TURBOCHARGED INTERNAL COMBUSTION ENGINE BOOST PRESSURE CONTROL SYSTEM

A system for controlling the boost pressure in a turbocharged internal combustion engine comprising a control device (171), an operating device (11, 12, 13) controlled by the control device and operative in controlling the speed of a turbine (4) and means (22) for feeding to the control device (171) signals which represent the true boost pressure prevailing at a location upstream of the engine throttle valve (9). The control device includes a data processor (18, 21) in which there is stored data which relates to theoretic control-valve settings and values which are intended to give boost pressure control values as a function of engine speed. The control device is constructed to compare the true boost pressure with the given control value subsequent to an increase in load with a subsequent rise in pressure over an interval of time. The data processor (18, 21) is programmed, in accordance with the character of a change in the difference between the true value and the control value, to calculate this data control-setting correction data for regulating the control valve (13), and to write this data into a first memory (20, 21).