hell-bent for leather vs quick as a flash

hell-bent for leather

adv

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

  • determinedly recklessly, in a manner that lacks restraint. 

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

quick as a flash

adv

  • Extremely quickly. 

adj

  • Extremely quick. 

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