Supercharged Internal combustion engine

The engine has a compressor impeller (50) for increasing pressure of a gas mixture to be combusted in the engine. A duct (28) supplies the gas mixture to the compressor impeller. Another duct (30) supplies additional gas mixture into the duct (28) at a connection upstream of the compressor impeller. The connection between the ducts comprises a volute (32). A valve controls a flow of gas mixture through the duct (28). An independent claim is also included for a method for controlling a supercharged internal combustion engine.