The History Of Porsche’s Most Successful Prototype: The 956/962
By Bill Oursler for 962group.com
When design and development work began on what was to become Porsche’s new Group C prototype, the 956, in the late spring and early summer of 1981, few realized that what was being created would be one of the greatest racing cars to ever carry Zuffenbausen’s banner in competition. Indeed, it was not until the program had been underway for several months that Porsche’s management gave its official blessing to the project, which heretofore had been little more than a speculative exercise.
During the latter half of the 1960’s when the factory’s motor sports fortunes had been the responsibility of the ambitious Ferdinand Piech, the nephew of company head Ferry Porsche, the company had produced a series of ever more potent prototypes, ending with the famed 12-cylinder 917, that had taken it from a sideshow class winner to the dominant center stage payer on the sports car scene. However, when Ferry Porsche, long with the rest of the family members, including Piech, left the day-to-day management of the company to others at the end of 1971, Zuffenhausen’s motor sport focus shifted to the production arena.
Just one traditional sports racing prototype, the open-topped 936 spyder, was produced after the 917 in the 1970’s and then only as a hedge against the Federation International de L’Automobile, the world governing body for the industry, changing its mind about basing its Manufactures Championship around its new production-car oriented Group 5 formula, introduced in 1976. Ironically one man is not happy with the decision of then Porsche president, Ernst Fuhrmann to go ahead with the 936 was Porsche’s chief race engineer, Norbert Singer, who would head the 956 program.
For Singer, the man behind the Group 5 935, and its less modified Group 4 cousin, the 94, the 936 was an unwanted diversion. “I know,” said Singer, I was not enthused about the decision to proceed the 936, but one doesn’t argue with one’s boss.” In fact, the 36 was raced on a full-time basis for just a single season in 1976 when it won both the FIA’s World Sports car title, as well as Le Mans. After that, its outings were limited to the Sarthe classic, which it won again in 1977, and for a third time in 1981, placing second in 1978 and 1980.
The 1977 victory, however was a lucky one, the winning car of Hurley HaywoodJurgen Barth and Jacky Ickx, finishing on five, instead of six cylinders after having burnt a piston in the affair’s finial hours. Happily, the turbocharged 936’s opposition, the boosted V-6 Renault Alpine 442’s all retired with similar problems. Still, Porsche engineer’s after reviewing matters, decided that the basic 911 turbo six had been pushed to its limits, and possibly beyond. As a result, the factory introduced a water-cooled head version of the power plant for 1978, this in turn serving as a foundation for the 2.6-liter unit Porsche developed for its aborted 1980 Indianapolis 500 effort.
In 1981, this engine was installed in the 936 at the orders of Porsche’s than new president, American Peter Schutz, for one last attempt at Le Mans. What made the ’81 Le Mans the swansonmg for the 936 was the fact that the FIA had changed course again as the ‘80’s approached and decided to return to a custom-built prototype formula for its headlining sports car tour starting in 1982. Even as the two factory 936’s were being prepared for the Sarthe, Singer, and Helmut Bott, head of Porsche’s motor sport program, along with Bott’s number two man, Peter Falk, were drawing up preliminary plans for Group C.
“We knew,” said Singer,” that we wanted to enter Group C, first as a factory, and then later with customer cars supporting our own efforts. What wasn’t certain was the kind of car we should have.” What was clear, though, was the engine it would employ, the 2.6-liter turbo six then being used in the 936. This was because the power plant could be easily adapted to the unique regulations for Group C which left engine design free, but which imposed a maximum fuel limitation instead as a means of controlling performance.
meet the rules, essentially the only changes which need to be made to the water-cToooled head Porsche was the substitution of motronic ignition for its original mechanical fuel injection system… Still, the ultra wide boxer six cylinder did create problems for Sinr, who wanted to incorporate a “ground effects” capability in the new car. “We had pretty much developed the topside,” recalled the Porsche engineer. “What we needed to do now was to improve the grip by working on the underside.”
That would not prove to be easy, especialy since Singer wanted to abandon Porsche’s traditional tube frame concept for a monocoque chassis. “Herr Bott, wasn’t in favor of doing it,’ Singer said. “However, after I told him, as well as Herr Falk that we needed to make a monocoue in order to meet the new FIA crashworthiness rules, they went along.” Even so, perfecting the ground effects package took some time. :”What we discovered in our wind tunnel tests, “ said Singer, “was that ground effects didn’t work the same way a full width sport car as it did in a single seat formula one car.”
What Singer learned in two weeks of testing was that unlike its open wheel counterpart, the sports car drew the air for its ground affects tunnels from between the front and rear wheels rather than from the nose. Thus, whenever skirts were added to the early 956 wind tunnel models, the ground effects disappeared. With that discovery, the shape of the tunnels became even more important, the solution tot his being helped by the decision to angle the engine slightly upwards to the rear.
What emerged eventually was a car that employed a simple, but effective monocoque at the front with a conventional doublewish bone suspension. Behind the monocoque, which ended at the rear cockpit buikhead was a detachable tubular sub frame which supported the engine, he transmission and the rear push-rod suspension, this being utilized to increase the effectiveness of the tunnels by placing the sprin-shoock units above the carefully crafted under tray.
Uniquely, the water radiators, intcoolers and turbo's were placed in the side pods just behind the cockpit doors that’s top-mounted “ramp design fed the air inlets for these units. Fitted with a completely removable enclosed body that mimicked the early 917 design in many ways, the 956 proved to be a winner almost from the moment it first saw competition in the spring of 1982. In fact, its sole “loss” that season came at the opening Silverstone round in May were it won Group C, but finished second overall to a Group 6 Lancia prototype spyder that had been “grand fathered” into the series from the previous era for that one year only.
After Silverstone, the 956 wasn’t to lose again, either in Group C, or overall, including among its triumphs, the 24 Hours Le Mans. In fact, 956’s would win the long distance classic and the season FIA series honors without a break until being replaced by the longer wheelbase 962. For the Sarthe that meant four straight triumphs, two coming via the factory, the first with Ickx and Bell in ’82, and the second the following June with Haywood, Vern Schuppan and Al Holbert; the remainder though the efforts of privateer Reinhold Joest whose 956, chassis number 117, became one of the very few “double” Le Mans winners in history, gaining back-to-back first place trophies in 1984 and 1985.
As for the World Sports Car title, that went to the factory, five straight times between 1982 and 1986, Zuffenhausen switching to the 963 form 198 on. The existence of the long wheelbase version of the 956 was not Porsche’s idea, but rather that of American John Bishop, the founder of the International Motor Sports Association and its impressive Camel GT Series. Bishop, who had been helped early by Porsche through its support of his fledgling championship had become tired of Zuffenhausen’s domination of the Camel Gt, first with the Carrera RSR, and later the 935.
When Porsche introduced the 956, Bishop refused to accept it for his North American-based tour, objecting to its water-cooled power plant as well as the fact that its driver’s feet were placed ahead of the front axle line. In the latter part of 1983, Porsche agreed to introduce a new version for the 956, one using the air-cooled 935 variant run in IMSA for years, as well as a wheelbase stretched at the front, which placed the driver’s feet behind the theoretical front axle line.
This was the 962, first race by the factory at the 1984 season opening Daytona 24 Hours where it retired with engine and gearbox problems in the hands of Mario and Michael Andretti. The appearance of the 962 as a factory entry upset Porsche’s North American contingent, which thought the car was to be theirs alone. In fact, the Andrettis were the only one’s ever to drive officially for Zuffenhausen in IMSA throughout the 962 era. Even so, when the first “customer” examples were delivered in the spring of 1984, success, despite Bishop’s worries, was not immediate, the air-cooled 2.8-liter engine proving to be inadequate to the task of being the Jags and their Chevrolet Martch counterparts, which would rule the series that season.
Not until the mid summer of 1984, when Golbert fitted a 3.2-liter mechanically injected turbo 935 six into his Lowenbrau Beer backed 962 did the model find its “sea legs.” (In actuality Holbert and bell had scored the model’s first ever IMSA triumph in June at Mid Ohio with the original motonic 2.8-liter, ironically the last time the Loenbrau team used the Porsche factory supplied unit.) The larger displacement six, plus the adaptation of the 956’s short tail (as opposed to the long tail used at Le Mans and the initial rear 962 body that appeared to be a cross between the two) transformed the 962 into a long-term winner.
Not until Bishop changed his regulations to restrict the 962’s performance did the Porsche falter as the leader of the pack providing Holbert with two Camel Driving titles ohis own (to go with his three prior Camel crowns) and Porsche with four straight Daytona triumphs between 1985 and 1987. Moreover, the venerable Singer design was also used by Holbert driver Chip Robinson to garner the ’87 Camel Drives championship, and by BFGoodrich trio Derek Bell, Bob Wollek and John Andretti to win the Daytona 24-Hour affair in 1980.
Even so, by the latter part of the 1980’s ages, as well as regulatory restraint, were eroding the Porsche’s competitive edge. In Europe the Tom Walkinshaw Jaguar V-12’s and the Sabuer Mercedes V-8 turbos had supplanted the 962, ending its reign both in the FIA tour as II as Le Mans. Indeed, ironically it was Holbert, along with Bell and Hans Stuck who would score the factory’s last “official” 962 triumph at he Sarthe, this coming in 1987 over the Walkinshaw Jags. After that it was the TWR folks, along with Mercedes who dominated TWR; ilreise pressing hard in North America where it won at Daytona in 1988.
Despite all the factors conspiring against it, the 962 weren’t quite ready to give up as the 1990’s approached. At the turn of the decade a Joest entered example surprised everyone by once more coming out on top at Daytona, this time with Haywood leading the way. In fact, the 962’s final IMSA triumph wouldn’t take place until the mid 1990’s, the model taking the 1993 IMSA Road America event, and then a thoroughly amazing win with a spyder bodied Kremer version at Daytona in 1995. That 24-Hour effort was part of a tale that went back to the previous June when two “sub rosa” factory 962’s appeared at LE Mans under the supposed direction of privateer Jochen Dauer.
Dauer, a German citizen had been working on a street version of the Porsche coupe when in the fall of 1993, Singer appeared on his doorstep with a proposition. What had brought Singer to Dauer was a quirk in the Le Mans rules, which allowed a racecar such as the 962, to be entered in the GT category as long as one street legal example had been made and registered. Suddenly Dauer was awash in Singer’s help, the required streetcar appearing in the spring of 1994 along with a pair of racing counterparts.
Entered at the Le Mans by Dauer, but crewed and controlled by the factory, the cars lived up to the pre-race billing, one winning handily in performance helped once more by Haywood’s efforts. A result of this stunning effort, Alvin Springer, the man heading Porsche’s North American racing program, arranged to purchase Tim Walkinshaw’s last Jaguar Group C coupe, having it transformed into an open-topped, non ground effects spyder with a 962 flat six transplanted into its engine bay.
Prepared for the 1995 Daytona affair, the car was sidelined by IMSA politics which had pre-selected Ferrari’s 333SP as its preferred winner. Unfortunately for IMSA and Ferrari, the 333SP’s present all retired with mechanical woes, leaving the way clear for the Kremer entered 962 spyder whose lap times were some eight seconds off those of the Ferrari brigade. It was the final twist in a long gale of Porsche dominance the extended back for the best part of a decade and half. Still, the ironies were quite over as in 1996, the TWR Porsche spyders were trotted out at Le Mans where one, under Joest’s banner one’ the same car and the same team punctuating the effort by winning for a second time in 1997.
Today the 956 and the 962 live on in historic racing, continuing to provide their owners and fans with the kind of excitement that so often has been missing from the contemporary sports car scene. Who knows, perhaps the 956 and 962 will still be winning years after those who conceived it and initially drove it are but dim memories.
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