June 20, 2002
New variable damping system available on some 2003 GM models
Detroit, Michigan – Delphi Corporation, a major U.S. auto supplier, is providing its new MagneRide suspension technology to General Motors for use in some 2003 models including the 2002 Cadillac Seville STS and 50th anniversary edition of the Chevrolet Corvette. MagneRide is a high-performance, semi-active suspension control system that responds in real time to road and driving conditions based on input from sensors that monitor body and wheel motions.
The new MagneRide system is replacing Delphi’s Continuously Variable Real-Time Damping (CVRTD) system, which was previously standard equipment on the Cadillac Seville STS. General Motors calls MagneRide ‘Magnetic Ride Control’ and ‘Magnetic Selective Ride Control’ on the Corvette.
The new system uses Magneto-Rheological fluids and valve-less dampers to provide a wide range of damping force control. The MR fluid consists of soft iron particles suspended in a synthetic hydraulic fluid. When current is applied to an electromagnetic coil inside the damper’s piston, the resulting magnetic field aligns iron particles, changing the rheology of the fluid i.e., its resistance to flow, and thus produces a mechanically simple but very responsive and controllable damping action without any valves. An onboard controller continually adjusts the damping forces up to once every millisecond based on input from four suspension displacement sensors, a lateral accelerometer and a steering wheel angle sensor. On the Chevrolet Corvette, the driver can select between a tour mode that optimizes ride comfort and a sport mode that enhances driver feedback and handling performance.
“MagneRide builds on CVRTD and is viewed within the industry as a differentiating technology,” said R. Scott Bailey, director of engineering, Delphi Energy & Chassis Systems. “This translates into increased ride and handling performance for the end consumer. MagneRide brings these benefits to both luxury and performance vehicles, while at the same time eliminating certain compromises engineers must often make in designing suspensions,” said Bailey.
Delphi says consumer benefits include:
- Greater sense of safety and security due to improved wheel control;
- Minimized vehicle body motion for a flatter ride and more precise, responsive handling;
- Reduction of small road disturbances;
- Improved load transfer characteristics, providing better roll control and steering precision during sudden, high-speed maneouvers; and
- A quieter, more refined ride due to improved road isolation.