E39 Rear Suspension

E39 Rear Suspension







The E39 rear suspension is essentially the same design as the "4-link integral rear suspension" introduced on the E38. Each wheel is supported through four links to the sub-frame. One of these links being the "integral" link that connects the lower and front upper arms. The "elasto-kinematic design features" of the suspension controls toe angle changes precisely to provide stable and responsive handling.

As with the front suspension, aluminum components are used on the rear suspension wherever possible. The aluminum components include:

- Sub-frame
- Outer strut tubes
- Spring pads All four control link arms

These aluminum components coupled with a smaller differential result in a weight reduction of 23 kg (50 lbs) over the E38 rear suspension.

Elasto-Kinematic Design

Elasto-kinematics relates to the suspension system design type. The term "elasto" implies stretching, which in fact the system does. Under extreme load (acceleration, turning, braking) the suspension changes its geometry to counteract inherent changes induced by the increased loads.

Example: Braking







The system changes are predetermined and built into the system. The geometry changes provided by this system correct for unwanted changes that occur under load in non- elasto-kinematic systems.

Sport Suspension
The 540i with standard transmission will be equipped with the "M-Technic" sports suspension. It provides firmer ride/handling characteristics through the following modifications:

- Firmer spring rates - 5% front/20% rear
- Firmer shock absorbers - 30% front/15% rear
- Larger anti-roll bars - 25mm front/15mm rear
- Lowered by - 20mm front/15mm rear

The front struts of the sport suspension system are identified by a black triangle on the strut label.