Born into a working-class family, Zarnock worked 45 hours a week as an auto mechanic while attending John F. Kennedy High School in Utica, New York, where he graduated in 1976. As a teenager he raced Motocross; while still in high school he built and drove show cars and drag cars. Some of the drag cars were used by other people for illegal street races; Zarnock claims that at one such unsanctioned street race he was kidnapped for a time. This story made its way all the way out to Los Angeles where he was asked to write it as a screenplay for actor–producer Christopher Titus. Zarnock later rewrote the script for publication as a novel.