Related Clues:

• Supercharger
• Certain engine
• Option on some sporty cars
• Kind of engine
• Engine booster
• Sports car engine
• Engine charger
• Start for jet, fan or charge
• Engine type
• Feature of some muscle cars
• Jet or charger start
• Supercharged engine
• Powerful engine
• Extrapowerful
• Gearhead's upgrade