Thanks for your response,
The area the fairgrounds is proposing we use is a rodeo arena that doesn't get much use. The dirt does not have any sand and does turn hard packed when its dry. We are going to go out and test an 1/8 scale to see if the dirt breaks up.
I was told by somebody that if we can't ad clay to the soil the track would be no good and people wouldn't want to race because it would eat tires and be hard on the cars. Not sure if this guy is just being to picky or what. In your experience is this true? Watering and track prep is no problem.