let it rip

idiom

variants or less commonly let 'er rip or let her rip

informal

: to act without restraint

It's the playoffs. If there was ever a time to let it rip, it's now.

—Matt Harmon

"It's definitely a confidence boost, so I wanted to go out and have a solid race to have some confidence moving forward," [rower Kara] Kohler told U.S. Rowing. "It's definitely good to let her rip out there."

—Jason Mastrodonato