To be offered the opportunity to restore a Porsche of this significance is a very special privilege, but one which also comes with an equally large responsibility to ensure that the work is carried out meticulously and as accurately as possible.

What distinguishes a Carrera RSR prototype and what must be considered in the restoration of such a car, comes from an understanding of the circumstances in which these cars were initially built for the 1973 World Championship and how they evolved. Having started the season in Group 4 spec, Porsche then moved the works cars mid-season into the Group 5 prototype class. Here the rules were different and the RSR prototypes could be more freely developed on a race by race basis, ultimately way beyond the original Group 4 homologation specification.

Following three months of intensive research and the study of factory records, race sheets, period photographs and visits to the Porsche Museum archives, we prepared a detailed proposal and plan to restore R6 to precisely the specification that the car was in when it won the Targa Florio in May 1973. By studying Norbert Singer’s detailed race set-up sheets, we were also able to restore the precise set-up used on R6 in the race, right down to individual gear ratios used, spring rates and even the type of brake pads fitted.

Within Group 5, Norbert Singer had began to experiment with the vehicle’s aerodynamics by fitting a full-width rear spoiler extension to R6 to make the car more stable at high speeds. The rear spoilers were made from aluminium and were riveted either side of the ducktail to the rear arches with braces (nicknamed ‘Mary Stuart collars’).

A month later R6 was being further developed for the Le Mans 24 hour race, now fitted with even wider 12” magnesium rear wheels with centre-lock titanium hubs from the 917 and rear arches enlarged correspondingly and now fitted with larger fibreglass moulded ‘Mary Stuart collars’. The steel front wings were replaced with lightweight fibreglass wings and the steel doors were also substituted for a fibreglass type seen previously on the earlier 911R also with Perspex windows.

A few weeks later Porsche was then testing a long-tail on R6 at the Austria Ring at Zeltweg. Soon afterwards the vertical fins on the long-tail were connected by a horizontal wing for Watkins Glen where R6 made its final race of the 1973 season, although not in Martini Racing livery, but loaned to Penske and re-liveried in their famous Sunoco livery.py