Car Culture: Getting a firmer grip on handling
Race tracks are usually all about speed, but not this time. I am at Mazda Raceway Laguna Seca, one of America’s most famous and challenging road courses, and my instructor asks me to drive at just 5 miles per hour.
It sounds frustrating but there is a good reason for the exercise. Mazda wants to demonstrate its latest vehicle dynamics technology, and the best way to do that is to start slowly.
Mazda’s new system, dubbed G Vectoring Control, is designed to make its vehicles steer and handle better and more safely, especially in inclement conditions. And the technology is intended to reduce stress on drivers, whether they are experts or not.
In the sunny California weather during our demonstration, the effect of GVC is subtle, even when driving over a wet part of the course. But Mazda’s own testing in snow and icy conditions reveals much more noticeable beneficial effects from G vectoring, especially in controlling slides and skids.
When it comes to handling, many of the world’s automakers are promoting “torque vectoring,” an approach that controls the power being delivered to individual wheels by applying the brakes. For example, when rounding a turn the inside front wheel is braked momentarily, which effectively sends more power to the outside wheel and therefore helps cornering traction.
However Mazda, which is making a name for itself among consumers for its driver-focused handling characteristics, is taking a different approach with its system. And as with all the best engineering solutions, its secret is its relative simplicity.
Instead of wasting energy by applying the brakes, Mazda’s system knows when the car is turning (thanks to steering wheel sensors) and fractionally reduces engine power at that point. This shifts the car’s center of gravity forward, putting more weight on the front tires, increasing their grip and thus improving the cornering characteristics.
Mazda development engineer Dave Coleman explains that one of the most important elements of a car’s handling is when the driver turns in to a corner. “If the car does not respond correctly, it unnerves the driver and leads to a whole chain of errors,” says Coleman.
At the racetrack, our 5 mph cornering and braking exercise is all about learning to sense the subtleties of steering and brake responses and how a car’s body leans and rolls.
With my senses finely tuned, I graduate to driving a Mazda6 at 20 mph around a larger oval parking lot course. The prototype car’s GVC system can be switched on and off so as to experience the difference. It’s hard to pinpoint exactly why the system feels superior, but video playback makes it clear that fewer steering corrections are needed. And it feels easier to tightly follow the curve of the corner.
Beyond the handling advantage, the GVC system is claimed to make journeys less tiring and stressful for drivers and passengers alike.
The idea, says Coleman, is to reduce the jolting and jarring motions occupants experience as a car’s weight shifts when braking, accelerating and cornering. In engineering speak, this is known — appropriately enough — as “minimum jerk trajectory.” The point is to smooth out as much as possible the awkward sensations that humans find discomforting, even on a sub-conscious level.
Mazda plans to roll out its GVC system progressively across its model range starting with the 2017 Mazda3 and Mazda6 sedans.
So for consumers looking to get the “jerk” out of their car, Mazda may have found an answer.
John McCormick is a columnist for Autos Consumer and can be reached at jmccor@aol.com.