DARLINGTON, S.C. (AP) — It's Next Gen vs. Old School when NASCAR's new racer takes on its oldest superspeedway at Darlington Raceway on Sunday. “It kept me up this week thinking about that,” said Ross Chastain, who has won twice this season. “The Cup car right now is just so volatile to drive, especially the first few laps of practice, and I don't expect Darlington to be easy.” It rarely is over 72 years of racing.