The 911 has been raced extensively by private and factory teams, in a variety of classes. It is among the most successful competition cars. In the mid-1970s, the naturally aspirated 911 Carrera RSR won world championship races including Targa Florio and the 24 Hours of Daytona. The 911-derived 935 turbo also won the 24 Hours of Le Mans in 1979. Porsche won the World Championship for Makes in 1976, 1977, 1978, and 1979 with 911-derived models.