The Torque on Demand system (TOD) designed by Borg Warner Automotive and transfers drive electronically while interacting with other systems such as Anti-lock Braking (ABS), Anti-lock Braking Differential (ABD) and Traction Control (TCS).
These systems are operated by a full Multiplex installation linked to the central processing unit that also controls engine management with fly-by-wire acceleration and throttle linkage. This combination of electronic management by inter-active and reactive computerised systems results in the most sophisticated drivetrain of any 4WD in this market segment.
The level of technical sophistication of Torque on Demand provides the benefits of all- wheel-drive coupled with the ability to provide two-wheel drive operation dependent on the needs of the driver or vehicle.
The principles of ABS are well known but Anti-lock Braking Differential (ABD) fitted to the Korando takes this sophisticated series of controls a considerable stage further.
With ABD the central electronic control body not only limits the locking of each wheel independently, it compares the braking efficiency of each wheel against another. In doing so ABD can then reapply brake pressure when required to maintain a constant velocity for each wheel and apportion brake effort to the front or rear of the vehicle as required.
One of the major advantages of the Borg Warner TOD system is the reduction of component weight when compared with a conventional less intelligent all-wheel-drive system as used by many competitive manufacturers. Noise, vibration and harshness is also significantly less in normal driving conditions through this reduction of components.
With the use of planetary gearset reduction and chain drive the incorporation of TOD reduces mechanical complexity but has superior compatibility with ABS and TCS. This results in significant reductions in wear rates for front axle components and the resultant lower maintenance and overall ownership costs.
The Torque on Demand (TOD) system provides power in normal driving situations only to the rear wheels. Once slippage is detected, power and torque is instantaneously transferred electronically to the front as required. This enhances off road traction, reduces on-road understeer and benefits handling agility and steering precision.
This ability of TOD to transfer torque while under the full control of an active traction control system (TCS) is a major safety factor, especially when drivers may not be totally skilled in the requirements of off road driving or the changing effects of adhesion levels when driving on dirt roads.
Torque on Demand removes the need for a centre differential and provides a rapid response in achieving all wheel drive through the electronic interface. The primary focus in TOD is the electro-magnetic clutch assembly that activates through a variety of inputs such as driveshaft speed; vehicle speed and throttle position to optimise the dynamic behaviour of the vehicle. Optimal throttle control is assured through the use of fly-by-wire technology.
The electronic microprocessor controlling the Torque on Demand system makes its commands and decisions without any input from the driver. It measures and applies the transfer of drive through to a wheel and eliminates the opportunity for wheel slip. The level of output torque required and the duration of torque application are directly related to the elimination of the wheel slip condition.