A turbo-charging system of an engine comprising: a central body on which a turbine and a compressor, both keyed on a same shaft, are mounted, and at least two flange diffusers connected to two Venturi tubes comprised in the central body and ending with nozzles. The turbocharging system is interposed between the engine air filter and the engine throttle unit, the turbine receiving from the nozzles the engine intaking air at the output of the air filter whose flow determines the handling of the turbine and, through the shaft, of the compressor.