WORK OF ART PORSCHE 1973 CARRERA RS
The 1973 #Porsche-911-Carrera-RS
is recognised by many as being the finest #911
ever. Hailed by many as the greatest road-legal 911 of all time, the #1973 #Carrera-RS
remains top of the desirability stakes more than 40 years after its launch, but how many people are aware of the links between this desirable #Porsche-911
and the mighty 917? Words: Keith Seume. Photos: Stefan Bau.
Some people believe that the Carrera RS is the best road car that Porsche ever built, and it’s easy to see why they might think that way. But can you really say that this 42-year-old car is better than, for example, a modern #997
GT3RS, or the newly-announced #Cayman
GT4? That’s an impossible question to answer, for you have to put the RS in context with what else was around at the time.
Modern limited-run, high-performance Porsches, such as the 911 GT3 (and its sibling, the turbocharged GT2) are undoubtedly breathtaking cars: they are seeringly fast – too fast, one might argue for road use – and, in the case of the GT3RS, pretty uncompromising. They are brutal trackday machines that are, to be frank, a pain in the proverbial to drive on anything other than billiard-tablesmooth roads. Drive a GT3RS for very long on the average British country road and you’ll soon be visiting your dentist to have your fillings replaced…
And this is where we get to the crux of what makes the 1973 Carrera RS such a fantastic car. It is simply a great all-rounder. But before we go any further, let’s take a step back in time and look at the circumstances surrounding its development and release.
Elsewhere in this issue you can read of the story behind Porsche’s greatest race car of all time, the mighty 917 (The Big One). As the cost of developing and competing at the highest levels of sports car racing – Can-Am in particular – had spiralled to what many within Porsche believed was an unacceptable level, the company began to consider other more costeffective ways to promote its products.
Ernst Fuhrmann is well-known in classic circles today as the father of the four-cam motor in the 1950s. After a sabatical period at Goetze, he returned to #Porsche
initially as Technical Director, before being appointed Chairman of the Board in 1972. Fuhrmann’s return to Porsche coincided with the departure of Ferdinand Piech, father of the 917, who left to go to Audi. Fuhrmann made no secret of the fact that Piech’s obsession with the 917 and its race programme wasn’t in line with his ideas on how best to promote the marque. In Karl Ludvigsen’s Excellence was Expected, he is quoted as saying of the 917’s participation in Can-Am ‘That was a very interesting adventure, but one cannot constantly play on so many pianos. Now we are going to stay closer to production cars…’.
But Fuhrmann still believed in the value of racing as a way to improve sales, and even though he was personally at the forefront of the movement within Porsche to ultimately kill off the 911 in favour of the 928 (plans for which were already on the drawing board in the early 1970s), he knew the rear-engined, air-cooled model still had a few years left in it. ‘Racing is good advertising for every car,’ said Fuhrmann – even a flagship front-engined V8-powered GT, like the future #Porsche-928
Fuhrmann was a shrewd businessman as well as a great engineer. He looked dispassionately at the #Porsche-917
programme, weighing the expense incurred against the monetary returns in terms of sales – ie, did the 917 actually make the company any money? Amazingly, it seems it did, for the cost of the race programme was more than offset by the return in publicity generated by the 917’s successes on track.
Just two months after he was appointed chairman of the board, Fuhrmann gave the go-ahead to develop the 911 for racing. Not since the days of the #911R
had there been such a push, but this was not to be a short-term effort like the lightweight R. Porsche entered a raceready 911 in the #1972
GT Championship, beginning with the 1000km event at the Österreichring in June.
Driven by Björn Waldegaard and Gunter Steckkönig – an experimental race engineer with Porsche since 1953 – the highly-modified 911 was forced to run under the looser, but highly-competitive Group 5 classification. It finished 10th, behind a series of all-out competition cars. Now lay the challenge of how to apply the lessons learnt from this early success to the 911 as a whole.
The main questions were how to make the 911 more competitive on the track, and then to examine what modifications would have to be incorporated into a limited-series, road-going production car. To satisfy the requirements of the FIA Group 4 regulations, Porsche would need to build 500 examples – a far cry from the 25 (or, initially, 50) required years earlier for the 917 to be given the go-ahead.
Norbert Singer was placed in charge of the project and his first task was to see how he could ‘build in’ lightness, to achieve a target weight of just 900kg. This was done by reducing the thickness of the steel used on the body pressings of the earliest cars, from 1.00 or 1.25mm to just 0.7mm. At the same time, the glass used in all other 911s was replaced by thinner, lighter material made by the Belgian company, Glaverbel. Lightweight glassfibre panels replaced the steel deck lid and rear bumper/ overriders, too, on models destined for the track. Interior trim was an obvious candidate for attention, with the rear seats deleted, all sound-proofing removed and new door cards installed, which dispensed with the normal armrests and door pulls in favour of plain panels with lightweight plastic handles from a #Fiat-500
and a pull-cord door realease.
The heavy stock reclining seats were replaced, too, this time with lightweight buckets with thumbscrew adjusters to set the angle of the backrest. Oh, and there was no clock, no passenger sun visor, threshold trims or glove box lid. In short, anything that wasn’t needed got left in the parts bin…
The bodywork came in for some significant restyling, too, with wider rear wheel arches designed to accommodate 7Jx15 Fuchs wheels, the fronts remaining at 6Jx15. Tyres were 185/70x15 and 215/60x15 #Pirelli-CN36
radials. Under those wheel arches were #Bilstein
gas shock absorbers, which helped save just under 4 kilos, while a thicker front anti-roll bar (18mm instead of 15mm) was fitted, along with a 19mm rear.
Visually, the most significant change to the 911’s profile was the distinctive RS ‘ducktail’ on the rear lid. This followed extensive wind tunnel testing at Stuttgart in the early 1970s, which led to the incorporation of the small lip spoiler under the nose of the 911S models. That was fine for a car with the performance potential of the regular road-going ‘S’, but at higher speeds it was discovered that airflow over the rear of the 911 generated significant lift at speeds over 150mph. By adding this simple ducktail, according to Ludvigsen, lift was reduced from a heady 320lbs to just 93lbs at 152mph. At the same time, the Cd figure fell slightly from 0.41 to 0.40 – a small improvement admittedly, but still worthwhile in the quest for perfection.
A further advantage of the new spoiler was that it improved airflow into the engine bay, providing extra cooling and intake air for the new engine. And what an engine it turned out to be.
The contemporary production unit displaced 2341cc (optimistically tagged ‘2.4’ by Porsche), but by increasing the bore from 84mm to 90mm, the capacity rose to 2681cc (nominally 2.7 litres). This was a deliberate choice to allow the engine to be developed for use in the 3.0- litre class, and in fact meant the Carrera had the same bore and stroke as that of the 5.4-litre 917/10: 90mm x 70.4mm. As we are starting to see, the Carrera RS owed much to the mighty 917…
The lessons learnt from the all-conquering 917 didn’t stop there, for the Carrera’s engine featured Nikasil-lined aluminium cylinders produced by Mahle, in place of the Biral cylinders of the #Porsche-911E
models. This process proved to be far tougher than the previously-preferred chome-plating used on aluminium cylinders, thanks to the tiny grains of silicon-carbide contained in the coating. It also had the added benefit of allowing an oil film to adhere to the cylinder walls more effectively.
The new (or rather ‘revised’) engine, which shared the remainder of its major components with the 2.4-litre unit, produced 210bhp at 6300rpm and some 255Nm of torque at 5100rpm. The transmission – type 915 – was the same as that used in the mainstream models, other than a slightly taller fourth and fifth gear ratios than those used on the 911S.
The plan was to build just 500 examples of the Carrera RS (as the model became known) but as history has shown, the response was so great that this initial run sold more quickly than had been imagined possible. Four versions would be be available, the rarest being known as the RSH (for ‘homologation’) – a lightweight (960kg) model of which just 17 examples were built. Then came the #M471
options, better known as the ‘Lightweight’ and ‘Touring’ respectively.
The former was essentially a productionised version of the RSH, with slightly less attention paid to all-out weight savings. As a result, the factory-specified weight of the M471 model was 975kg, just 15kg more than the RSH. The #M472
, though, featured the same interior trim and detailing as the regular 911S, other than a smaller 380mm-diameter steering wheel. This trim package added around another 100kg to the all-up weight. The final offering was the 2.8-litre RSR (option M491), of which 55 examples were built for competition use. Ultimately, 1580 Carrera RSs were sold, not including the RSR – a far cry from the original planned run of just 500. However, by building 1000 (or more) examples, Porsche could now homologate the RS for use in the very competitive Group 3 GT racing category.
The value of genuine, original RSs has, over the last few years, gone through the roof. After a period in the late 1980s when even a Lightweight could be purchased for £20-25,000 in the UK, they have continued to rise in value at an almost alarming rate. This has led to tales of fakes and forgeries (which is where the latest forensic examinations of VIN numbers comes in useful – see Drive-My News, so it is a wise man who seeks expert advice before entering into the purchase (or sale) of an RS today.
But is an RS really worth a high-six figure (or more) price tag? How much better a car is it than a good 2.4 911S? That depends on who you ask. With a good ‘S’ costing between a quarter and a third of an equivalent RS, you’d need to be pretty set on Carrera RS ownership. But, on the other hand, there is no doubt that an RS is something very special – it’s a limited run model which has direct links to the 917. It was developed by Porsche’s finest engineers for use in the most competitive of all race categories. The letters ‘RS’ stood for RennSport, and that’s a pretty good indication this is something special. If you’ve not driven a 1973 Carrera RS, it’s hard to appreciate what a perfectly balanced package it is, be it in Lightweight or Touring trim – it’s definitely far more than just a ‘hopped up’ 911S. It hasn’t become the stuff of legends without cause. But what would you expect from a 911 born at a time when Porsches ruled the racetrack?