1973 Porsche 911 RS Carrera

When the FIA introduced a new displacement maximum of three liters for the World Championship of Makes, Porsche's successful 917 endurance prototypes were regulated out of existence. Porsche's competition department began work on a series of purpose-built race cars built atop the 911 for the FIA's Group 5 Special Grand Touring class. The result of their work was called the Carrera 3.0 RSR.

Porsche revived the Carrera name for its top-of-the-range 911 for the model year 1973. Shown at the Paris Auto Show in 1972, it was given the designation 'Carrera RS' for RennSport, and was designed as a limited edition product to compete in Group 4 GT racing. Homologation required that at least 500 be built; demand saw that figure surpass that figure, with production eventually reaching 1,590 units (including prototypes and homologation units) which allowed it to race in Group 3 for standard GT production cars. The first 500 examples were built to exacting homologation specifications and used a thinner gauge sheet metal and glass. Most of the 911 Carrera RS models were built to 'Lightweight' (M471 competition) specification, with the other examples delivered as the (M472) Carrera RS Touring, which included 911S-type interior fittings and trim.

The Carrera RS was based on a lightened 911S platform with a revised suspension, flared arches, and wider 7-inch rear wheels and tires (the front wheels remained six inches wide). The 2.7-liter, fuel-injected, air-cooled six-cylinder engine offered 210 horsepower and helped the model achieve a top speed of around 150 mph. The 2.4-liter 911 S's 70.4-millimeter pistons and cylinders were replaced with 90-millimeter aluminum barrels which were coated with Nikasil (Nickel-silicon carbide). It was given a Bosch mechanical fuel injection and an 8.5:1 compression ratio. The result of this work was the new Type 911/83 engine with a 2.7-liter displacement. The old Type 901 with its 'dog-leg' first gear was also replaced with a strong Type 915 five-speed manual transmission.

The Carrera RS Touring and its competition-oriented sister were built with extensive use of lightweight materials. The bumpers (Series 2 Touring models had steel rear bumpers) and engine covers were made from fiberglass. The 'ducktail' rear spoiler was added to the engine cover after wind-testing proved it was effective at increasing high-speed stability by reducing rear-end lift.

There were 200 M471 club-level competition racers built and they weighed about 100-200 kilograms less than the Touring model, with an overall weight of 900-975 kilograms. They had thinner-gauge steel for the roof panel, doors, and wings and thinner clear glass from the Belgian firm Glaverbel. Most of the Series 1 Lightweights received this special glass but only a few from the second series were available with this option. As would be expected, all non-essential materials were removed including sound insulation. The carpeting was thin and simple rubber mats remained. The clock, radio, glove box door, sun visors, and folding seatbacks were removed. The door latch handles and armrests were replaced with plastic pull handles and pull-cord door releases.

Touring models were often equipped with options such as leather upholstery, sunroof, and Blaupunkt radios.

The performance was sensational with 0-to-60 mph times under six seconds, 0-to-100 mph times under 13 seconds, and a top speed of 150 mph. It had impressive power, was responsive, forgiving at the limit, and was nimble. In a similar fashion to its Carrera RSR brethren, many of the Carrera 2.7 RSs were enjoyed for competition use.

by Daniel Vaughan | Sep 2019