With its CVO (Controlled Valve Operation) system solution for direct injection engines, Bosch has adopted a mechatronic approach that can make a valuable contribution to legal limits for emissions. Unlike conventional open-loop controlled injection, the control unit and high-pressure injectors constitute a closed loop in this setup. The control unit detects the triggering signal for the high-pressure injectors across the entire injection process and determines the timing for opening and closing the valve needles. Thus, the control unit can calculate the actual injection quantities of each injector and make adjustments where necessary. CVO offers an innovative and cost-effective approach to engine optimization.
With conventional wastegated turbochargers or fixed geometry turbochargers (FGT), a turbine flow area cannot be adjusted during operation.
Knocking is abnormal combustion in which the air-fuel mixture ignites prematurely due to exposure to high temperature and pressure, creating an unwanted high-frequency noise. When the compression ratio is increased, the temperature at compression top dead center (TDC) also rises, increasing the probability of knocking.