Who’s The Best Air-Cooled Rennsport? 1973 Porsche Carrera 2.7 RS Sport Vs 1974 Porsche Carrera 3.0 RS

Up ahead, Total 911 Editor, Lee, is having a very good day at work. How can I tell just from looking at the back of his head? Well, he’s behind the wheel of a genuine, first 500, M471 ‘Sport’ specification 2.7 RS, and no one can have a bad day when in the driver’s seat of such a legendary 911. It’s even finished in Grand Prix white with the blue side script and colour-coded Fuchs. With the sun glinting off the famous bürzel, it looks sublime. At this particular moment, I’d wager that I’m having an even better time though, and not just thanks to the glorious view of the original Rennsport shooting up the road ahead of me.

1973 Porsche 911 Carrera RS 2.7 Sport

You see, Lee may be at the helm of a 2.7 RS, but in a game of very expensive Top Trumps, I have one-upped him on this occasion by precisely 307cc. The 3.0 RS that I’m currently piloting through the Essex lanes was launched just a year after Lee’s car and yet, it is often forgotten in debates regarding RS royalty. However, from all objective perspectives, the 1974 Carrera RS is the better car. Maybe it is the 3.0-litre car’s incredible rarity that has turned it into a forgotten hero – just 109 cars were built (51 were full racing spec RSRs) – or maybe there is something more intangible that has elevated the 2.7 RS onto its pedestal among the Porsche gods. That’s what today’s family reunion is all about. Getting these two Rennsport legends on the same stretch of tarmac has not been easy; over the last half a century, Zuffenhausen has released nearly 900,000 Neunelfers into the wild, with 2.7 RS M471s and 3.0 RSs accounting for a mere 258 of these. If my maths is correct, the probability of getting these two together was one in 75 million! Those are some pretty long odds but, after nearly two years of searching, we finally did it.

1973 Porsche Carrera 2.7 RS Sport

And, bloody hell, is it worth it. Short of chasing down Jürgen Barth in a 964 RS, my pursuit of the 2.7 RS from the cockpit of its 3.0-litre successor is the surrealist experience I’ve enjoyed during my three years in this job. As if to make the whole thing even more incredible, I’m strapped into the lightweight Recaro bucket seat, shifting with my left hand in one of only six right-hand-drive 1974 RSs ever made. It’s not just the orientation of the steering wheel that makes this particular 3.0 RS so special either. Currently owned by ex-historic racing ace, Nigel Corner, chassis no. 099 was originally ordered by Lord Alexander Hesketh, head of the eponymous racing team that vaulted James Hunt to Formula One stardom in 1973. With just over 38,500 miles on the odometer, the various owners of this super-rare Rennsport have not been shy ensuring it has been exercised as Porsche intended. As you may know, right-handdrive examples of the 1974 Carrera RS are so elusive that they are often referred to by their six colours; peering beyond the three-spoke G-Series steering wheel, I’m still in disbelief at being allowed to stretch its legs for today’s test. While 500 examples of the 2.7 RS were required to homologate the 2.8 RSR for competition, the same was not needed for the next Rennsport. Finding a loophole in the regulations, Norbert Singer found that just 50 cars were required as the 3.0 RS (and the new RSR) could be classified as an “evolution” of the previous year’s model rather than an all-new design. You’d never guess it to look at the 1974 car though. As they would frequently go on to do, Singer and the Motorsport Department pushed the regulations to their very limits to develop something else: the 3.0 RS.

1973 Porsche Carrera 2.7 RS Sport’s Interior

Taking a regular 2.7 Carrera chassis off the production line (complete with impact bumper dampers), each 3.0 RS was put together in Weissach where it was clothed in an incredibly lightweight bodyshell. Like the first 500 2.7 RSs, the exterior of the 1974 Rennsport was sculpted from a thinner gauge steel (nominally 0.8mm thick compared to later 2.7 RSs’ 1.0mm panels) while the front and rear valances, bereft of the impact bumper bellows required on regular road-going Carreras, were moulded from glass fibre, as was the incredibly delicate bonnet skin.

Porsche Carrera 3.0 RS-4

1974 Porsche Carrera 3.0 RS

Even the rear quarter windows and back windscreen were thinner than normal to help reduce the 3.0 RS’s registered weight to a scant 900kg. It’s a barely believable figure, especially when you begin to truly study the 1974 car’s muscular stance. The 2.7 RS may have marked the genesis of the 911’s rear wing but that ducktail looks decidedly dainty next to the 3.0-litre RS’s whaletail wing. And that’s the smaller, TÜV-approved version that doesn’t extend beyond the rear bumper. A much longer unit – fitted as standard to the RSR – was supplied with every car, just in case you intended to take your RS racing. The motorsport influences didn’t end there. Rather than the standard pressed Turbo flares, the swollen front and rear arches were hand-finished steel items (easily identified by their asymmetric profile). The same size as those fitted to the 2.8 RSR and IROC-bound RSRs (the latter also built on the 2.7 Carrera platform during the winter of 1973/74) the Group 4 rules allowed the 3.0 RSR to use even wider arches.

These housed huge 10.5- and 14-inch magnesium centre-lock front and rear wheels respectively, while the road-going RS was fitted with 9- and 11-inch Fuchs. On the suspension front, the 1974 Carrera RS retained the tried and tested torsion bar setup but there were some detail changes. The torsion bars themselves were stiffened up, both anti-roll bars were now adjustable and the rear semi-trailing arms were shortened, a development made on the factory 2.8 RSRs and rolled out onto the very last 2.7 RSs. Both the RS and 3.0 RSR were fitted with a new brake system, too. Utilising the lessons learned on the 917 programme, the floating discs were both drilled and vented while the calipers featured vertical fins to aid cooling. Additional air was sent to the front stoppers through the circular vents in the front bumper, which also housed a new central opening for the 3.0-litre engine’s oil cooler.

Under the glass fibre decklid, the 911/77 flat six in the 3.0 RS was essentially a roadtuned version of the twin-plug motor in the 1974 RSR (itself a development of the 2.8-litre engine from the year before). Using a new, stronger aluminium crankcase and an improved head stud arrangement, each cylinder bore could be increased to 95mm yielding over 300hp in RSR spec, allowing Porsche to keep pace with its rivals. The RS featured a lower compression ratio than its motorsport counterpart, however that, along with less aggressive camshafts and a single-spark ignition system, produced a peak output of 230bhp at 6,200rpm. But how does this delectable list of Rennsport ingredients perform on the open road? Well, first let me refresh my memory behind the wheel of the 2.7 RS ‘Sport’… Compared to ‘Touring’ spec Carrera RSs, this M471 car immediately feels much more purposeful in the cockpit. Gone are the 911S door cards, replaced by the characteristic leather pull cord and simple plastic handle. The clock, a mainstay of the fifth pod on most classic 911 dashboards, is also conspicuous by its absence, replaced by a blanking panel.

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