The Complete Book of Porsche 911
Page 19
Porsche’s BPR series GT3 and GT2 victories, while not quite so ubiquitous or overwhelming as those of its 935s 15 years before, very effectively sold Porsche competition cars to racers and series production models to enthusiasts. At the same time the company introduced the GT2, the Motorsports Department offered a lightened Carrera RS. It removed all insulation, replaced the front hood with an aluminum panel that was 7.5 kilograms (16 pounds) lighter, and substituted side and rear window glass, saving another 5 kilograms (11 pounds). With the same 102mm bore available to Exclusiv customers, the RS setup provided buyers with 300 DIN horsepower in a car that weighed 100 kilograms (220 pounds) less than the standard 993 Carrera 2 coupe. Its most significant innovation was a new engine induction system incorporating variable length intake tubes. This VarioRam system used vacuum-operated sliders to alter intake tube length by providing two intake tubes for each cylinder. Porsche tuned the longer one for maximum midrange torque. At about 4,400 rpm, the shorter one fed more fuel and air for horsepower and torque at higher engine speeds. Then, at 5,800 rpm, the system opened a large cross tube to provide optimal fuel-air mix for the highest engine ranges. The VarioRam not only smoothed out delivery of horsepower and torque, it also added to the driver’s enjoyment when engine tones changed as each induction path came into use. The new system was unique to the 1995 RS and its optional Club Sport variation.
Porsche had to manufacture 100 road versions of the car to gain homologation as a racer. This particular car came second in class in the 12 Hours of Sebring in 1995 and won its class in 1996.
With boost turned all the way up and minimal intake restrictor plates in place, the Typ M64/81 engine with 3,600cc displacement (219.6 cubic inches) developed as much as 550 horsepower at 6,000 rpm.
Porsche assembled 43 of these racers. They weighed 1,150 kilograms, 2,535 pounds. Bolted-on fender flares added 40mm (1.6 inches) to the cars width at front and 30mm (1.2 inches) at the rear.
Project manager Roland Kussmaul began developing the 993 Supercup cars as early as May 1993 to be ready for the 1994 season. Internally it was nicknamed the “Cup 3.8.” It rode 70mm (2.76 inches) lower than regular production coupes.
The 993 Turbo coupe arrived in spring 1995 at the Geneva Auto Show. The 959 had set a philosophical precedent for Porsche. Management decided that, with exceptions for racing homologations, any series production model providing more than 400 horsepower would have all-wheel drive. The 408-horsepower, 3.6-liter 993 Turbo, putting power to the front wheels as well as through the adapted Weissach rear axle suspension, delivered thrilling performance. Enthusiast magazines regularly recorded acceleration from 0 to 100 kilometers per hour in 4.4 seconds, and the cars topped out at 290 kilometers (180 miles) per hour. Porsche manufactured 2,457 through 1995, following the nine early production pilot cars assembled just before Christmas 1994. Porsche Exclusiv lived up to its name with two other limited edition projects, according to Porsche historian Marc Bongers. Throughout 1995, Exclusiv converted 14 993 Cabriolets into turbocharged open cars by using the 3.6-liter Turbo engine, five-speed manual gearbox, and brakes from the 964 models. In addition, the responsive customer service organization put together a single 993 Speedster for Ferdinand Alexander Porsche.
For the U.S. Supercup series, this car served as the pace car for 1995 events. It was tuned and developed at an equal level to the racers with stark interior and steel-tube roll cage. Cars accelerated from 0 to 100 kilometers per hour in 4.7 seconds.
For 1996 T Program cars, Weissach introduced the VarioRam across the entire normally aspirated lineup, providing them 285 horsepower at 6,100 rpm in street tune. For year-round cruising and touring drivers, Porsche revealed its new Targa. Instead of a fully removable roof panel, the car featured a large glass plate that slid down inside the rear window to open much of the cabin to the skies. Harm Lagaay had conceived this treatment in 1977 as one of his concepts when he designed the 924. The 993 Targa roof fixtures adhered to Wendelin Wiedeking’s requirement that outside suppliers deliver intact substructures ready for installation. Zuffenhausen assemblers mounted the roof system onto reinforced cabriolet bodies and welded side rails and front and rear mounts into place.
Porsche achieved another production milestone on July 15, 1996, when its millionth car rolled off the line. The company donated the coupe, fitted with the four-speed Tiptronic S transmission, to the Baden-Württemberg autobahn police in the company’s home district.
Porsche’s 993 Turbo body, with its larger brakes and wheels and tighter suspension, inspired product planners as it had with the 964. For 1996 they mated the Turbo body and running gear to the normally aspirated 3.6-liter engine and created the Carrera 4S. Porsche offered these cars with the manual transmission only. (For U.S. customers, Zuffenhausen fitted softer springs and shocks to improve ride quality over potholes.) V Program 1997 models saw the addition of the Turbo body look to rear-drive platforms (available with either the six-speed manual or four-speed Tiptronic S transmission) named Carrera S.
Intended for Le Mans, the GT2 Evolution ran with Porsche’s 3,600cc M64/83 engine that developed 600 horsepower at 7,000 rpm. The cars sold for 570,000DM, roughly $382,000 at the time. Photograph © 2011 Dave Wendt
To move the road-going benchmark a bit further out, Zuffenhausen’s Exclusiv program introduced the 430-horsepower Turbo S for 1997. Porsche claimed the cars reached 300 kilometers (188 miles) per hour and sold them for DM 235,000 (then $130,000). When the model reached U.S. markets in 1998, exchange rates reversed the advantages of earlier times, and Americans paid $155,000 for the S, whose production Porsche limited to just 199 units.
Alois Ruf took each Porsche performance introduction and raised the ante, starting in 1996 with a 993 Turbo-based R coupe developing 490 DIN horsepower. He quoted a top speed of 329 kilometers (204 miles) per hour from the DM 298,000 (about $184,000) coupe. Two years later he introduced his CTR II (narrow body) and CTR II Sport (Turbo body) coupes. These cars he characterized as the “modern successors” to his Yellow Bird. A full car-width rear deck lid supported a hollow rear spoiler that directed air to turbocharger intercoolers. Boasting 520 and 580 brake horsepower respectively, the CTR accelerated to 100 kilometers per hour in 3.6 seconds and topped out at 340 kilometers (213 miles) per hour. Ruf sold them for DM 425,000 (roughly $283,000) at the time. All-wheel drive added another DM 20,700 ($13,800) to the price.
Weissach engineers stretched another limit for 1998, fitting the GT2 flat six with engine management electronics derived from Porsche’s Formula One developments with Techniques-Avant Garde (TAG). This increased engine output to 450 DIN horsepower at 6,000 rpm and 430 lb-ft of torque at 4,500. Porsche assembled just 25 of these cars; buyers had the option of air bags, electric window lifts, and air conditioning on the rear-drive platform.
With an eye toward outright victory at Le Mans and in BPR events, Porsche created the 911 GT1 cars. To take advantage of everything the rules permitted, engineers mounted the engine ahead of the rear wheels that lengthened the wheelbase from stock 2,272mm (89.5 inches) to 2,500mm (98.4 inches).
The 3.8-liter M64/70 engine came from the Carrera 3.8 RS model, tuned in this case to develop 310 horsepower at 6,100 rpm. It ran on super-unleaded fuel and competed with its oxygen sensor and catalytic converter in place.
Stiffer springs and a new rear multi-link suspension greatly improved the handling of the Supercup cars. They weighed 1,100 kilograms, 2,420 pounds, complete with air-jack system.
The GT1 grew from stock 993 dimension in all directions. Compared with the production car overall length of 4,245mm (167.1 inches), the GT1 stretched 4,683mm (184.4 inches). At 1,946mm wide, it was 211mm wider (68.3 inches to 76.6 inches).
YEAR
1995-1997
DESIGNATION
911 GT2 and 911 GT2 Evo
SPECIFICATIONS
MODEL AVAILABILITY
Coupe Racing
Coupe Road
WHEELBASE
2272mm/89.4 inches
&nbs
p; LENGTH
4245mm/167.1 inches
WIDTH
1935mm/76.2 inches (race)
1855mm/73.0 inches (road)
HEIGHT
1300mm/51.2 inches (race)
1270mm/50.0 inches (road)
WEIGHT
1100kg/2420 pounds (race)
1295kg/2849 pounds (road)
BASE PRICE
$238,800 (race) – $193,007 (road)
$382,500 (EVO)
TRACK FRONT
1454mm/57.2 inches (race)
1475mm/58.1 inches (road)
TRACK REAR
1540mm/60.6 inches (race)
1550mm/61.0 inches (road)
WHEELS FRONT
10.0Jx18 (race) - 9.0Jx18 (road)
WHEELS REAR
11.0Jx18 (both)
TIRES FRONT
265/645-18 (race) - 235/40ZR18 (road)
TIRES REAR
305/645-18 (race) - 285/35ZR18 (road)
CONSTRUCTION
Unitized welded steel
SUSPENSION FRONT
Independent, light-alloy lower wishbones, MacPherson struts w/coil springs, gas-filled double-action shock absorbers, anti roll bar
SUSPENSION REAR
Independent, light-allow multi-wishbone, progressive coil springs, gas-filled double-action shock absorbers, anti roll bar (adjustable in car)
BRAKES
Ventilated, drilled discs, 4-piston aluminum calipers
ENGINE TYPE
Horizontally opposed DOHC six-cylinder Typ M64/81; Typ M64/83
ENGINE DISPLACEMENT
3600cc/219.7CID
BORE AND STROKE
100x76.4mm/3.94x3.00 inches
HORSEPOWER
450@5700rpm (race)
430@5750rpm (road)
600@7000rpm (EVO)
TORQUE
470lb-ft@5000rpm (race) – 398lb-ft@4500rpm (road)
479lb-ft@ 4,000rpm (EVO)
COMPRESSION
8.0:1
FUEL DELIVERY
Bosch Motronic TAGTronic fuel injection, twin turbochargers, intercoolers
FINAL DRIVE AXLE RATIO
Varies by circuit (race) - 3.44:1 (road)
TOP SPEED
Varies by final drive (race) - 167mph (road)
PRODUCTION
43 in 1994 (race) – 172 (road, between 1995 and 1997)
1996-1997 911 GT1
Porsche held a solid lock on GT2 and GT3 class wins, but overall victories in BPR’s endurance series went to premier category entrants racing in GT1. During the Peter Schutz years, engineers had grown accustomed to winning, and Norbert Singer knew the 911 GT2 needed better aerodynamics, greater downforce, and more horsepower to grab the lead. Rules required that the car have a flat bottom from its nose to the rear axle. Behind that point, Singer could create one or more venturi to hold the tail down. Following Porsche’s tradition of mounting the engine behind the rear axle severely limited the space available for these cavities. Singer and Herbert Ampferer reversed the engine, installing it ahead of the rear axle. BPR rules allowed longer wheelbases for GT1 entries, so they lengthened the GT2 from 2,270mm (89.4 inches) to 2,499mm (98.4 inches) for the new car.
BPR also required GT1 manufacturers to offer road versions of the car as well, though it became clear that a single car or two might satisfy the regulators. Starting in 1995, engineer Horst Reitter worked with Singer to establish package specifications, including steering, suspension, engine, drivetrain, cooling, and cockpit. Reitter incorporated the production 993 front end because it already had passed German and U.S. crash tests, necessary for the single road car’s homologation. This allowed him to install the 993 instrument panel as well. One requirement from Porsche Supervisory Board was more challenging than the BPR specifications: The car had to be “identifiable as a 911 at first glance.”
That job fell to 993 stylist Tony Hatter. At first Norbert Singer was not thrilled working with the Design Department. Singer, a man with decades of hands-on experience, was skeptical, and Hatter had to do much of his work when Singer left the room. Then he learned that styling had computer technology that let them build cars digitally. Singer and Hatter created shapes and milled them into three-dimensional wind tunnel models very quickly. Hatter lengthened the 993 and widened it to accommodate racing tires. Together they invented Porsche’s first mid-engine 911. The board approved it in late July 1995 for the 1996 racing season.
While the production 993 stood 1,300mm tall (51.2 inches), the GT1 hunkered down to 1,173mm (46.2 inches). It weighed just about 1,000 kilograms, 2,200 pounds. Porsche’s GT1s finished second and third overall at Le Mans in 1996.
Alois Ruf developed his Turbo R based on Porsche’s 993 Turbo model, fitting the car with firmer springs and larger anti-roll bars and altering shock absorber characteristics.
It required substantial effort to fit the production nose over Reitter’s racing suspension. Herbert Ampferer took on power train development, revising the successful 962 engines with their 95mm bore and 74.4mm stroke for a total displacement of 3,164cc (193.0 cubic inches). He water-cooled the entire engine. For the single road-going example for homologation, Weissach installed a standard 3.3-liter (201.3-cubic-inch) Carrera engine tuned to produce 300 brake horsepower. But development continued on the racing models. Jürgen Barth drove the first prototype in mid-March, barely a month before the Le Mans April trials.
Ruf mounted 18-inch alloy wheels. Acceleration from 0 to 100 kilometers per hour took 3.6 seconds. With appropriate gear ratios, top speed was 329 kilometers (204 miles) per hour.
Singer and his staff tested the car extensively, running up nearly 2,000 kilometers (1,200 miles) in a single five-day test. Porsche entered chassis 001 and 002 at Le Mans in June 1996. When the race ended, 002 had taken first in the GT1 class, second overall behind Reinhold Joest driving a Porsche-powered prototype.
Porsche fielded dozens of orders for the road car, which slowed only when Barth informed potential customers they were getting a 300-horsepower street engine, not the 600-horsepower Le Mans version. Meanwhile, privateers placed requests for the competition model. The racers weighed 1,058 kilograms (2,328 pounds), and with long gears for Le Mans, they reached 375 kilometers (235 miles) per hour. Porsche had created yet another out-of-the-box success. At Brands Hatch in England, Spa in Belgium, and Zuhaï in China, car 001 or 002 took first place. Then Weissach went to work filling nearly 30 solid orders for racing and road versions of the car known as GT1/96. Porsche set a price of DM 1,550,000 ($1 million) for the racers and DM 1,400,000 (roughly $890,000) for road cars, which ultimately ran 544-horsepower engines, not the lesser homologation motors. Paul Frère, writing in Road & Track magazine, put the road version in context: Private individuals will buy the GT1, he wrote, “for the pleasure of driving the closest possible thing to a full-blooded, very high performance racing car.” This taught Porsche another marketing lesson.
Small touches were everywhere in the interiors. Ruf instruments provided green markings. His steering wheel contained an airbag, and he re-contoured the sports seats.
The water-cooled Typ M96/80 engine, with 95mm (3.74-inch) bore and 74.4mm (2.93-inch) stroke, displaced 3,163cc (192.9 cubic inches). It developed 600 horsepower at 7,200 rpm.
With competition increasing in the rarified GT1 category, Porsche decided to support its 30-some customers with updates and a new version, the GT1/97. Norbert Singer made enough changes that Porsche had to create a 1997 GT1 road car as well, picking up styling cues from the next generation 911. Sanctioning body BPR yielded authority to the FIA, which offered to run an 11-race series for 1997.
It was a less successful season for Porsche. With losses to Mercedes-Benz and McLaren, Singer, Barth, and their customers knew victory in 1998 required an all-new car. Using carbon fiber for the chassis saved 90 kilograms (200 pounds), which everyone felt was necessary. Wiedeking agreed, and he sanctioned GT1/98. But a new 911 was coming as well, with a new look and new engine, and any Porsc
he race car that had “to be identifiable as a 911 at first glance” had to reflect this new appearance.
Engineer Hans Reitter conceived of using the lower section of the production 933 front end. Rules required for manufacturers to sell road-going versions of these racers meaning they had to survive a crash test. That left a race car interior that looked familiar to most Porsche drivers.
1998 Ruf Turbo R Cabriolet
Alois Ruf was concerned about putting such performance potential into an open car without his typical roll cage. But this longtime customer convinced Ruf this car was for sunny day drives along the California coast.