Thread: traction control?

is this done like LR?

by braking the "loose" wheel?





Quattro times two: Audi develops new sport differential

Posted Sep 6th 2007 5:03PM by Damon Lavrinc
Filed under: Tech, Audi


According to Motor Authority, Audi has developed a new differential that will find its way into all its Quattro-equipped vehicles next year. The new diff quells Audi's inherent understeer by shuffling torque between the rear wheels, thus improving overall road-holding and lending itself to more sporty (read: rear-wheel drive bias) driving dynamics.

The system, which sends 60-percent of torque to the rear wheels, will sense a loss of traction in less than 100 milliseconds and then send an appropriate amount of power to each individual wheel. Users will have the ability to select between three different preset modes, including "auto," "comfort" and "dynamic," the latter of which provides more competent handling at the expense of ride comfort.

[Source: Motor Authority]

Yep, this is common.

Traction control just works by braking the spinning wheel. You could argue that if you had both rears spinning (for example) by braking both rears the system had acted to seen 100% of the torque to the front in a landrover with an open centre diff.

These systems are very tricky though. In cars with stability control, they will do cool stuff like brake the inside wheels on cars understeering, and outside wheels on cars oversteering.

Obviously from this if there is power on at the time you actually effectively get a form of skid-steer system Note that this does not happen on cars with just traction control.

The only real difference between cars with traction control and stability control is the addition of lateral g sensors, steering wheel input sensors, and some electronics and calibration. The main physical components remain the same.