In 1973, the shock absorbing bumpers were added as well as the duck-tail and wale-tail.  The Carrera RS with an even more powerful engine.It was designed for racing and entered in the GT competition. 1636 were produced in total.  The Carrera RSR 3.0 was produced in '74 with 20 more horsepower.  The 911 Carrera was also produced.In 1975, the first Turbo was produced including a 3.0 liter turbocharged engine  Also notice the "black look"  The doorhandles, window frames, and wipers were all black.