My mobile rings. “Are you in Greggs?” asks my wife, imagining that I am breakfasting with my snapper before getting down to work. Well yes, I am in Gregg’s, but not one of the UK’s eponymous café-cum-bakery chain’s eateries. No, I’m seated in a way more revered and exclusive Gregg’s, that of the late Peter Gregg, the very 911 2.8 Carrera RSR that trounced most of the opposition in Trans-Am and IMSA back in 1973.
Resplendent in its newly-restored Brumos livery, it was present at the Rennsport Collective gathering at the Donington Park circuit in Leicestershire, England, brought over from Europe by specialist Porsche entrepreneur Kobus Cantraine. It was one of a few dozen famous road-and-race Porsches participating in a light-hearted frolic around the grounds of Castle Donington, rather in the manner of the Goodwood Festival of Speed. Ahead of it, I treated myself to a few laps behind the RSR’s wheel on Donington’s marvelous blacktop.
Conceived in 1973 to contest the international sports racing category, where it was hoped it would be quick enough to go head-to-head with the Ferrari and Matra prototypes, the 911 2.8 Carrera RSR was a quantum leap from the road-going 2.7 Carrera RS. The suffix RSR stood for Renn Sport Rennen, or Motor Sport Racer. Porsche needed to build 50 units of the RS for homologation so the RSR race car could have a legitimate basis. They then made 49 RSRs, of which this Brumos car is one.
The original 2,808 cc RSR, with its stripped-out cabin and built-in roll-cage, weighed 1,984 lbs and developed 300 hp at 8,000 rpm. It had high-compression pistons, twin-plug ignition, a bigger fuel injection pump, wider wheels and tires, flared wheel arches, plus a pert ducktail spoiler integral with the engine lid, a carry-over from the 2.7 RS.
To arrive at 2.8-liters, the bores of the 2.7-liter flat-six’s barrels were increased 2.0 mm (.08 in.) to 92 mm (3.6 in.) and paired with the 2.7’s 70.4 mm (2.77 in.) crank. The six was then allied to the 2.7’s five-speed , but with alternate ratios available. Its drilled and vented brakes came from the 917, and its bulbous fenders housed 9J and 11J x 15 inch Fuchs wheels.
The 2.8 RSR you see here, #911 360 0727, arrived in the U.S. in April 1973 for delivery to the Jacksonville, Florida-based Brumos Racing to be driven by Peter Gregg, by then a racing hero with many SCCA and Trans-Am racing wins. It was specially built at Weissach with the aim of Brumos capturing both IMSA and Trans-Am series championships. Upgraded specifications included larger diameter shock towers to allow the fitment of new titanium coil-over racing dampers and more rigidity, and body panels—including the roof and doors—made from thinner gauge steel. A 3.0-liter engine became available later on in the season.
Supervised by Porsche senior race engineer Norbert Singer, Peter Gregg and Hurley Haywood had already won the 1973 Daytona 24-Hours with 2.8 RSR #911 360 0328 on February 4th, 1973 by virtue of reliability over the faster Matra and Mirage 3.0-liter prototypes and better performance than the Corvettes, Camaros, and Daytonas. In fact, the RSRs had yet to receive Commission Sportive Internationale (CSI) homologation approval and had entered as prototypes.
A second “factory” 2.8 RSR provided to the Penske-Sunoco team and driven by Mark Donohue and George Follmer led for five hours, but retired with a holed piston, giving the Brumos car a 35-lap lead with nine hours remaining. Despite having a seagull shatter their RSR’s windscreen, Gregg and Haywood took the victory. It was the first major international win at this level for a 911-based race car. Gregg and Haywood went on to win at Sebring in another 2.8 RSR (#911 360 0705) just a few weeks later.
The season’s results speak for themselves. Peter Gregg won both the IMSA GTO and Trans-Am titles in 1973 with the car you see here. Though Gregg only won one of the six rounds of the 1973 Trans-Am (Road Atlanta), he amassed enough points to bring home the title, with Al Holbert in second, ahead of the Camaro and Corvette opposition.
In the 1973 IMSA series, Gregg (paired with Haywood for some but not all victories) won six out of ten rounds, including Daytona, Sebring, Lime Rock, and Road Atlanta. Gregg was undoubtedly the class of the field, but the serious advantage he had with the uniquely prepared Brumos RSR was paramount. By way of thanks for the results achieved, Porsche sold Gregg #360 0727 at the end of the season for just $1. Yes, one dollar.
Moving on, for 1974, the RSR had a stronger aluminum crankcase and bigger pistons and barrels, taking it up to 3.0-liters and 315 hp, plus slide-valve fuel injection. The wheel and tire width was broadened to 10.5 inches in front and 14.0 inches in back, accommodated by bulging fiberglass fender flares, with air vents slashed in the trailing edges of the front fenders and ahead of the rear wheel arches. It was fronted by an air-dam with an integral oil radiator and a pair of air ducts and finished off with a whale-tail rear wing. The factory used several cars as aerodynamic mules in preparation for the launch of the 3.0-liter 934 and slant-nose 2.8-liter turbocharged 935.
The best result for the RSR at an international level in 1975 was the Daytona 24-Hours, where Gregg and Haywood won that event in Brumos 3.0 Carrera RSR #911 460 9054, crossing the line ahead of five other RSRs. Yes, RSRs took places one through six overall. Our feature car, by then sold by Gregg to Charlie Kemp, finished third with Kemp and Carson Baird at the wheel. All told, Gregg, driving Brumos RSRs won the IMSA GTO title three years running, from 1973 to 1975.
New Appendix J racing regulations for 1976 meant the creation of two separate series, the World Championship for Makes (for the Group 4 GTs and Group 5 “Special Production” cars) and the World Championship for Sports Cars (for Group 6 prototype racers). Both were effectively ‘silhouette’ formulas, meaning the cars looked like their road-going counterparts but shared relatively few similarities beneath the surface.
Porsche built the 934 for GT racing and the 935 for the Group 6 Sports Car category. The RSR soldiered on for a few more seasons, known simply as a Carrera, contesting the Group 5 and IMSA categories. In 1977, an RSR (#911 560 9112) again won the Daytona 24 Hours, this time with Hurley Haywood, John Graves, and Dave Helmick taking turns at the wheel. The RSR remained a popular mount for the IMSA GTO class from 1978 until 1981, when turbocharged 934s were admitted. In 1974, RSR #360 0727 was sold to the abovementioned Charlie Kemp, who raced it in 1974 and 1975. It was then sold via broker George Valerio in 1976, going to Dan McLaughlin in 1979, thence via John Starkey to Frenchman Jean-Philippe Grand.
When stripped for inspection in more recent times, the special Porsche factory developments body reinforcements and the larger size rear shock towers were found to be still in place. The car was prepared for European historic racing, an FIA Historic Technical Passport was issued, and the car competed successfully in several high-profile races, including a victory for J-P Grand at the Mugello Classic in 2014. The car was then sold to its current owner, and a bare metal restoration was undertaken, during which, #360 0727 was rebuilt to its original Brumos 2.8 RSR specifications.
The Drive & Verdict
Located in the English Midlands, Donington Park goes back to the 1930s, hosting the hard-charging Mercedes and Auto Union Silver Arrows in the 1937 and 1938 Grands Prix seasons. Its finest hour in more recent times was in 1993 when it hosted the European Grand Prix in which Ayrton Senna trounced all the F1 opposition in conditions more suitable for a powerboat. And now it’s my turn to channel the actions of Peter Gregg and Hurley Haywood on the Donington track.
I’ve previously driven two 2.8 RSRs (an ex-Max Moritz car #911 360 0636, and the ex-Juan-Carlos Bolanos car #911 360 1099), so I have an idea of what to expect. With a slight clunk to get into first gear, the clutch is phenomenally fierce, demanding a left-calf workout to depress and release. The left footrest is way off the uncarpeted floorpan. On the move, it doesn’t disappoint, dispensing a heady cocktail of raw speed, peerless handling, and aggressive appearance. It’s hugely exciting yet compliant. Power delivery is instantaneous and enormous from low revs right through the range.
The RSR’s engine is a roarer, its crescendo snarling to a sustained scream, and lift-off prompts a wonderful rasping overrun. Drivability is acutely evident in the fluent gearshift from second to fifth, and it positively romps through the ups, downs, and hairpins. It really must have been a lot of fun back in the day, being in Gregg’s. In his 2.8 RSR, at any rate.
A caricature of the 2.7 RS, the 2.8 RSR is on a different level to its forebear. The suspension is tauter, so there’s less body roll. The tires are large for an early 911 (Michelin Corse 215/55R15-79 in the front, and 270/45R15-86V in back), so there’s much more confidence-inspiring grip. And while the 2.7 is a linear engine that pulls strongly, the RSR’s 2.8 revs much more easily, whizzing right round the rev band. It’s a little bit torquier too, and I strongly sense its race car nature. There’s a fluency about it, and everything is crisp and sharp, as you’d expect after a major overhaul. It’s every bit the ultimate early 911 you would hope it would be.