When Does Supercharger Kick In

http://louisdmss928.angelfire.com/index.blog/1636301/will-whipple-superchargers-perth-yella-terra-ever-rule-the-world/

Superchargers are a significantly uncommon type. While you can buy anything from a Peugeot to a Porsche with a turbocharger, only a handful of cars provide the instant-access smack of supercharged induction.