Porsche 959
For a car that has yet to be driven by a customer, the Porsche 959 has generated an inordinate amount of publicity. It first appeared at the 1981 Frankfurt Show as a “Studie”, then at the 1983 Frankfurt Show as the “Gruppe B” virtually in definitive form. In January 1984 a comparatively primitive form of all-wheel drive was fitted to the Paris-Dakar winning 911, and in January 1986 the much more sophisticated, electronically controlled 4-wd system was used in the cars that finished first, second and sixth in the fated Paris-Dakar event.
Two hundred customers have long since parted with their DM 50,000 deposits and, in September, the first of them will take delivery of their DM 420,000 engineering marvels, the UK tax-paid price working out at around £140,000! What will they get . . . and was it worth waiting for?
The heart of the Porsche factory is not the production line, as in most motor companies, but the research and development centre at Weissach where 2,500 engineers are engaged on a great number of projects both for Porsche and for outside client companies. It has always been a tradition that the engineers “sign off” new developments only when they are completely satisfied with them, then handing the product over to the marketing department. Since his appointment in 1981 chief executive Peter Schutz has certainly given sales and marketing a greater role in decision making, hence the policy of producing the 959 model with an engine capable of running on lead-free fuel, and capable of ultra high performance with catalytic equipment installed (this policy, in fact, adding at least a year to the development time). It may be that the 959 is the last, in the foreseeable future, to be an engineering showcase, crammed full of goodies that will permeate the range in years to come.
Certainly the need to stop development, at some point, and actually produce the cars — the number has now been increased to 250, incidentally, including lightweight “Sport” versions — has become something of a nightmare. The systems are so numerous, and so complex, that Professor Helmuth Bott may never be entirely satisfied, but whereas Ferrari for instance would have cloaked such a car with tight secrecy, and announced it when he was good and ready, all of Porsche’s advanced engineering has been high profile, open and above-board.
Basically the 959 is a wondrous development of the 911 Turbo, no doubt about that. The steel monocoque cabin is a familiar shape but the front and rear chassis sections are completely new, and the entire car is clothed in aerodynamic bodywork consisting of aluminium (the front hood, and the doors), impact resistant polyurethane (front apron) and various Aramid and Kevlar lightweight composites for the main cladding including the front wings, the flared rear arches, the engine cover and stylised rear aerodynamic wing, even the undertray. By these means the drag coefficient has been reduced from the 911’s 0.385 to a new figure of 0.31, a remarkable figure when you consider that the 959 has zero lift at high speed.
The engine is supremely powerful, and is a close relative of the type 956 racing engine that has won four consecutive World Endurance Championships. The capacity is raised to 2,850 cc, so that FISA’s equivalency of 1.4 brings it within the 4-litre class, and the three cylinder heads on each bank are made as one casting, more in conventional style than by Porsche’s traditional method of making individual castings. The reason, of course, is that water cooling is employed for the four-valve heads, though air and oil continue to cool the barrels. Below the twin, Duplex chain driven camshafts on each bank are hydraulic shims to ensure correct, maintenance free adjustment, though expensive features include titanium con-rods, the sophisticated Bosch Motronic engine management system straight from the Group C cars, and an array of radiators: one for water, two for oil cooling, and two air / air intercoolers, mostly mounted at the rear. The most obvious difference between the 959 and its “Gruppe B” showpiece is the removal of the rear ducting to the forward edges of the flared rear arches, instead of having NACA ducts which Prof Bott freely admits didn’t work properly. Also of course, prominent straked grilles appear in the bodywork on all four corners for brake cooling and air extraction, other necessities not necessarily attended to in a show car!
The engine develops 450 horsepower at 6,500 rpm and a torque value of 500 Nm (369 lb ft) at 5,500 rpm, aided by twin, progressively programmed water-cooled turbochargers. The smaller of the two provides an effective amount of boost from as little as 2,000 rpm, and the large one chimes in with an impressive surge at around 4,700 rpm, its arrival being a very marked characteristic of the car’s performance. The rev-limiter is set at 7,800 rpm which equates with 60 kph (37 mph) in first, 105 kph (65 mph) in second, 150 kph (93 mph) in third, 205 kph (127 mph) in fourth, 260 kph (161 mph) in fifth … and a theoretical 320 kph (198.8 mph) in sixth! Did we forget to mention the brand-new six-speed gearbox?
At the Le Mans trials on May 9 Porsche was due to have tested the 961, the competitions version of the 959 intended for IMSA racing in the States next year. The weight has been reduced to 1,100 kg compared with the luxury model’s 1,450 kg, and less even than the 959 Sport model’s 1,350 kg achieved by deletion of the air conditioning system, some of the soundproofing, the rear seats. the passenger door mirror (1), and by fitting sport seats at the front. Out, too, will go the sophisticated computer controlled ride height adjustment: the brakes will be from the type 962C racing car, but are feared to be rather lightweight for stopping this 230 mph car at Mulsanne Corner. The engine will be the standard 2.85-litres, rather than the 962’s 2.65-litres, but will have the normal pair of KKK racing turbochargers.
The racing version will. though, have the advanced Clayton Dewandre anti-skid brake system, which will also be tested on the works Porsche 962C in the German sprint races this year. Unlike other systems, such as Bosch and Teves, the Wabco Westinghouse system is actuated by micro-chip sensors adjacent to all four wheels, and linked to the electronic 4-wd system. The Wabco set-up is also gravity-conscious and able, therefore, to function even when the 4-wd system is in the Traction mode (that is, with the centre clutch fully locked) and, importantly, there is no pulsing feed-back through the pedal.
The “chips” are set for say 3g stops on the racing car or 1g stops in the road car — so what happens if it rains? The system automatically adjusts downwards according to the adhesion available at the first application. It all sounds terribly complicated, like the four-wheel drive system itself, and it undoubtedly is, and therfore it is massively expensive. But, so long as the driver needs not bother himself with these systems in everyday use, and so long as they remain totally reliable, there need be no concern about them. The 959, by the way, carries a 10-year corrosion guarantee, the usual one-year mechanical warranty (though service problems will be treated “very sympathetically” by importers representing the factory) and service intervals are at no less than 20,000 kilometres.
Around the ‘Ring
It has to be admitted that there are two quite separate sets of impressions of driving the Porsche 959 around the new Nurburgring: those of a journalist driving this 450 bhp projectile around a strange circuit, in awe and trepidation and those of riding passenger with chief test driver Gunther Steckkonig! Guests from various countries included Giancarlo Baghetti from Italy, Henri Pescarolo and Jose Rosinski from France and Paul Frere from Belgium, along with John “Lotus” Miles and Tony Dron from England, so there was never a remote chance of setting impressive lap times.
Even someone familiar with the normal Porsche 911 Turbo, and 300 bhp. has a lot to learn before this first (and, we were assured, only) driving experience. The 4-wd system is, basically, a multi-plate oil bath clutch located between the front and rear axles. It is constantly turning slowly, since the rolling radius of the front tyres is slightly greater than that of rear tyres, and in a variety of conditions the plates are partially or completely clamped-up, quite automatically, to vary the front rear drive split almost infinitely. Then, while it is capable of altering the clutch pressure in 50 to 100 milliseconds, the driver also has the option of four override modes selected by a column lever: the first is Traction, fully locking the clutch for climbing out of sand or snow drifts; the second is for icy conditions, the third is for wet roads and the fourth is for dry roads, progressively reducing the clutch plate hydraulic clamping pressure. The system will also compensate for weight transfer under hard acceleration, and is sensitive to incipient wheelspin.
Only in the very hardest cornering conditions, though, need the driver even be aware of this micro-chip marvel going on beneath his seat, and even on the sinuous German race track I, in the journalist mode, could not honestly evaluate the advantages of four-wheel drive. That the machine is blindingly fast can be assumed without question. That it goes around the corners sure-footedly is also a certainty, despite 60% of the static weight, say 870 kg, being on the back wheels, but only a back-to-back with a rear-driven 911 could truly reveal how much progress has been made, though we believe that it’s a good deal.
The brake system was super-impressive, especially at the end of the short pits straight where a speedometer reading of 210 kph was seen at the 300-metre board. The road ahead is a tight right-left chicane with high kerbs to punish the venturesome, and it was possible to stand on the brake pedal to kill speed. To turn in while still braking, as I have to admit doing on one occasion, would be absolutely suicidal in a 911 Turbo yet the 959 bore the indiscretion with contempt.
A race track is a stern test for any road car, no matter how competent, on highway suspension and tyres, and the rear suspension particularly could be felt to be working hard. The 959 was definitely rolling a little, settling into a mild oversteer that never developed, never gave cause for concern, and could be reduced by hard applications of the throttle midway through the turns. But I was driving it as a road car, feeding the throttle rather than flooring it.
Gunther Steckkonig, who’s reputed to be even quicker than Hans Stuck in this particular car, showed another approach, that of the racing driver. He would leave his braking until the 200 metre board, stamp on the brake pedal then throw the car bodily at the inside kerbing in a beautiful tail-out display of control. The transition from right to left was quite violent, but Steckkonig was a gear higher than I had used — fourth, rather than third —and was a full 30 kph quicker at the clipping points. Where I had been nervous of getting the 959 “out of shape”, as anyone who’s driven 911s tends to be, Steckkonig was revelling in full-blooded, tail-sliding drifts and probably lapping 10 sec quicker. Now, too, I could see that full throttle beyond the limits of adhesion does, indeed, induce fairly massive understeer which could only be contained by easing back momentarily from the throttle, and letting the back wheels dictate the shape of the curve. It’s hard to believe that this car would ever “bite” the owner at any speeds attainable on public roads, which may be the highest compliment that can be paid to it.
Of the engine, one wonders whether the progressive turbocharger system is quite as good as it’s supposed to be. One can even get blase about 450 bhp, given time, and it was noticeable that when fourth gear was taken the performance even felt a little flat for a few seconds, until the larger turbine got busy. Officially it’s calibrated to supplement the smaller turbocharger at 4,300 rpm, but acceleration levels off at that point, only to step off again with a mighty shove at 4,800 rpm. In the lower gears this happens terrible quickly, the standstill to 100 kph time for instance being a mere 4.3 sec, while another 100 kph is added in a further 10.5 sec. That the 959 will reach 125 mph in the time it takes a 911 Carrera to reach 100 mph is much more impressive than it sounds! The Porsche 959 is an enormously competent car which represents great investment, both in terms of engineering expertise and customer investment. Were all this lobe done for merely 250 customers it would. unquestionably, have been a folly of the grandest proportions, but of course that is not Porsche’s way. This is the pot pourri of technical exercises that will be applied to the range over the next 10 years. You may well imagine that the 6-speed gearbox would be a godsend to the 911 Turbo owner, who’d also like the progressive supercharger system. The water-cooled, four-valve cylinder heads will surely be seen on the 911 Carrera, the height-adjustable suspension on the 928S, the four-wheel drive system on the 911 Turbo, and so on. Nothing goes to waste at Weissach, where even the PDK racing transmission will soon find its way into the four and eight cylinder ranges. — M.L.C.