Actual Use for this....sorta (Score 2, Interesting)

Actually we used a turbojet made from a car turbo in my undergraduate mechanical engineering energy conversion lab.. Needless to say these thing get efficiency values around 10% to 12% or much less( I thin I remember a value 3% in my lab report). If I can recall my gas turbine design class, normal aircraft turbojets are closer to 60% or even 80%...