balls to the wall vs hell-bent for leather

balls to the wall

adv
  • With maximum effort or commitment. 

  • Full throttle; (at) maximum speed. 

hell-bent for leather

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

  • Synonym of hell-bent (“(recklessly) determined”) 

  • Synonym of hell-for-leather (“very fast”) 

How often have the words balls to the wall and hell-bent for leather occurred in a corpus of books? (source: Google Ngram Viewer )