Porsche’s decision to offer magneto rheological (MR) technology for the engine mounts of its seventh-generation 911 Turbo is part of a strategy to bring added smoothness and refinement to the powertrain, while contributing to enhanced cornering and traction capabilities.
The MR system was developed in collaboration with Delphi Chassis Systems, which was acquired in November by the independent BWI Group. Both Audi and Ferrari use Delphi-developed MR technology for dampers.
Explaining the Porsche application, BWI MR Mounts Manager Timothy Schlangen said: “With conventional mounts, there is always a conflict between tightly coupling the powertrain masses with the body to improve dynamics, or suspending it on softer mounts to improve refinement. With our MR technology, the mount can be tuned to control or isolate at appropriate frequencies in real time.”
The system uses magnetically “soft” (easily but temporarily magnetized) iron particles, suspended in a synthetic base fluid, held within a cavity in the rubber body of the mount. When a magnetic field is applied by a coil, the particles become aligned, increasing the shear stress and therefore the resistance to flow.
The stronger the magnetic field, the higher the dynamic rate (effectively the stiffness) of the system.
Schlangen stated that the new mounts bring three benefits to the Porsche 911—improved driving dynamics by increasing the coupling of the engine to the body when required, improved traction through closer control of vertical powertrain movements, and enhanced ride comfort by managing low-frequency powertrain motions.
“With real-time control, these objectives can be met with no reduction in the isolation of powertrain noise and vibration," Schlangen noted.