Beginning with the 1972 911 Carrera 2.7 RS, the RennSport name has come to symbolize all that Porsche has accomplished in Motorsports. The GT3 RS reignited the flame of the much-missed original RS, and it set a benchmark which all its competitors aspire to today. Even the cabin followed the austere all-black RennSport tradition. Few sports cars come anywhere near the GT3 RS's race car precision, and yet can be driven to work! This is perhaps the primary reason for the variant's popularity & success, and the car is truly a race car for the road (rather than the other way around).
The GT3, named after the Fédération Internationale de l'Automobile (FIA) GT3 European Championship it was designed to compete in, uses the famed Mezger-bred race-inspired engine that derives its heritage from the units used in the Porsche 962 and Porsche 911 GT1 race cars. It has won championship and endurance races, including the GT class of the American Le Mans Series seven times, first overall in the 24 Hours of Daytona, and first overall at the 24 Hours Nürburgring six times.
Although the model was already a decade old in the form of 996 and 997 Series 1 variants,* for 2010, the Series Two 911 GT3 RS showcased a new 3.8-liter "Mezger flat-six", bringing total power output up to 450*Bhp. Today Hans Mezger is a legendary Porsche figure. Nobody imagined that the flat 6 he designed in 1963 would evolve into a race-winning engine that collected no less than 16 Le Mans victories - a record that surely will never be broken. The GT3 RS is a brilliant union of the legendary Mezger power-plant and a bespoke Porsche Ag Motorsports chassis. Lets not forget the input of the utterly brilliant test driver and development engineer, Walter Rohrl. The GT3 RS's success is also due in no small part to his influence and feedback.
Here is an awesome video with the perfect spread of RS's;
May the Horse be with you....