IC engine-turbocharger unit for a motor vehicle, in particular an industrial vehicle, with turbine power control

An engine-turbocharger unit (1) for a vehicle, in particular an industrial vehicle, having an internal combustion engine (2); a decompression brake device (6); and a turbocharger (3) in turn having a variable-geometry turbine (7) driven by the exhaust gas from the engine (2), and a compressor (8) driven by the turbine (7) and connected at the outlet to an intake manifold (4) of the engine (2); the unit (1) also has a throttling device (21) located on the outlet side of the turbine (7) and settable between a fully-open attitude and a closed attitude; the variable-geometry turbine (7) and the throttling device (21) are jointly controlled, thereby allowing independent control of the exhaust manifold pressure (Pi) of the combustion engine (2) and of the expansion ratio (Pi/Pu) of the turbine (7).