Starting out in
midget car racing and
sprint car racing, Karl made his Champ Car debut in 1969 and qualified for his first Indy 500 in
1973 driving an
Eagle chassis powered by a twin-turbo
Chevrolet V8 engine fielded by legendary car owner
Smokey Yunick. He raced for another team in 1974, but returned to drive for Yunick in 1974 and finished 13th at Indy. In 1980, Karl entered the CART series and began modifying his own
McLaren chassis that he dubbed the McLaren-Karl. In the final race of the 1980 season at
Phoenix International Raceway, Karl and his chassis ran at the front of the field in second place until engine trouble dropped him back to 9th. In total, Karl raced in the 1969-1984 seasons, with 74 combined career starts, including the 1973–1975, 1978, and 1980-1981
Indianapolis 500. He finished in the top-ten eight times. His best finish was in seventh position in 1974 at the Ontario Motor Speedway in a 100-miler. ==Later years==