hell-bent for leather

adverb3

1. •
   determinedly recklessly, in a manner that lacks restraint.

   • [...] his Supply Officer was hell bent for leather to torpedo his tour as the Commanding Officer and wanted explanations, or at least reassurances. — 2003
2. •
   Synonym of hell-bent (“(recklessly) determined”).
3. •
   Synonym of hell-for-leather (“very fast”).

   • “Gosh!” said Marking. “Where the hell did the Japs get that? [...Was that] a Jap plane? God damn, it was fast.” And I agreed, “It was hell-bent for leather some place.” — 2009