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The cars that made
Porsche history

by Bill Oursler
Page 2

Type 917
Production Cars

The type 917

Of all of the historic racing Porsches, without doubt the best remembered, and the most important was the Porsche 917 which debuted in 1969 as a 4 5-liter, 550 horsepower, twelve-cylinder version of the 908. In 1970, the developed 917 not only brought Zuffenhausen its second straight World Makes crown, but its first ever, outright victory at Le Mans. In subsequent seasons, the coupe would be transformed into a 1000 HP. turbocharged, open topped Spyder that would come to dominate the North American Can-Am series much in the same fashion as it had the endurance scene. In short, the 917 was a watershed car that put Porsche in the center stage spotlight of motorsport.

Piech and his group created the 917 after discovering a rules loophole big enough to sink 20 Titanics That regulatory miscue permitted so-called "production" 5.0-liter sports cars, of which at least 25 identical examples had to have been made, to run in the Manufacturers title chase. The idea that this figure would permit such aging vehicles like the Lola T-70 coupe and the Ford GT-40 to flesh out the relatively slim 3.0-liter prototype ranks in the championship. Never did anyone think that someone would go to the trouble of building 25 expensive prototype-like vehicles simply to qualify them as "production" legal.

Yet, in the spring of 1968 that's exactly what Piech and Porsche decided to do. The reasoning behind the decision was not complicated, since Porsche already was building twice that many competition cars a year to meet the internal decree that new racers would be used by the factory for every event. Further, Piech reasoned that the 917 wouldn't have to be created from scratch, but could be developed from the just introduced 908 eight-cylinder.

In fact, while the 917 was largely new, much of its major components could be traced to the 908. This included its awesome twelve-cylinder powerplant that kept the 908's basic head design, injection system, and bore and stroke dimensions. New was the central power pick up arrangement which effectively created two six cylinder crankshafts tied together - thus eliminating the torsion problems found with a more conventional arrangement. Fortunately, from the start, the engine, which would eventually be produced in 4.9, 5.0 and 5.4-liter displacement variants worked well from the beginning.

Less successful was the transformation of the 908's chassis that kept its overall shape and wheelbase. The only real changes were the substitution of a detachable tsail that permitted the car to be raced either as a "langhect" or in "Kirtz" fashion, as well as the placing of the driver slightly further toward to accommodate the extra length of the new flat 12. Unhappily, while the 908 was fairly stable, the 917 was not, especially approaching the 220 plus mile-an-hour speeds of which it was capable.

Ultimately, this was traced to an aerodynamic problem that caused the rear of the car to lift creating severe high speed oversteer. Testing produced the upraised wedge tail shape that came to so characterize the tamed 917K models, this being discovered during a post 1969 shakedown run conducted by Porsche and the Gulf Wyer team which was to represent the factory in 1970-71.

With its aerodynamics corrected, the 917 went on to dominate the World Championship of Makes against the almost equally awesome 5 0-liter Ferrari 5l2. Likewise the 25-example "production" sports car by the Italian marque. Ironically, while the 917 won Le Mans both years, it wasn't the Wyer team that triumphed. Instead, the Porsche Salzburg team belonging to Piech's month Louise, with Englishman Richard Attwood and longtime factory driver Hans Kerrmann driving scored the initial victory. Hans Kerrmann retired after the event.

The second win came at the hands of the Martini team that succeeded the Porsche Salzburg operation in 1971. Interestingly, despite the fact that Porsche had developed a special long tail version of the 917 for Le Mans with a top speed of nearly 250 miles-an-hour, the two victories were scored by short tail 917K's. That latter performance came with a magnesium-framed version, which was used as a testbed for what Porsche hoped, would be its 1972 Can-Am challenger.

As far back as 1969, Zuffenhausen had become involved in the Can-Am when, at the urging of its North American racing boss, Josef Hoppen, it created an open-topped version of its endurance coupe for the championship. Although the car was overweight and under powered, Jo Siffert drove it to fourth place in final point standings. Later four more coupes were cut down to race in the European-based Can-Am counterpart, the Interserie that would eventually become a 917 preserve.

In the spring of 1971 Piech and Porsche became seriously interested in the Can-Am, producing a revised version of the 917 Spyder dubbed the 917/10. Lighter in weight, this was intended to utilize a turbocharged 5.0-liter twelve-cylinder, but initialed appeared in Siffert's hands during 1971 with a non-boosted engine instead. Again, despite a power handicap, Siffert took fourth in the standings.

Unfortunately, the Swiss was killed before the end of the season in a Formula One accident. Originally Porsche had planned to involve Siffert in the '72 Can-Am as a back up to Mark Donohue who would spearhead Porsche's efforts in the Roger Penske L&M sponsored 917/10. In the end, Penske alone represented the factory, although numerous privateers raced non-turbo versions of the Spyder both in the Can-Am and the Interserie during the 1972 campaign.

Porsche had little trouble defeating the reigning McLaren's in North American, and equally little problem capturing the Interserie. However, Donohue would have to wait a year for the Can-Am driver's crown, having been put out of action for most of the year after a testing accident at Road Atlanta. Donohue injured his knee when the tail section came off his car, causing it to flip violently; instead substitute George Follmer garnered the honors.

Donohue would return in 1973 using a revised Spyder, the 917/30 that featured a longer wheelbase and revised aerodynamics. Powered by a 5.4-liter turbo, the Sunoco Oil company-backed entry was capable of 240 MPH in a straight line. Although the first two Can-Am rounds went to privateers using the previous year's 917/10, Donohue came back strongly, winning everything else from the third race on. At the end of the season he announced his retirement, while the SCCA forced the withdrawal of the 917 from Can-Am competition by drastically reducing its fuel supply, forcing it to race at noncompetitive boost pressures.

Still, the saga of the 917 wasn't quite finished. While it raced on in the Interserie, winning the 1974 crown and helping Porsche to take the 1975 championship, it also made one more Can-Am appearance. That came at Mid Ohio in 1974 when Brian Redman took the Penske 917/30 to a second place behind the Shafdow Chevrolet of Jackie Oliver. In 1975, ten days before his tragic death during practice for the Austrian Grand Prix, a now un-retired Donohue used that same car to set a new closed course speed record of more than 221MPH at the high banked 2.5-mile Talladega Tri-oval, and, that still wasn't it. In 1981, the Kremer brothers entered a 917 endurance coupe copy in the Makes series, the car showing great competitiveness in spite of its aged design.

The Production Cars

After it put aside the Gmund coupes following the 1954 season in favor of the competition-oriented 550 Spyders, Porsche did not totally abandon the production car arena. During the latter part of the 1950's Zuffenhausen installed four cam Carrera four-cylinder powerplants in a number of different 356's specifically so that its customers would have something to run in the production categories. Included were both the open-topped Speedsters and their coupe counterparts, some of these cars remaining competitive enough to win in North American SCCA Regional and National club events up through the 1980's.

The ultimate expression of the 356 production racer was the Carrera Abarth of the early 1960's. This was a four-cam 356 mated to a lightweight Italian alloy body designed by Zagalo and built under contract for Porsche through Austrian expatriate Carlo Arbarth. These cars, about 20 in all, were not only used by Porsche's customers, but by the factory itself in both international and national events, including Le Mans where it won its class multiple times.

In 1965, the factory switched its concentration on the four-cylinder 356, to the just introduced six-cylinder 911, debuting the new coupe at that year's Monte Carlo Rally with a top five finish. Although the 911 would go on to make a name for itself in rallying - including winning at Monte Carlo on multiple occasions, and although it would do well in road course action also, development of the 911 as a race car was largely ignored by the factory until the 1970's

Even so, in private hands the 911 did well throughout the world, winning its class at Le mans as well as in the prestigious North American Trans-Am championship, and in the International Motor Sports Association's Camel GT. In 1967, Piech's engineers put together the 911R, the only attempt producing a lightweight 911, as a technical exercise. Never built in enough numbers (again there were between 20 and 25 made), the 911R, which featured a stripped interior and fiberglass fenders, doors and deck lids, was forced to run as a "prototype". Nevertheless, it created a legend of what "might have been" that would provide a foundation for later racing 911 models.

Late in 1969 the factory produced around 35 lightweight body shells. These would be used to build up both circuit racing and rally 911 through 1972. Although Porsche never gave these light weights their own designation, referring to them only as "911S's", unofficially they were dubbed "911 ST's". In their final, 1972 form, they were raced with 2.5-liter flat sixes, which used many parts from the Carrera 906 program. Perhaps, more important than their record was the fact that they served as a foundation for what came next, the Carrera RSR.

Developed under famed Porsche engineer Norbert Singer in 1972, after Piech had left the family firm, the Carrera RSR was the first true effort at creating a production 911 that could dominate the arena. Although it was lighter in weight than previous 911's, it did not go to the extreme that the 911A did, still it featured a number of fiberglass panels including bumpers and deck lids. In fact, two of the distinguishing features of the Carrera RSR when it was introduced in 1973 its ducktail rear spoiler and front bumper spoiler configuration, the latter unit having a center mounted oil cooler. In 1974, the Carrera RSR was revised slightly with a rear "whale tail" spoiler and new front bumper arrangement. The latter because of U.S. mandated changes in bumper regulations for the street beginning that year.

In terms of its fuel injected engine, the Carrera RSR was fairly standard stuff, not differing much from what had come before except for an increase in displacement. Originally raced in 2.7-liter form, its engine size rose first to 3.8 liters and then to 3.0 Liters. Regardless, the Carrera RSR dominated the production car scene from 1973 through 1975, wining the Daytona 24 Hours three times outright before ending its career in 1977. Additionally it won both the IMSA Camel GT and European FIA GT championships during that period, as well as a host of individual race triumphs, including the Targa Florio in 1973.

That latter victory came with a specially modified RSR run by the factory in Martini colors as a prototype. The following year Singer took things a step further, producing a turbocharged RSR with revised aerodynamics that included a raised rear roof and a huge rear wing. With this car, also backed by Martini, Porsche finished second at Le Mans, the highest placing ever for an RSR. The reason for the coupe's existence was the upcoming so-called "silhouette" prototype Formula that would be instituted in 1975 for the World Makes Championship,

Porsche planned to enter that series, with the much-modified 911-based 935, producing a less radical version for its customers called the 934. To gain experience the Turbo RSR was built as a "proof of concept" prototype. How well that worked can be seen In the fact that the 935 dominated the scene, winning the Manufacturers chase from 1976 through 1979, and the IMSA Camel GT up through 1972. During that same period both the 934 and the 946 won the Trans-Am crown as well as the German National championship and numerous other region series. Perhaps the high point of the 935's career came in 1979 when it won Le Mans outright, the first production-based car to do in more than two decades.

For all of its accomplishments, what the 935 will be most remembered for was its appearance. Planned to emulate the shape of the road-going 930, the appearance quickly changed when Singer found a loophole that allowed him to place the headlights in the bump, thus creating the first "slope" nose, which improved front-end downforce. Before the 935 exited the scene in 1984, it had acquired fully covered doors, a raised roar roof, sophisticated rear aerodynamics, and underneath its skin, a full tubeframe chassis structure

Moreover, what the factory had produced inspired Porsche entrants to create their own 935's using the drivetrain as well as suspension and brake parts from Zuffenhausen as their foundations. And, if the 935 was dominant, so too was the 934, which won Sebring in 1963, on its way to the Camel GTO title that season. All in all, the 935's and 934's represented the fastest and wildest 911's ever made.

But, they weren't the only modern production Porsche race entries. In 1970, Porsche introduced the competition version of its mid-engine, 914/6 roadster, the 914/6GT that won its class at Le Mans. The next year in the hands of Peter Gregg and Hurley Haywood, it would claim the inaugural Camel GT championship, going on to later win several Camel GTU crowns as well. The model was also active in SCCA National competition, and in international rallying, although it never achieved the success in either venue that it did in professional, high-end international circuit competition.

In 1979, the 914's successor, the 924 was introduced into racing, running initially in North America with the SCCA, where in 1980 it won the first of several National crowns. Also that year, a turbocharged version was run at Le Mans with some success. Subsequently, turbo 924 GTR's would win in the Trans-Am and IMSA, claiming, as did the 914, multiple GTU class title for itself. Also raced with some success, was the 944 Turbo GTR, which at one point was Porsche's mainstay entry in the Trans-Am. However, a lack of development of the latter car wound up severely stunting its career.

More recently Porsche produced the turbocharged, 993-based 911 GT2 eacer~m which cleaned house on the international production scene during the mid-1990's, and latter, was nearly unbeaten in the IMSA Exxon Series production arena. In 1998, Porsche introduced the GT class 911 GT2R at Le Mans where this 996-based coupe promptly won its class. In 2000, the 911 GT3R was unstoppable winning wherever it raced, claiming both the American Le Mans Series and Grand American Racing Series GT category crowns. For 2001 Porsche has introduced an improved version, the 911 GT3RS which is expected to continue what its predecessor has started.

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