Blackline BMW 210 Diff (153 x 14.5 - 37mm Offset) Helical LSD E39 540 E60 E90 mfl

Blackline BMW 210 (153 x 14.5 crown wheel bolts - 37mm Offset) Helical LSD

Passar E31 840ci (2.93 final drive)

E38 740i

E39 530d auto; 540i manual & auto; Alpina B10 V8 4.6 automatic; Alpina B10 V8s 4.8 (3.1 final drive)

E46 330d automatic; Alpina B3 3.3 manual; Alpina B3 3.3 Switchtronic; Alpina B3s auto

E52 Alpina V8; E52 Z8

E60 545i manual & auto; 550i auto; 550i manual with 215k; Alpina B5, B5s

E61 530xd manual Touring

E63 635d; E63 645i SMG & auto; 650i manual, auto & SMG; Alpina B6s

E65 730d; 745i

E83 X3 3.0sd Rear

E86 Z4 M3.2 Coupe (OE ratio 3.62)

E90 330d auto (7527757 final drive); 335i auto (3.46 7566152 final drive); 335i manual production up to 01/07

E92 330d auto (7527757 final drive); E92 335i auto (7566152 final drive); E92 335i manual production up to 01/07; Alpina B3 Biturbo automatic

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 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.