racer vs racing car

racer

noun
  • A vehicle or other device used for, or designed specifically for, racing. 

  • Someone who takes part in a race. 

  • Any of several genera of colubrid snakes. 

  • A video game involving racing of any kind. 

  • An animal known for its fast speed, or suitable for racing; applied especially to a number of North American snakes, certain kinds of lake trout, etc. 

  • A racehorse. 

racing car

noun
  • A race car. 

How often have the words racer and racing car occurred in a corpus of books? (source: Google Ngram Viewer )