In the possession of the author are two small gas turbines made by Rover, type 2S/150. Those two-shaft engines are designed to run at constant speed. For the intended use as vehicle power plant and as laboratory test bed, a power control is to be developed. Little technical data are known about the fluid flow through the engines, such as the maximum mass flow and the maximum turbine inlet and outlet temperatures. During an overhaul of one of the engines, all relevant dimensions were recorded. Using the data collected as mentioned above, a one-dimensional flow calculation was performed. The results of this calculation are velocity triangles for the compressor, the gas generator turbine and the free power turbine. Using service guidelines from the manufacturer, the components of the fuel system were tested for their serviceability. For the purpose of controlling the fuel flow, a suitable needle valve was selected for the expected fuel mass flow and fitted into the low pressure return line. The minimum required fuel pressure to prevent the extinguishment of the flame was determined. The knowledge gained through the tests mentioned above was put into practice by fitting the developed power control unit to one engine. This gas turbine was then mounted into a car and subsequently road tested.