He built stuff like a 1957 Plymouth stuffed full of an Allison airplane engine that ran nearly 150 mph in a period of time before Funny Cars existed. One could argue that EJ had the first one. He refined that idea after the Allison backfired through its supercharger and the car essentially became an oven. Potter suffered burns on his hands and arms while trying to get the car to a halt. His solution to the fire problem was to buy a brand new Dodge Dart station wagon, put another Allison (hooked to a tug boat clutch and a 1-ton truck rearend) in that and enclose the entire engine in a steel coffin to prevent the fire from escaping and burning him again.
“I did have a whole season running the Plymouth, the Southern tracks really liked that car, although guys like Ronnie Sox hated it. To see a big old Plymouth running as fast as I did didn’t do much for those guys.” excerpted from a great write up at Bang Shift: http://www.bangshift.com/blog/The-BangShift-Interview-EJ-Potter-AKA-The-Michigan-Madman.html
bottom two photos from http://www.jalopyjournal.com/forum/showthread.php?t=428585&page=927 and the top two I've posted before