To go gangbusters is to “perform well and vigorously” or “act with energy and speed,” as in an economy going gangbusters. The term recalls the swift aggression of 1930’s police forces decisively breaking up criminal gangs. The old-time radio show Gangbusters, known for its noisy opening sequence, complete with sirens and the rattle of tommy guns, helped popularize the term. This is part of a complete episode.