Bang shifting (early) with brass synchronizers. 24 psi front tire pressure. Air temperature 64 degrees Fahrenheit. Intake air temperature 89 degrees Fahrenheit. Approximately 565 feet above sea level.
Quite a bit. Internals, valvetrain, bolt ons, electrical, port work... The answer is A LOT. You can't pull like this in a stock 420A. The car also has ~200 lbs weight reductions.
