200 mph is the same as 321.8 km/h and 244.9 mph equals 394.1 km/h .
While the cars may reach speeds of about 200 mph ( 321.8 km/h ) on certain tracks , Russ Wicks drove a stock car built to NASCAR 's specifications 244.9 mph ( 394.1 km/h ) during a speed record attempt at the Bonneville Salt Flats in October 2007.Russwicks.com article on the speed recordNASCAR Cup Series engines carry a Freescale-provided electronic control unit , but traction control and anti-lock brakes are prohibited .
NASCAR Cup Series