Magna shows Tesla that three motors work better than two
Automotive equipment supplier Magna demonstrates a three-motor electric drive system, with torque vectoring, in a Tesla Model S.
Wayne CunninghamManaging Editor / Roadshow
Wayne Cunningham reviews cars and writes about automotive technology for CNET's Roadshow. Prior to the automotive beat, he covered spyware, Web building technologies, and computer hardware. He began covering technology and the Web in 1994 as an editor of The Net magazine.
"Don't call it a
," says Werner Ness, Product Manager for Magna Powertrain, as we walk towards the Magna E1 technology demonstrator vehicle in the parking lot. While the car clearly started life as a Model S, its Magna and E1 badges hint at something different.
Magna ripped out the Tesla drive motors and battery, replacing them with an electric drive system aimed at improved handling. Where the Model S came with two motors, driving the front and rear wheels, the E1 gets three, one for the front wheels, and two for the rear.
With a dedicated motor for each rear wheel, the E1 employs torque vectoring, overdriving the outer wheel to help the car negotiate turns.
Magna's test driver takes me for a short spin on the roads around the company's facility in Graz, Austria. He floors it from a stop, and I experience the car's incredibly quick acceleration. Is it quicker than the 2.3 seconds to 60 mph boasted by the Model S P100D? I'm not timing it, but it feels like it's in that general ballpark.
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 doesn't plan on mass-producing the E1. Rather, this car serves to show off what it calls the Highly Integrated eDrive System, which in this case uses 140 kilowatt motors integrated with single-reduction-gear transmissions and inverters. Magna's eDrive shows off a trend of traditional automotive suppliers offering electric drive systems as components, more easily integrated into vehicles than internal combustion engines. Bosch, a Magna competitor, is offering its own electric drive system, which it says can be implemented into a rolling chassis with just 12 to 18 months development time.
Electric drive components such as these could speed the development of new electric cars.
For Magna's E1, each motor produces 188 horsepower for a total of 564. That comes up short of the 762 horsepower from a Tesla Model S P100D, but Magna's Ness isn't really interested in drag strip competitions. Rather, the exercise shows the configurability of Magna's eDrive System.
Just one motor in this system would work for a typical passenger car, producing more power than the average four-cylinder internal combustion engine. Configurations with two, three and even four motors would be possible, with the car's computer regulating power to each motor, helping handling.
Magna will be showing the E1 and its Highly Integrated eDrive System at next week's
Frankfurt auto show