One of our customers ran 6.8 second quarter mile time in a match race funnycar at a racetrack that was 50′ above sea level (high air density).? Then he towed to a racetrack at 5,500 feet above sea level (low air density).? Using the math in the Fuel Injection Racing Secrets book and the 5000 Horsepower on Methanol book, his setup was computed for the high elevation track with low air density.? The setup from the computation was put into the racecar in preparaion for the high elevation event.? Then, off the trailer, he ran 6.8 seconds and was low qualifier for that match race event.
This illustrates the importance of tuning your car for it’s location. Higher altitudes have less oxygen in the atmosphere so the air-to-fuel ratio needs to be adjusted accordingly. Otherwise the same engine can perform extremely well or bad depending on the atmospheric conditions at the track.