Turbo Control System
The petrol engine is fitted with a wastegate turbo with an electric compressor bypass. The turbocharger is cooled with coolant from the engine's coolant circuit and from the engine oil. The turbocharger wastegate is controlled by a vacuum system with vacuum from the mechanical vacuum pump and control via the vacuum regulator. Such a system provides, as opposed to a pressure controlled system, the ability to control the wastegate valve regardless of the available boost pressure. This gives better accuracy, faster control and the ability to open the wastegate valve at the appropriate time, which previously could not be controlled. For example, the catalytic converter can achieve faster heating by opening the wastegate valve at idle. The exhaust gases can then pass via the turbine housing without being slowed down by the turbine. The exhaust gases then lose less in temperature and the power losses are reduced. Unregulated is when the wastegate valve closed. In the event of a fault in the vacuum system, ETA is used with assistance from the throttle to prevent the air flow and thereby avoid a dangerous engine speed.