Torque vectoring technology is defined as a vehicle’s ability to vary the power to each wheel - controlling the torque applied to the wheels independently of one another to provide more stability, more responsiveness and more agility in an instant.
A conventional differential distributes the driving power equally to each wheel. Whether the vehicle is rear- or front-wheel-drive, there is basically a 50/50 torque distribution, meaning that the wheel with the lowest traction dictates the overall traction of the vehicle.
GKN has been researching and producing electric drive transmissions and electric axle products in an array of guises, with examples of electric axles found on production Plug-in Hybrid Electric Vehicles (PHEVs) including Volvo, Porsche, BMW and Peugeot Citroën.
Xtrac’s new P1227 is big news in this area and was developed to address the growing demand for single-speed, lightweight EV transmissions. It can be integrated with motors from BorgWarner, GKN and YASA, all of which worked with Xtrac to integrate their technologies into the transmission.
The P1227’s dual electric motors provide inherent torque vectoring capabilities, and the system is designed for maximum flexibility. It can be used in front-wheel, rear-wheel or four-wheel drive configurations, with an open or a limited-slip differential, and can also be used with a single electric motor.
The technology is quite intriguing when you overlay it with the varying incarnations of Formula E powertrains and could provide valuable insight into heavier cars using dual-motor technology such as NEXTEV TCR and DS Virgin.
While Sam Bird has been able to drive around the balance issues of the rear-heavy, dual motor-configuration, team mate Jean-Eric Vergne and both NextEV drivers haven’t been silent on the systems short-comings.
However, with Formula E bound to make advancements over the next decade (with more and manufacturers entering the fray), we could see a number of configurations – should the FIA allow – such as four-wheel drive or even more wheels! Harking back to the crazy F1 innovations of the 1970’s.
In 2012, NISSAN GT-R LM NISMO design head Zach Eakin designed a bespoke 5-speed transaxle for the DeltaWing that weighed less than 33 kg’s. The unit could as an open differential, but the real trick was the way it could act as a torque-vectoring unit (run by a small electronic motor) which controlled the relative speed of the inside and outside wheel. A similar unit was banned in World Rally Championship 2006 because it was simply too efficient.
Although never publicly used on the TelaWing in competition, the torque-vectoring differential hoped to maximize tyre life and to fine- balance; look at steering angle, lateral acceleration, and the path of the car.
The GT-R LM NISMO used the stored energy that is released out via the rear wheels under initial acceleration to reduce “power on under steer” and tyre wear. As the speed builds, the ice power could slowly be blended in via the front wheels till it finaly took over, however torque vectoring front diff would still be very valuable in blending the power in and preserving the front tyres.
Whichever way the series goes, expect to see torque vectoring play a major factor.