I was delighted to see your profiles on the Porsche RS 3.0 and the RSR 2.8 in the April issue as I have been researching their histories for several years.
I happen to believe that these cars are the Seventies equivalent of the SWB Ferrari Berlinetta (RS 3.0) and the 250 GTO (RSRs). In my opinion, it is more accurate to describe the RS 3.0 as a civilised version of the RSR 2.8 than an uprated RS 2.7. One or two points, though, arose from the articles which need clarifying:
RSRs — both 2.8 and 3.0
It was not the twin-plug heads and four-bearing racing cams which were responsible for the increase in power of the RSR over the RS. This was primarily due to the uprated compression ratio, (10.3: 1) and the large competition Bosch fuel injection pump used together with enlarged ports and valves. Twin-plug heads only gave an extra 5 bhp. They were primarily employed to promote even more burning of the mixture.
Regarding the production numbers of the RS 3.0 and RSR: the factory, in a press release of November, 1974, gave the number of 109 cars for both the RS and RSR 3.0s. In fact they produced 48 RS 3.0s and went on to build extra RSR 3.0s due to demand. I have discovered 51 of these cars existing today though there may be one or two to surface.
A special series of 15 RSR 3.0s were built at the end of 1973 with RS 3.0 bodywork for the International Race of Champions’ series in America whilst four more of the chassis run became the 2.14 litre turbo-engined racing prototypes of 1974.
John Starkey, Meriden, Coventry