Porsche 911 Carrera RSR ‘R7’: the full works

By Simon Hucknall

| 23 Nov 2023

Classic & Sports Car – Porsche 911 Carrera RSR ‘R7’: the full works

As far as feats of derring-do go, this one pales to nothing in the context of Porsche 911 RSR R7’s life-story.

But, given that I’m driving it as fast as I can behind a camera car in biblical conditions, on a hillclimb track not noted for its forgiveness, without windscreen wipers, it’s worth documenting.

More so because said car is, by common agreement, one of the most important competition Porsches surviving today – one that, 50 years ago, finished fourth overall at Le Mans.

The Porsche team Carrera RSR 3.0 ‘R7’ was a 1973 Le Mans phenomenon

Factor in its estimated value – £5m-plus is hinted at far too many times for comfort – and that liberal smearing of Rain-X across its windscreen does nothing to improve my sense of well-being.

The precariousness of this drive will haunt me for years to come.

But it’s more than worth it.

This intimidating, captivating, ex-works Martini-Porsche 911 Carrera RSR is known as ‘R7’, and was one of eight special R-numbered RSRs built by Porsche, only four of which wore its famous Martini Racing livery.

Greasy Tarmac and fat wheelarches make for an anxious Goodwood hillclimb in this rare Porsche 911 racing car

Three survive, and R7 is widely acknowledged to be the best-preserved and most original example, as well as the one that achieved arguably the most significant finish at the 1973 24 Hours of Le Mans.

That it was beaten only by three thinly disguised Formula One cars just adds to its mystique; for the RSR was no silhouette racer, but a car that could legitimately claim to share its roots with the by then decade-old 911 road car.

Back in 1972, according to Porsche’s newly installed chairman, Dr Ernst Fuhrmann, that had been the point.

Fuhrmann decreed that, while the 917 competition programme had been an unbridled success, its cost had been eye-wateringly high, even by Stuttgart’s standards, and risked becoming too detached from the core business of promoting its road cars.

The Porsche 911 Carrera RSR’s stripped cabin features a slender rollcage and the original steering wheel

Since 1970, the go-to race category for production-based GT cars was Group 4, but in order to be competitive, Porsche needed to field a more potent 911 contender in the 2500-3000cc class, which came in the form of the now fabled Carrera RS.

Launched at the Paris motor show in October 1972, the RS (for RennSport, or ‘Racing Sport’) needed to have a production run of at least 500 units to gain race homologation, which it achieved by April the following year.

The cooking 911’s 2.4-litre flat-six engine was enlarged to 2687cc for 210bhp, while the chassis and aerodynamics also received a raft of upgrades over the stock 911, creating a tantalisingly competent and lighter-weight platform for competition.

The familiar Porsche 911 dashboard reveals R7’s distant ties to the Carrera RS road car

While the RS is rightly revered, back then it was merely a stepping stone for Porsche’s racing ambitions, which materialised in the legendary RSR.

Just 55 out of a total run of 1580 RS models produced were given the magic M491 conversion code that transformed them into the competition-focused models.

The process started with a standard steel bodyshell off the regular 911 production line, prior to any rustproofing or noise insulation being applied.

As with the RS, a lightweight floorpan was fitted and suspension mounts reinforced (the extra welded plates are still visible on ‘our’ car today).

This ex-works Porsche 911 Carrera RSR wore the famous Martini livery at Le Mans

The 911’s basic chassis architecture remained: torsion bars and telescopic Bilstein dampers, with struts at the front and semi-trailing arms to the rear.

Few components escaped modification: the struts’ top mounts were given extra adjustability, and the standard torsion bars were complemented by adjustable anti-roll bars and a quicker steering rack.

But the biggest change came in the form of a new braking system based on that of the 917 racer, comprising cross-drilled, ventilated discs and finned, four-piston calipers, with full brake-balance adjustment.

Two fuel tank cut-outs on this classic Porsche 911 racing car: one takes fuel, the other is to release pressure during refills

Concealing them were, even by today’s standards, insanely wide Fuchs alloy wheels of 9in and 11in width front and rear (up from 6in and 7in respectively for the RS).

Taking it to another level, though, the RSR R7 we have here today sports gargantuan 11in- and 14in-wide, centre-locking 917 rims, fitted as part of a works package.

It’s those Carlos Fandango-style wheels that necessitated the RSR’s super-wide arches (the preservation of which are foremost in my mind each time I’m forced near to Goodwood’s flint wall by the camera car).

‘Full-bore assaults on straighter sections demand a weather eye on the tachometer, such is the engine’s free-revving nature and surprising smoothness’

To reduce weight – and especially to counter the added heft of those chassis reinforcements – thinner steel was used for the front and rear wings, with the works cars’ engine covers, bonnets and single-piece front bumpers all in glassfibre.

So, too, in R5, R6 and R7’s case, were their full-width ‘Mary Stuart’ rear spoilers (named after the collar ruff worn by Mary Queen of Scots), which gave these particular cars their nickname.

Along with the fitment of thinner Glaverbel glass, total weight was brought down to 839kg, some 80kg less than an RS 2.7 Lightweight.

No windscreen wipers for this classic Porsche 911 Carrera RSR, but metal clips keep the ’screen in place

The RSR’s mighty new drivetrain was then left to seal the deal, needing to be powerful enough for 180mph blasts down the Mulsanne Straight, but also durable enough to take on more potent but less robust rivals in the Sports Car classes.

For the 1973 season, Porsche used three different engines, each of which was derived from the RS’ dry-sumped, air-cooled, all-alloy, flat-six unit.

The first – the Type 911/72, mainly for privateer cars – displaced 2806cc, thanks to an increase in bore of 2mm made possible by cylinder heads that were further apart and Nikasil cylinder linings with aluminium rather than magnesium castings.

Forged pistons also facilitated a compression ratio increase from 8.5:1 to 10.3:1.

The Porsche 911 Carrera RSR’s extended rear wing provides a welcome increase in downforce

Twin-spark cylinder heads, four-bearing camshafts, enlarged valves and ports, revised Bosch mechanical fuel injection and titanium connecting rods completed what was by then a thoroughly circuit-focused package, producing 308bhp at a heady 8000rpm and 217lb ft of torque at 6200rpm – quite a departure from the 210bhp and 188lb ft of the RS.

But there was more to come for the works cars…

By April 1973, the Type 911/74 motor, with its Silumin-alloy crankcase, brought an increase in capacity to 2993cc and power to 315bhp.

Recognisable headlights on the wild Porsche 911 Carrera RSR

For Le Mans, the factory cars – including R7 – were fitted with an even more highly tuned Type 911/75 producing 330bhp.

So it must have been blessed relief to privateer teams running lesser RSRs that Porsche decided to compete in the Prototype class with its works cars, avoiding direct competition with the Production class.

Either way, RSRs were yielding impressive results across the board.

Apart from a toe-in-the-water outing for the first of the eight works RSRs – R1 and R2 – at the 1972 Tour de Corse rally, the RSR didn’t make its official debut until the first round of the 1973 World Sportscar Championship at the 24 Hours of Daytona in February.

The RSR’s beefed-up bodywork boasts dramatic wider wheelarches

Two cars were entered – R3 and R4 – and, thanks to some good fortune, drivers Peter Gregg and Hurley Haywood took R4 to victory, finishing 22 laps ahead of the second-placed Ferrari 365GTB/4C.

Works and privateer RSRs continued to be campaigned throughout the season, with consistently high-ranking results.

The first Martini-liveried cars had taken a competitive bow at the 6 Hours of Vallelunga race earlier in the year, securing a 1-2 victory, followed by second and fourth for the works cars at the following round’s Le Mans 4 Hours.

The Porsche 911 Carrera RSR’s high-compression Type 911/75 flat-six engine makes 330bhp

The first official outing for Porsche’s 3-litre RSRs (R6 and R8), running in Group 5 at the Monza 1000km, resulted in an inauspicious DNF for both cars.

But, for round six – the last running of the Targa Florio as a WSC event – the Swiss/Dutch driver pairing of Herbert Müller and Gijs van Lennep clinched victory in R6, though R8 was written off during the race.

At this point, R7 entered the fray for round seven of the championship, at the Nürburgring 1000km.

A brand new car, R7 was equipped to Group 5 specification and fitted with titanium hubs and the aforementioned 11in front, 14in rear centre-lock wheels.

‘The RSR’s mighty new drivetrain needed to be powerful enough for 180mph blasts down the Mulsanne Straight, but also durable’

For this and other RSR works racers, versus privateer cars, there was a serious package of go-faster goodies, such as Delrin suspension bearings, a bespoke transmission, shorter and stiffer rear trailing arms, coil-over dampers with titanium springs and a double-skinned rear crossmember welded to the firewall.

Driven by Müller and van Lennep, fresh from their success on the Targa, R7 qualified 15th and ultimately crossed the Nordschleife finish line in seventh place.

For the next and biggest race of the season, the Le Mans 24 hours, R7 was to achieve its most notable result, gifting it a provenance that lasts in significance to this day.

R7 is signed by one of its former pilots, Gijs van Lennep

Driven once again by the Müller/van Lennep pairing, R7 joined works cars R2 and R6, plus two 2.8-litre privateer RSRs running in Group 4.

Having qualified 18th on the grid, after three hours R7 was running seventh and going like a train, gaining two further places by mid-distance.

By 9am, it was fourth overall and held station until the chequered flag, seven hours later.

Incredibly, the only cars to beat it were developed from F1 machines, weighing around 250kg less than the Porsche: two Matra-Simca MS670Bs (first and third) and a Ferrari 312 PB, in second.

The Porsche 911 Carrera RSR traded the road car’s metal bonnet for a glassfibre item

R7 raced only once more in Martini colours, at the Zeltweg 1000km, before heading to the USA for the 6 Hours of Watkins Glen, where it ran with a long tail in the white, red and blue livery of the Brumos team, finishing seventh, and in the following day’s Can-Am race, where it came ninth.

With its works and Brumos duties completed, R7 was bought by Héctor Rebaque and raced in Mexico, in Viceroy Cigarettes colours, before entering the long-term ownership of Italian collector Massimo Baliva.

During this time, R7 kept such a low profile that it was long believed the car had been destroyed, leading to the creation of a convincing replica.

The Porsche 911 Carrera RSR’s huge rear wing is matched to 14in-wide wheels

When the original car came up for sale, litigation ensued, resulting in the replica being acknowledged for what it was, and the car we’re driving today has been authenticated by none other than Martini-Porsche’s 1973 team manager, Norbert Singer.

What Norbert would say about our on-track escapades today, I’m not sure.

He’d likely question why exactly we’re battling a sodden Goodwood hillclimb in this precious racer, rather than using the circuit just down the road.

But R7 is just too damned loud: it would melt the noise meters.

Porsche’s works racing cars used telescopic Bilstein dampers

Fortunately, there are no such restrictions on the Festival of Speed’s course, though the muddy slime left on its surface by service vehicles will keep us honest – especially since the rear tyres look more like cut slicks to me, and are of unknown provenance.

Nevertheless, approach the RSR from its rear three-quarter, and this has to be one of the most handsome (and compact) Le Mans titans ever conceived, evocative Martini stripes and all.

Neat features abound: twin fuel fillers – one for petrol, the other to release air pressure from the fuel cell during refills – are cut into the nose; metal clips retain the front and rear ’screens to avoid them popping out at speed; little chrome lights on each roundel illuminate R7’s race numbers; and, of course, the unfeasibly large but beautifully integrated ‘Mary Stuart’ wing, which provided such an essential downforce tool for the high-velocity circuits on which R7 raced.

The Porsche’s race-ready flat-six engine sounds great at any speed

There’s a vestige of production-911 dash ahead when you drop into the race bucket seat, pulling the door closed with a thin leather strap (that doubles as a pull-release).

Glance behind, and there’s former R7 pilot Gijs van Lennep’s signature on the central tunnel, from when he was reunited with the car at this year’s Le Mans Classic.

Otherwise, the cabin is as spartan as you like, right down to the worryingly slender diagonals of the rollcage bolted to the bare-metal floor.

‘This has to be one of the most handsome (and compact) Le Mans titans ever conceived, evocative Martini-Porsche stripes and all’

Four VDO clocks spread across the binnacle, showing fuel level, oil pressure and water temperature, along with a tachometer displaying a bold redline at 7000rpm and a speedo reading up to 300kph (186mph).

The near-vertical, three-spoke Momo Prototipo steering wheel is, I’m told, original.

It appears that R7’s key has been temporarily lost, so when the engine erupts into life, it’s thanks to the twist of a screwdriver in part of the ignition barrel.

And, boy, does it erupt.

The huge rear wing was dubbed ‘Mary Stuart’, after the collar ruff worn by Mary Queen of Scots

Even wearing a full-face helmet, you can’t hear yourself think – not helped by R7’s reluctance to idle at much less than 2000rpm.

But I defy anyone with a love of competition cars not to savour the aural glory of a full-race Porsche flat-six, at any revs.

Release the long-travel, floor-mounted clutch, and plenty of rpm are needed to prevent an embarrassing stall.

Anything less than 3000 and a bold throttle input has you kangarooing like a learner, so you grit your teeth and try to ignore the fact that big revs could equal big spins in these conditions.

The Porsche 911 Carrera RSR racing cars could hit 180mph down the Mulsanne Straight at Le Mans – we didn’t even attempt that at Goodwood

At lower speeds, the RSR wanders as aimlessly as a bored teenager and, with standing water on the track, it’s difficult to know if that’s down to a genuine lack of traction, or the steering’s inherent vagueness just off the straight-ahead – likely a bit of both.

But, as the rain subsides and the camera car pulls in, higher speeds give the RSR the direction that it needs.

All of a sudden, there’s more substance to the steering and a previously meandering gait gives way to something more planted and reassuring, despite the still-wet track.

R7 is the most original of the surviving R-numbered Porsche 911 Carrera RSRs

Full-bore assaults on the hillclimb’s straighter sections are now possible, though a weather eye is needed on the tachometer, such is the engine’s free-revving nature and surprising smoothness as it threatens to breach the 7000rpm redline.

Gearing is predictably tall through the long-throw, five-speed ’box, so we don’t see higher than third all day, but it’s enough to get a small measure of what R7 must have been like, hammering down the Mulsanne Straight at 180mph half a century ago, chasing down those pseudo-F1 cheaters.

Images: Max Edleston

Thanks to: Mark Gold and Jonathan Gill at Bonhams|Cars; Goodwood; Andy Prill

Factfile

Porsche 911 Carrera RSR
(specification for 3-litre works cars)

Sold/number built 1973/8
Construction steel monocoque, steel and glassfibre panels
Engine all-alloy, sohc-per-bank 2993cc, flat-six, Bosch mechanical fuel injection
Max power 330bhp @ 8000rpm
Max torque 232lb ft @ 6500rpm
Transmission five-speed manual, RWD
Suspension independent, at front by MacPherson struts rear semi-trailing arms; torsion bars, Bilstein telescopic dampers, anti-roll bar f/r
Steering rack and pinion
Brakes cross-drilled, ventilated discs with four-pot calipers
Length 13ft 6in (4128mm)
Width 5ft 5in (1651mm)
Height 4ft 4in (1321mm)
Wheelbase 7ft 5in (2271mm)
Weight 1850lb (839kg)
Mpg n/a
0-60mph 5.6 secs
Top speed 179mph
Price new DM59,000 (standard 2.8-litre Carrera RSR)
Price now £4.5-5.5m (R7)*