With 800 tracks in 49 states, 30 million fans, and a billion dollars a year in revenue, dirt track racing is the biggest sport you've never heard of. In this energetic hour, CNN takes you inside this fullspeed world of "bad fast" cars to meet the stars, watch the races, and join the millions for whom dirt track racing is a way of life. Before NASCAR became the largest growing spectator sport in the nation, drivers raced on dirt and still do. In tracks across the country, competitors ranging from longtimers to weekend warriors, local mechanics to consummate pros race roaring racing machines engineered nearly from scratch before legions of committed fans