Dynamic Torque Vectoring Explained – Ford Focus RS
Behind all the glitz, tyre smoke and flashing lights of the recent Focus RS unveiling, there was actually precious little information about the upcoming hot hatch hero. Quotes of ‘well in excess of 320bhp’ are all very well but with no prices and no performance statistics it’s hard to judge how the RS stacks up against the competition.
Update: we now know the exact performance figures and price for the Focus RS. Follow this link to learn more.
However, Ford technicians are bullish about the Focus’ chances and much of that is down to the combination of all-wheel drive and a new Dynamic Torque Vectoring system. They must be very confident indeed as they’re happy that the RS can stand up to benchmark cars that include the Subaru WRX, Mitsubishi Evo, Mercedes A45 AMG and current class favourite, the Volkswagen Golf R.
Ford’s Dynamic Torque Vectoring system has been designed by British firm GKN Driveline and works differently to the systems we’ve seen in other road cars. In most rivals torque vectoring usually means tweaking the brakes on the inside front wheel to help pivot the car around the corner, but using the brakes means slowing the car. In Ford’s case the DTC system actually pushes more torque to the outside wheel, effectively speeding it up and pushing the car around from the rear.
The Focus RS can send up to 70 per cent of the power to the rear wheels, but the clever bit is on the rear axle where a pair of electronic clutches can then divert that torque and send up to 100% to either wheel. Ford says this effectively eliminates understeer into the corner but also allows the Focus RS to corner with over 1g of lateral acceleration.
To help explain the system, Ford kindly produced a fact sheet that goes into a little more detail. So here’s the science bit:
Ford Focus RS – Ford Performance All-Wheel-Drive
The innovative Ford Performance All-Wheel-Drive system with Dynamic Torque Vectoring introduces a new level of handling capability and driver enjoyment, combining outstanding traction and grip with unmatched agility and cornering speed.
The Ford Performance AWD system has been tuned to deliver exceptional grip – with lateral acceleration exceeding 1 g – and class-leading cornering speed and acceleration out of a bend. With neutral and adjustable limit handling, and the ability to achieve controlled oversteer drifts at the track, the system helps delivers the ultimate fun-to-drive experience.
Torque Vectoring AWD in Action
The ground-breaking Ford Performance AWD system features innovative technology to deliver outstanding driving dynamics:
- twin electronically-controlled clutch packs on each side of the rear drive unit (RDU) manage the front/rear torque split – and the side-to-side torque distribution on the rear axle
- independent RDU control unit continuously varies the front/rear and side-to-side torque distribution to suit the current driving situation
- intelligent system monitors multiple vehicle sensors 100 times per second
- a maximum of 70 per cent of the drive torque can be diverted to the rear axle; up to 100 per cent of the available torque at the rear axle can be sent to each rear wheel
- during cornering, the RDU pre-emptively diverts torque to the outer rear wheel immediately based on inputs such as steering wheel angle, lateral acceleration, yaw and speed
- to optimise handling and stability, the car’s brake-based Torque Vectoring Control is tuned to work in parallel with the torque vectoring AWD system
- AWD hardware is compact and weight-efficient to maximise vehicle performance
What Is Torque Vectoring?
Torque vectoring is the ability to vary the amount of torque being delivered to each side of a drive axle, so that one side receives a greater proportion of the available torque.
This effect – which can be achieved by special axle units or by brake-based systems – can achieve significant benefits for vehicle dynamics. During cornering, transmitting increased torque to the outer drive wheel helps to improve agility, stability and avoid understeer.