go hell-bent for leather

To move, act, or do something very quickly or as quickly as possible. When her ex-boyfriend walked into the party, Patty went hell-bent for leather to get out of there. The political candidates have been going hell-bent for leather trying to get last-minute support from voters ahead of Friday's election. Once we set off the building's security alarm, we went hell-bent for leather to get out before the cops showed up.