I keep reading about DA. I understand that it is the lower the better, but what determines in. Temp, humidity, elevation? What is the formula for figuring it out? And, how does it efect performance and how do you compensate for it . If anyone could lead me in the right direction on this it would be appreciated. Thanks, rob

 

Density altitude is a theoretical altitude the air would be like on a standard day.

You can get the formula to calculate DA on my web site. http://www.hardtail.com/techtips/weather.html

Because DA is calculated from the elevation, temperature, humidity and air pressure, it's also possible to be below sea level. Mission BC is at 24 feet altitude. In the spring and fall when the air is cool, the DA is usually below sea level which makes for some record setting runs.

Then there are people like me who have to race at altitude. 3280 feet altitude but during the summer the DA has gone over 6000 feet.

The higher the DA, the less hp an engine will make. Especially on a N/A car.

 

Thanks, that was exactly what I was looking for! Definately more to it than I had thought though.

 

Bah. Try bandimere in the summer..........