Abstract: A process for the control of boost pressure of a turbocharger in an internal combustion engine as a function of the density of the ambient air. The internal combustion engine has an exhaust gas turbocharger with control means to control the boost pressure in which the actual boost pressure is determined at specific time intervals and compared with assigned values for the desired boost pressure taken from stored compressor characteristics. The boost pressure is adjusted as necessary. The internal combustion engine further comprises an engine control device having a control unit and a data storage unit.

Abstract: The invention relates to a process for control of limitation of the boost pressure of a turbocharger in an internal combustion engine as a function of the density of ambient air, the values determined for the actual ambient temperature T∞, for the actual ambient pressure p∞, for the air mass mL drawn in, and for the boost pressure pL being determined in this operating condition at assigned intervals and the actual pressure pVE at the compressor intake and the actual temperature TVE at the compressor intake being determined from these values by way of predetermined air mass dependent correction characteristics, the air mass throughput mLkor adjusted to the rated conditions of the compressor being determined at the compressor intake respectively from the temperature TVE determined at the compressor intake and from the air mass mL, the compressor speed dependent maximum permissible boost pressure pLmaxkor being taken respectively from the compressor characteristic for the maximum permissible turbocha