A green flag cuts through the air, signaling rows of Sodi RX7 karts to throttle up their 200cc Honda GX engines and roar around the quarter-mile track. Inside the 40,000-square-foot facility that houses these karts, Chicago Race Factory's staff provides safety briefings and protective helmets to drivers, scheduling track time in advance or penciling walk-ins into the next available race. The track is also open to parties for birthdays, social gatherings, and corporate team-building events. Recognizing man's natural need for speed, they have formed competitive and league racing for true gearheads who want more laps around their racer-designed track, whose tire border prevents captive Michelin men from escaping back into the wild.