I actually built a ball valve with wipers cars DC motor and simple control circuit to turn it on and off as a safety shutoff valve for the fuel. I got myself a proximity speed pickup sensor and need to build rpm meter as well as interfacing it to the cygnal board. I will buy the proportional pressure valve suggested by Raghu and I will start the control manually at first to see how the beast behaves.
The problem is we need a highly pressurized air to start the turbine at 30,000 rpm then we inject the fuel to see how it goes which makes it even more dangerous in case the injected fuel was too much for the engine to start.
Thank you guys for the great tips and I will keep you informed how the experiment goes on.
Another catch, the guy who designed the beast doesn't know how to connect load on it, he is afraid of vibration if he done direct linkage.
Mahmood