"Putting pedal to the metal" is an idiomatic expression that describes the act of going at full speed, accelerating rapidly, or working hard towards a particular goal. It is often used in informal conversations and can be substituted with several synonyms that convey the same meaning. Some of the synonyms for "putting pedal to the metal" include "giving it all you've got, going all out, hitting the gas, full speed ahead, pulling out all the stops, and pushing the limit." These phrases can be used interchangeably in different contexts to effectively express a sense of urgency or determination in achieving one's objectives.