Dover Xfinity results from September 30, Dover International Speedway hosts the NASCAR Xfinity Series on the 1 mile concrete oval in Dover, Delaware. Leaf springs are the oldest form of suspension in racing. Although they are the oldest, they seem to be the least understood. Leaf springs possess many desirable suspension features, such as dampening, forward bite, roll over steer, high anti-squat percentage, and high lateral stiffness. Torrentz will always love you. Farewell. © Torrentz.