What every engineer should know about the torque vectoring system in the Ford Focus RS
For the latest generation of the Ford Focus RS, GKN Driveline developed a new version of its Twinster torque vectoring all-wheel drive (AWD) system. An innovative combination of new gearing ratios and control algorithms over-speed the rear wheels, helping Ford to create a car with unprecedented dynamics, feel and handling.
Why did Ford work with GKN? The company is the only one with the hardware, software and vehicle integration expertise for a project of this kind.
How it works
A GKN AWD system drives the Ford Focus with a Final Drive Unit (FDU) that uses a Twinster twin clutch system. The Twinster can apply torque to one or both rear wheels independently, enabling the vehicle’s dynamic torque vectoring functions across its entire speed range.
The version in the Focus RS uses new gearing ratios so that it delivers more torque to the rear wheels. When AWD is engaged, the rear wheels drive faster than the front, fundamentally changing the way the car feels and handles.
The vehicle turns into curves more sharply, responding more immediately to the driver’s inputs. In Ford’s “drift mode”, the AWD system delivers even more torque to the rear axle, delivering enough torque to the rear wheels for the Ford Focus RS to achieve a controlled “drift” through corners.
What it takes
To deliver torque vectoring systems of this calibre requires engineers who understand vehicle dynamics and have the ability to partner with an automaker on vehicle level attributes.
Ford awarded GKN the programme with just 18 months to go before launch. In that time GKN engineers designed and integrated both the Torque Vectoring FDU, as well as the Power Transfer Unit (PTU) and CV joint sideshafts into the base front wheel drive platform.
That takes teamwork. GKN’s in-house software and calibration teams and Ford’s vehicle dynamics engineers worked together on new control algorithms for the torque vectoring system to give the driveline four different driving modes.
GKN’s torque vectoring expertise helps create halo models that set new benchmarks for performance. By working with GKN on the standard AWD system and the torque vectoring version, automakers can realise the best possible result for their global platform.