Brake Energy Regeneration for greater efficiency and dynamic performance.
Brake Energy Regeneration also serves on the new V8 power unit in the BMW M3 to enhance all-round drivetrain efficiency to an even higher level, concentrating the generation of electrical energy for the car's on-board network on the engine's overrun mode and application of the brakes.
This highly efficient energy management related to actual driving conditions is made possible by intelligent control of the alternator. The two advantages offered by Brake Energy Regeneration in practice are that, first, specific, on-demand generation of electrical energy serves to reduce fuel consumption, while, second, the driver benefits directly from the disconnection of the alternator when the engine is running under load: With the generation of electric power being cut off when running under load, more drive power is available to accelerate the car, meaning not only greater all-round economy, but also extra driving pleasure.
With the number of charge cycles increasing as a result of such intelligent power generation, BMW combines this Brake Energy Regeneration tech-nology with modern AGM (absorbant glass mat) batteries able to withstand a much greater load than conventional lead acid batteries. In an AGM battery, the acid is held in micro-glass-fibre mats between the individual layers of lead, the battery thus remaining able to store energy over a long period even when charged and discharged regularly.
Even greater performance: the new engine management system.
The MSS60 engine management system is the central "brain" responsible for the car's excellent performance and emission data. The system is an evolutionary development of the engine control unit already featured in BMW M GmbH's V10 drivetrain, raising the standard of control functions to an even higher level: While the control unit on the V10 engine, featuring more than 1,000 individual components, already offers a level of package density quite unparalleled by the competition, the number of components in the MSS60 control units is even higher.
Benefiting from this highly sophisticated concept, MSS60 coordinates all functions of the engine with the various other control units on the car. The three 32-bit processors are in a position to handle more than 200 million individual operations a second, taking, for example, more than 50 incoming signals to calculate the optimum ignition timing individually for each cylinder and operating cycle, the ideal cylinder charge, the injection volume and injection timing. At the same time, the MSS60 control unit calculates and sets the optimum camshaft angle, just as it sets the positions of the eight individual throttle butterflies.
Electronic throttle butterfly control measures loads and forces for optimum management, measuring the driver's commands by means of the potentio-meter on the gas pedal and converting this signal into the appropriate response. The Drive Power Manager then adjusts this signal by adding additional input from ancillary units such as the climate compressor or the alternator. Signals from the idle speed control, exhaust management and knock control are also coordinated and compared with the maximum and minimum force signals obtained from DSC Dynamic Stability Control and EDFC Engine Drag Force Control. The final signal obtained in this way is then sent to throttle butterfly management, taking the current ignition angle into account. ...next page >>