Automotive suppliers build components and subsystems for manufacturers. Some even have complete assembly lines and build complete cars. One of the largest is Magna, which does both. As the transition to electric cars accelerates, suppliers like Magna are focused on building the battery electric powertrain technology of the future.
Recently, Magna took a stock Tesla Model S, removed its battery, motors and inverters and substituted its own proprietary components. When it left the factory in Fremont, the Model S had two motors, one in front and one in the rear. Now it has three, one in front and two in the rear. That arrangement allows for what automotive engineers call “torque vectoring.” Reduced to its essence, torque vectoring means that each motor gets all the power it can use at any moment in time and no more.
When a car negotiates a curve, the outside rear wheel travels a longer distance than the inside wheel, which means it has to spin a little faster. That’s hard to do if there is only one motor driving both wheels but easy to do if each wheel is powered separately. The motors in the Magna system are each rated at 188 horsepower for a total of 564. That’s less than the 762 horsepower of a stock Tesla Model S P100D, but Magna isn’t really interested in drag strip competitions. Its focus is on vehicle dynamics when the road gets twisty.
Wayne Cunningham, writing for CNET RoadShow describes what the Magna E1 is like up close and personal. “Things get a much more interesting when we power around a turn, fast enough to let the wheels slide a bit. The big car remains surprisingly level due to its heavy battery pack mounted low in the chassis, but so would a standard Model S, as I experienced in a challenge against an Audi S7.
“The advantage of torque vectoring showed in how easily the driver got the car around this turn at speed. I could almost see how the car aligned itself, turning most strongly than just the steering would allow, defying inertial forces that would otherwise drag it right off the road.”
Magna has no production plans for the E1, which is intended to demonstrate to global manufacturers its ability to deliver what it calls its Highly Integrated eDrive system — a fully developed electric powertrain that is ready to go. Smaller companies like Mazda and Subaru, among others, may not have the resources to develop such system in house. Magna offers them the opportunity to get into the electric car game now rather than 5 years from now.
Source: CNET RoadShow
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