The Complete Book of Porsche 911
Page 7
Demand for the car pleased the sales staff based in Ludwigsburg, and it taught them a valuable lesson: Porsche owners were devoted to the marque. Something unique was desirable, and they were willing to pay to be part of a small group who could get a Carrera RS.
It was all about exclusivity, and while the company had just recognized it as a marketable option for outsiders, it had been creating special cars for insiders since the beginning. By 1973 Customer Service, Sonderwunsch (Special Wishes), and other departments had produced a dozen or more unique 356s and 911s for Porsche and Piëch family members. Out of the run of 1973 RS Carreras, a special car for Ferry Porsche, painted Silver Green Diamond Metallic, appeared. According to RS Carrera historian Georg Konradsheim, the car boasted a blue cloth-and-leather interior and, in a hint of styling director Tony Lapine’s ultimate plans, body color or flat black trim. The side Carrera logo was silk-screened in green. Instead of the Carrera’s signature Fuchs wheels, this car had ATS “cookie cutters,” also in green. Under the rear deck lid, the car ran with a 2.8-liter engine with a forerunner of Bosch’s K-Jetronic continuous fuel injection, which appeared on series production cars half a year later. Ferry drove the car regularly until 1975. It disappeared for decades but ended up in the significant collection that historian Konradsheim has built outside Vienna, Austria.
The absolute truth of value recognized and value paid for held for competitors too. Norbert Singer’s Racing Department completed 57 RSR 2.8 models. Porsche charged DM 59,000 for the race car, $22,500 delivered in the United States (or about DM 25,000—$8,930—more than the lightweight RS production model). To create the cars, Singer’s mechanics steered RS H homologation cars off Zuffenhausen assembly lines without engines or transmissions. They rolled them from the assembly plant to the former racing shops in Werke I, an area designated for customer service after the Competition Department had moved into Weissach. Once inside the old brick building, mechanics installed engines that Hans Mezger had bored an extra 2mm to 92mm, which gave total displacement of 2,806cc, or 171.2 cubic inches. Mezger’s engineers installed cylinder heads that increased compression, used larger valves, and used a twin spark plug ignition. Porsche rated these engines at 300 horsepower DIN (about 286 SAE net) in a car weighing 852 kilograms, or 1,875 pounds.
The 2.8 RSR racing debut took place at the Tour de Corse in November 1972, but things didn’t go well. Singer, Mezger, and their staffs worked throughout the winter to correct problems. Martini & Rossi signed a three-year sponsorship contract. The 1973 season began at Daytona, Florida, in early February, toured Europe through the spring and early summer, and concluded in late July at Watkins Glen, New York.
The new 2.7 liter 2,687cc (163.9-cubic-inch) Typ 911/83 flat six used Bosch mechanical fuel injection to help reach output of 210 horsepower at 6,300 rpm. One of the car’s most outstanding exterior details was its burzel, or ducktail spoiler.
Porsche offered the RS Carrera in 13 standard and 16 special-order colors. The company assembled just 62 in black. Curiously, records suggest most black cars were shipped to Central and South America.
Touring versions accelerated from 0 to 100 kilometers in 6.3 seconds, compared with the lightweight cars that reached 100 in 5.8 seconds. Both models sold for 34,000DM, $12,830 at the time.
Deleting the clock from the fifth instrument pod saved grams and ounces, as did removing the glove box cover and using a leather pull strap to open the door from the inside. Porsche listed weight at 960 kilograms, 2,112 pounds.
Touring versions weighed 1,075 kilograms (2,365 pounds), which was 115 kilograms (253 pounds) more than the lightweight models. These received inner door panels, glove box covers, radios, clocks, sun visors, and reclining seats.
YEAR
1973
DESIGNATION
911 Carrera RS
SPECIFICATIONS
MODEL AVAILABILITY
Coupe: Lightweight M471; Touring M472
WHEELBASE
2271mm/89.4 inches
LENGTH
4147mm/163.3 inches
WIDTH
1652mm/65.0 inches
HEIGHT
1320mm/52.0 inches
WEIGHT
920kg/2024 pounds (M471 Lightweight)
1075kg/2365 pounds (M472 Touring)
BASE PRICE
$13,094 Lightweight - $13,774 Touring
TRACK FRONT
1372mm/54.0 inches
TRACK REAR
1394mm/54.9 inches
WHEELS FRONT
6.0Jx15
WHEELS REAR
7.0Jx15
TIRES FRONT
185/70VR15
TIRES REAR
215/60VR15
CONSTRUCTION
Unitized welded steel
SUSPENSION FRONT
Independent, wishbones, MacPherson struts, longitudinal torsion bars, hydraulic double-action shock absorbers
SUSPENSION REAR
Independent, semi-trailing arms, transverse torsion bars, hydraulic double-action shock absorbers
BRAKES
Discs, 2-piston aluminum-front cast iron-rear fixed calipers
ENGINE TYPE
Horizontally opposed DOHC six-cylinder Typ 911/83
ENGINE DISPLACEMENT
2687cc/163.5CID
BORE AND STROKE
90x70.4mm/3.54x2.77 inches
HORSEPOWER
210@6300rpm
TORQUE
188lb-ft@5100rpm
COMPRESSION
8.5:1
FUEL DELIVERY
Bosch mechanical fuel injection
FINAL DRIVE AXLE RATIO
4.429:1
TOP SPEED
152mph M471 Lightweight - 149mph M472 Touring
PRODUCTION
17 homologation; 200 M471 Lightweight; 1,308 M472 Touring
1973 CARRERA 2.8 RSR
During the April trials for Le Mans, Norbert Singer ran the cars with 11- and 12-inch wheels. Shortly afterward, loopholes in regulations—and a well-timed protest from a competitor—allowed Singer to run the RSR as a prototype. This gave him considerable freedom to develop new tricks. As a prototype for the 24-hour race in June, Singer fitted the cars with 15-inch rear tires.
Wider tires, wheel flares, and a huge rear wing slowed the cars’ top speeds, to Ernst Fuhrmann’s chagrin. Yet these same changes improved cornering, so lap times didn’t change and the wider tires lasted longer. Still Fuhrmann was irked. How was it that he, an engine man, gave Singer more power and still the car was slower on the straights? “Okay, tell the drivers we race flat out from the first lap. Twenty-four hours,” Fuhrmann ordered. Singer predicted a short race. But Porsche’s bulletproof engines and chassis ran a near sprint and still finished 4th, 8th, and 10th overall. By the end of the season, the production-derived 911 Carrera RSR 2.8 had won the manufacturers and drivers championships, beating pure sports prototypes from half a dozen competitors. Series production reached 14,714 cars, a near record. Ernst Fuhrmann, Norbert Singer, Wolfgang Berger, and a host of Weissach engineers and designers breathed life back into a car their predecessors had sentenced to death. What few people outside of Weissach knew was what else the engineers had in mind.
“Racing must have a connection to the normal automobile,” Fuhrmann explained in 1991. When he rejoined Porsche, its turbocharged Can-Am and InterSeries racers had built a legend of flawless performance and relentless victory. “So I said to my people, why don’t we put this success into our series production cars?”
There had been attempts earlier. In 1969 Valentin Schäffer had mounted turbochargers onto a couple of the 2-liter engines. He installed one in a 911 and the other in a 914/6. Because engine compartment space was tight in each vehicle, the turbo hung outside the body of the 911 and developed serious heat dissipation problems on the 914/6. Long tubes required to channel exhaust to spin the turbines, coupled to more long tubes necessary to get the pressurized fuel mix into the engines, caused tremendous turbo lag. Schäffer
assembled another prototype and had it running in April 1973. It still suffered turbo lag, and the 911 chassis struggled to handle 250 brake horsepower. Fuhrmann told his engineers not only that it had to work but that it had to function with the new Bosch K-Jetronic electronic fuel injection that Paul Hensler’s engineers had coming on the midyear 911T.
The Bosch system appeared through the entire 911 lineup for 1974. Schäffer made it work on his turbocharged prototypes by bringing air through the K-Jetronic, upward past its metering valve, and then into the compressor side of the turbo. This forced the condensed fuel-air mix to the throttle valve above the engine’s new cast-aluminum intake manifold. He and Hans Mezger passed the project along to Herbert Ampferer and Robert Pindar to make it production ready, a process with its own challenges.
Race drivers keep their feet hard on the gas pedal until the instant they brake. They drive through the same turns and straights repeatedly, and they develop a rhythm to keep the turbocharger spinning fast for instant response. Sometimes this involves keeping a foot on the gas pedal while braking. Racers don’t coast, and they don’t cruise at a steady speed limit. The “partial throttle” condition in production cars is one that allows the turbo to slow down. When the driver needs power and floors the gas pedal, the engine horsepower may double within seconds, but only after a delay. Modulating these dramatic differences required months of experiments, tests, adjustments, and more tests.
Porsche engineer Jürgen Barth co-drove this car with Georg Loos to finish 10th overall at Le Mans in June 1973. Together they averaged 177 kilometers (111 miles) per hour to cover 4,249 kilometers, 2,656 miles.
Porsche assembled something like 57 of these RSR models. While the front wheels were 9 inches wide, the rears were 11. They weighed 900 kilograms, 1,980 pounds.
At the Frankfurt show in September 1973, Porsche showed the results, introducing its production Turbo Coupe to an incredulous audience. Weissach designers and engineers created a silver coupe with RSR flared front and rear fenders that housed wide tires. They finished the car with a large flat rear wing and graphics that stretched the word “Turbo” from the top of the rear wheel arches to the taillights. Motor show enthusiasts who had watched the 917 Can-Am and InterSeries cars race found this new automobile irresistible. Printed materials boasted that Porsche had pulled 280 DIN horsepower (about 267 SAE net) out of its 2.7-liter engine. The car had race car looks and promised race car performance, and regular customers could buy it.
Known inside Porsche as Option M492, the car came with brakes from the 917 race cars, a roll bar, flared fenders, and a $24,000 price tag to competitors in the United States.
Engineers increased bore from 84mm (3.31 inches) to 90mm (3.54 inches), which enlarged overall displacement to 2,806cc (171.2 cubic inches). This Typ 911/72 engine developed 300 horsepower at 8,000 rpm.
YEAR
1973
DESIGNATION
911 Carrera 2.8 RSR
SPECIFICATIONS
MODEL AVAILABILITY
Coupe
WHEELBASE
2271mm/89.4 inches
LENGTH
4147mm/163.3 inches
WIDTH
1680mm/66.1 inches
HEIGHT
1320mm/52.0 inches
WEIGHT
900kg/1980 pounds
BASE PRICE
Not available
TRACK FRONT
1402mm/55.2 inches
TRACK REAR
1421mm/55.9 inches
WHEELS FRONT
9.0Jx15
WHEELS REAR
11.0Jx15
TIRES FRONT
230/600-15
TIRES REAR
260/600-15
CONSTRUCTION
Unitized welded steel
SUSPENSION FRONT
Independent, wishbones, MacPherson struts, longitudinal torsion bars, hydraulic double-action shock absorbers
SUSPENSION REAR
Independent, semi-trailing arms, transverse torsion bars, hydraulic double-action shock absorbers
BRAKES
Discs, perforated, with aluminum alloy calipers
ENGINE TYPE
Horizontally opposed DOHC six-cylinder Typ 911/72
ENGINE DISPLACEMENT
2806cc/171.2CID
BORE AND STROKE
92x70.4mm/3.62x2.77 inches
HORSEPOWER
300@8000rpm
TORQUE
217lb-ft@6500rpm
COMPRESSION
10.3:1
FUEL DELIVERY
Bosch mechanical fuel injection
FINAL DRIVE AXLE RATIO
Depends on circuit
TOP SPEED
Depends on final drive
PRODUCTION
57
1974 CARRERA 3.0 RSR
The Carrera served as the foundation of the next generation of Porsche’s actual race cars as well. FIA regulations restricted competitors in the Manufacturers Championship to a “silhouette formula”; while modifications to the engine, brakes, transmission, suspension, and even interior and chassis were allowed, the car had to look like one available at a dealership. At circuits around the world, Porsche’s RSR 2.8- and 3.0-liter cars won events, captured season titles, and inspired entire racing series. In the United States, Roger Penske, who had run Porsche’s 917-30 Can-Am program in 1972 and 1973, ordered 15 identically equipped RSRs for a series he and Riverside Raceway owner Les Richter named the International Race of Champions (IROC). Four events challenged a collection of drivers invited from sports car racing, NASCAR stock cars, and Indianapolis open-wheel racing. Norbert Singer and Ernst Fuhrmann created the IROC cars by blending pieces from RS 3.0 bodies and RSR 3.0 engineering, all wrapped in a wild array of colors. The bodies, shipped to the United States with bürzel ducktails, ran the races with Porsche’s new “whale tail” flat rear wing and bore an intentionally strong resemblance to series production cars. It worked to entice Sunday race spectators to become Monday dealership customers. Buyers couldn’t get the IROC 316-horsepower engine, and they may not have desired the Day-Glo colors, but they could buy something close.
YEAR
1974
DESIGNATION
911 Carrera 3.0 RSR
SPECIFICATIONS
MODEL AVAILABILITY
Coupe
WHEELBASE
2271mm/89.4 inches
LENGTH
4235mm/166.7 inches
WIDTH
1680mm/66.1 inches
HEIGHT
1320mm/52.0 inches
WEIGHT
900kg/1980 pounds
BASE PRICE
Not available
TRACK FRONT
1472mm/57.6 inches
TRACK REAR
1528mm/60.2 inches
WHEELS FRONT
9.0Jx15
WHEELS REAR
11.0Jx15
TIRES FRONT
230/600-15
TIRES REAR
260/600-15
CONSTRUCTION
Unitized welded steel
SUSPENSION FRONT
Independent, wishbones, MacPherson struts, longitudinal torsion bars, hydraulic double-action shock absorbers
SUSPENSION REAR
Independent, semi-trailing arms, transverse torsion bars, hydraulic double-action shock absorbers
BRAKES
Discs, perforated, with aluminum alloy calipers
ENGINE TYPE
Horizontally opposed DOHC six-cylinder Typ 911/75
ENGINE DISPLACEMENT
2994cc/182.7CID
BORE AND STROKE
95x70.4mm/3.74x2.77 inches
HORSEPOWER
330@8000rpm
TORQUE
231lb-ft@6500rpm
COMPRESSION
10.3:1
FUEL DELIVERY
Bosch mechanical fuel injection
FINAL DRIVE AXLE RATIO
Depends on circuit
TOP SPEED
Depends on final drive
PRODUCTION
69 (including 15 for IROC Series US)
1974-1975 911
Porsche simplified its G series model lineup for 1974. The company dropped the T and E models, offering instead a single 150-horsepower DIN (143 SAE net) coupe or Targa 911 as a base model. This sold for DM 27,000 in Germany, $9,950 in the United States. Next up the scale was the 911S with 175 horsepower (167 SAE net). It went for DM 31,000 and $11,875. European markets could get a 210-horsepower DIN Carrera model with the same engine as 1973 models. Porsche fitted the 167-horsepower S engine to Carreras bound for America’s shores to meet emissions regulations. The company priced the Carrera at DM 38,000, or $13,575.