Improve, slangily
Else clues• Add juice to, as an engine: 2 wds.
• Enliven
• Goose the auto engine
• Improve a muscle car engine
• Improve, as a motor
• Increase the power of, as an engine
• Make more awesome, as a car
• Make more powerful
• Slang, increase engine output (4,2)
• Turbocharge