In a go kart, you're much closer to the source of horsepower than when you're riding in a car. All that invisible force leaps to life when you hit the accelerator, gently pushing you back into the seat. Drivers at Lehigh Valley Grand Prix feel that pull as they whip around a quarter-mile racetrack in gas-powered Sodi GT5 Proline karts. They slip past one another while making 11 brake-stomping turns, all with a vantage point not afforded by watching races on TV.

The karts feature air-intake units that trap their exhaust and keep the atmosphere fresh, and the track—constructed from 1,300 used Goodyear tires and the shredded remains of Mario Andretti's learner's permit—is outfitted with three observation platforms for track marshals to regulate each lap and guarantee riders' safety. Three-point safety belts, roll bars, helmets, and neck braces also protect racers during their white-knuckle trips around the track. A full-time mechanic keeps finish lines crowded by calibrating karts to run within three-tenths of a second of one another and hanging hundreds of piñatas from the checkered flag. At the facility's bar, Octane, racers can refuel with drinks and food while watching stock-car races on the five 42-inch TVs.