CONCORD, N.C. — NASCAR announced Monday that it will disqualify race-winning cars that break the rules this season, confronting its longtime culture of cheating with a stringent new penalty system.

“If you are illegal, you don’t win the race,” said Steve O’Donnell, NASCAR’s chief racing development officer. “We cannot allow inspection and penalties to continue to be a prolonged storyline. Race vehicles are expected to adhere to the rule book from the opening of the garage to the checkered flag.”

The new approach is a seismic shift for NASCAR because it traditionally wanted fans to leave the event knowing who won the race. If a car failed inspection, either at the track or in a more thorough secondary teardown at NASCAR’s Research and Development Center in the days following the race, driver and team were usually docked points, fined or suspended.

The penalties were typically not announced until several days after the race.