Porsche began to use exhaust turbochargers to charge engines as of the early 70s. However, these attempts were initially applied only in racing. In 1972 Porsche developed a version of the 917 racing engine with exhaust turbocharger and 100 hp output for the American CanAm Series. Due to its success, Porsche won the CanAm Series in 1972 and 1973, Porsche used the experience with the turbo gained in racing for its serial sports car production immediately. In 1974 the first racing car made on the basis of the 911 was ready to use. It was a turbocharged version of the 911 Carrera 3.0 RSR.
