If there ever was a technology that calls out for street use, it is a jet engine. There is a small subculture of jet hackers. Among them is New Zealander Bruce Simpson who runs a cool website of his experiments. He tells how he got started:
When I first started tinkering with pulsejet engine technology in 1999, I realized that there was huge potential for improving these devices. Although deceptively simple in construction, their design had changed little in the 55 years since the end of WW2, when they were rapidly replaced by the now common turbojet. The opportunity to apply 21st century materials and knowledge to the task of improving a design still mired in the 1950's was too great to resist -- so I set about developing a range of engines, each incremental better than the last.
In true enthusiast street use spirit Simpson tells you how to make one yourself. He sells a book on DVD with instructions.
"A step-by step video shows you how to build this pulsejet for around $20 using just regular hand-
tools. That's right, no welder or lathe is required."