel loses traction then the wheel with the most grip can receive five times as much torque as the wheel that is slipping. However, five times zero is still zero, so all these helical LSD's work best when both wheels are 'planted' and some traction is still available on the slipping wheel. In practice this is rarely a problem as there is always some 'drag' on the slipping wheel, however some drivers expertly use left foot braking to partially lock the spinning wheel.
Note - Helical LSD's work especially well when combined with modern anti-lock braking systems.