Throughout its lifetime, the 911 has been modified by private teams and by the factory itself for racing, rallying and other forms of automotive competition. It is among the most successful competition cars ever. In the mid 1970s, normally aspirated 911 Carrera RSRs won major world championship sports car races such as Targa Florio, Daytona, Sebring and Nürburgring, even against prototypes. The 911-derived 935 turbo also won the coveted 24 Hours of Le Mans in 1979. (Wikipedia)
The Evolution of Porsche 911
The Porsche 911 (pronounced as Nine Eleven, German: Neunelfer) is a luxury 2-door sports coupe made by Porsche AG of Stuttgart, Germany. It has a distinctive design, rear engined and with independent rear suspension, an evolution of the swing axle on the Porsche 356. The engine was also air-cooled until the introduction of the Type 996 in 1998. Since its introduction in autumn 1963, it has undergone continuous development, though the basic concept has remained little changed.