good morning

Today I am describing the new turbocharger adopted on the Fiat Tipo 1600 mjet with electric drive. It is a new Honeywell turbine model type GTD 1449VZ with variable geometry with Hella rod control unit.

The main feature is the lack of a piping circuit and solenoid valves to control the variable geometry.

We find an electric actuator with a control unit positioned on the turbine body. This system has an undoubted advantage in simplifying the system as the vacuum tubes and solenoid valve are eliminated. In the event of a failure, the Hella turbine and electric actuator assembly must be replaced. We assume that in the future it is likely that spare parts will be provided to carry out the overhaul.

How does the system work in practice?

The engine control unit receives the boost pressure signal via the turbocharger pressure sensor, processes it and then checks the actual position of the variable vanes via a position sensor. At this point, to increase the turbo pressure, it sends an actuation command to move the turbine blades by means of a PWM-modulated electrical signal to the control unit located on the turbo.

PWM control makes it possible to optimise the current consumption of the motor that moves the rod controlling the variable turbo geometry. compressor.

The system is under direct control of the engine management ecu, and in the event of faults, a specific error code can be detected.

Happy reading and warm greetings from Antonio and the Marelli team