key This can only be achieved through heavy turbocharging

key to ensuring good start-off performance. Realising very high efficiency also facilitates a comfortable transition between the hydraulic characteristic curve and the torque converter lock-up clutch within the power split. The power curve is defined using turbocharged engines which result in flat to slightly upward sloping curves. The torque converter lock-up clutch design is based on the three-channel system, which means there is a separate hydraulic channel to apply the clutch, as well as to other channels for providing the cooling oil. The path that the cooling oil takes to the clutch plate set is designed to flow directly towards the coupling package. This provides for especially effective and efficient cooling. Another feature is to separate the clutch disks by waved springs so that the clearance of the coupling package can be optimally used and drag torque is significantly reduced. The result is much improved performance, especially under cold-starting conditions, when engaging a gear typically reduces the rotating speed of the engine.Damper development is mainly influenced by three factors with respect to the torque converter, all of which target a reduction in CO2 emissions. First, the trend in engine design is toward increasing output and torque with ever-smaller engines (less displacement). This can only be achieved through heavy turbocharging or supercharging, which further increases rotational imbalance. This imbalance, in turn, is channelled directly into the drive line. Second, the good power delivery of engines at low speed, in conjunction with today’s typically wide transmission ratio, makes it possible to introduce an exceptionally low-speed drive program, whereby the engine is principally driven at higher excitation levels. Last but not least, developers want to eliminate slippage of the torque converter lock-up clutch in order to promote efficient power delivery, which would be impossible using the damping characteristics of this setup. The answer to these three challenges