The all-new Opel Insignia Grand Sport, arriving in the market early this year, will be available with a torque vectoring all-wheel drive system. The new Opel Insignia uses a GKN Twinster all-wheel drive system with a rear drive module that uses a twin clutch system without differential. The two clutches distribute torque between the front and rear axle and between the two rear wheels.
Torque vectoring provides intelligent control of the vehicle dynamics by sending precise amounts of torque to individual wheels; by over-speeding the outside wheel in a corner, torque vectoring can induce a yaw-moment, helping steer the vehicle. Conventional torque vectoring systems use a set of planetary gears either side of the differential to achieve only very low levels of over-speeding. Other systems use braking to achieve a similar effect—but waste energy and slow the vehicle in the process.
The Insignia’s all-wheel drive system can apply torque to one or both of the rear wheels independently, enabling torque vectoring capability across the car’s full performance range. The system reacts to the driving environment and driver intention by automatically modulating the clutches when torque is required on one or both sides.
|The new Opel Insignia utilizes a GKN Twinster all-wheel drive system with a rear drive module that uses a twin clutch system without differential. Click to enlarge.|
When cornering, higher torque is sent to the outside rear wheel, inducing rotation around the vertical axis (yaw)—the Insignia turns in with more precision, responding more spontaneously to inputs from the driver.
Torque vectoring also contributes to safety by controlling the distribution of torque according to changes in throttle position, steering angle and road surface, thus damping the amount of yaw. This intelligent use of torque distribution—also known as “yaw damping”—results in neutral vehicle behaviour, making the car more stable and steerable for the driver.
New Insignia drivers can choose the amount of yaw damping to suit their driving style by selecting the appropriate driving mode: from high yaw damping in “Tour” to low in “Sport”, for sportier vehicle behavior.
Twinster can also make all-wheel drive more fuel-efficient. The clutches on the rear drive unit not only transfer torque; they also can disconnect it.
Twinster was first introduced and proven on the Range Rover Evoque. GKN is now also working on Twinster applications for vehicles with eDrive and rear-wheel drive.