Blackline BMW E46, E81, E82, E87, E90 Helical LSD for vehicles fitted with small case 168L differential. Suitable for - E46 316i E46 316ti E46 318ci Manual E46 318i Manual E46 318ti Manual E46 320i Auto E46 320i Manual with 168K casing E81 118i Manual E82 120i Auto E87 116i Manual E87 118d Manual with 168L final drive E87 120d Manual with 168L final drive E87 120i Auto with 168L final drive E87 120i Manual with 168L final drive E90 320i Auto with 168L casing E90 320i Manual with 168L casing E90 320si Manual with 168L casing BMW chose after the mid 90s outside of the 'M' cars to not fit an LSD, instead limiting the power by traction control, thus limiting the performance potential. Combined with BMW's superb chassis and handling qualities this differential allows the power to be efficiently handled, making the car faster, especially in slippery conditions. 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 Blackline Helical LSD's - How They Work 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 driveability. 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 proportional 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. Note - Helical LSD's work especially well when combined with modern anti-lock braking systems. All LSD units are made to order allow 10-14 working days for production
