dcn@ihuxl.UUCP (Dave Newkirk) (04/27/84)
I'm glad somebody mentioned something really new in suspension design. I think even the BMW owners will agree that their suspensions are compromises, and that there are many cars that can corner better or ride better. Why not have both! The new Lotus design is called an active suspension. It uses an engine driven hydraulic compressor powering "synthetic springs" at each wheel, completely replacing spings and shocks. It is controlled by a computer with sensors on the hydraulic pistons and a pair of accelerometers for pitch and roll. When any wheel hits a bump, the computer raises the wheel and lowers it again before the driver can feel the bump. The program also does automatic load leveling. When you accelerate, the pitch change causes the front pistons to compress, reducing the lift. Under strong braking, the front would rise to prevent dive. Cornering forces are handled the same way, producing a flat-cornering car. The system is programmable: the prototype car has controls to change the handling from oversteer to neutral to understeer, and to change the ride height. It is also capable of reversing the normal handling behaviour - can you imagine your car rolling INTO the curve like a motorcycle, or raising the front when braking? The Lotus project is targeted toward Formula One cars, but it looks like it would be an excellent road car system as well. Data from Car magazine, November 1983, Dave Newkirk, ihnp4!ihuxl!dcn