The term is actually soup up, supe up is incorrect. It comes from horse racing back in the 1920's, the slang for performance enhancing drugs given to your horse

The term is actually soup up, supe up is incorrect. It comes from horse racing back in the 1920's, the slang for performance enhancing drugs given to your horses was soup. https://www.merriam-webster.com/dictionary/soup%20up#word-history https://www.merriam-webster.com/dictionary/soup%20up#word-hi...