After a dominant 1-2-3 result at Le Mans in 1982, it was clear that Porsche's 956 was the car to have if you wanted to win in Group C. For 1983, a select handful of privateer teams took delivery of what was to become by far the most successful sportscar in history. Paul Fearnley braves the dark to discover what made the 956 great
The power (although there is more than enough to impress) is not the thing, it's the delivery, the Jekyll-Hyde transformation that shocks. Just minutes earlier we had been edging through the dimly lit streets of a quiet German town, being as incognito as you can be in a 650bhp Le Mans sports-racer.
Now, though, along the banks of the River Neckar, my Group C instructor flicks the mixture switch to espresso, winds the boost adjuster to full roast — and plants it. Which is when I smell the coffee. Twenty-four hours of this, through the night and on into the rising sun, passing slower cars as Win some madcap computer game: maximum respect Messrs Ickx, Bell, Ludwig etc.
Mind you, Jacky, Derek, Klaus etc never had to wedge themselves into a 956's non-existent passenger compartment. I'm perched on a couple of fire extinguishers, aged bolster cushion and travel rug offering scant protection to my kidneys (being cooked by four fuel pumps) and head (which nuts the Bosch Motronic 'black box' upon each acceleration). A road-type seat belt offers some support, but it takes most of my strength not to slump onto the driver's chest or slip ragdoll-like under the dash.
A burst of 1.4 bar qualifying boost, which stampedes in at 5000rpm, sees us rush up behind a line of poor unsuspecting Joachim Soaps. Firm brake. Down one. All clear. And whoosh! Can't begin to imagine what they must have thought. I knew what was coming yet could only manage a (very loud) expletive.
Had we bothered to stop and explain, however, I could have shown them: 'Look, it starts on the key. And here's the indicator stalk. It's even got hazard warning lights.' Yes, your average 956 has got most of the things we are accustomed to here on Earth. Which is of some comfort as I squeeze into the pilot seat of its command module.
There are other comforts: we are at Hockenheim now; we are on the short circuit (just second and third required with this gearing); and we have it all to ourselves — bar a road sweeper or two.
We had been scheduled to go out during the day, but the Porsche Club Rheinhessen was too busy re-enacting Death Race 2000 to risk it. Plus the old through-the-trees section of the GP track is being Bernie-fled, and the resultant construction traffic has transformed the Stadium Section into a rock-strewn forest stage. Neither the time nor place to make your Group C debut. But now, as dusk aptly gathers, I am as ready as I will ever be.
I'm faced by a Jumbo wall of flourescent orange-needled whiteon-black instruments, all of which have been explained to me in detail by the car's owner, Siggi Brunn, a man of vast Porsche racing experience, of encyclopaedic Porsche knowledge, and a Croesus-like hoard of Porsche spares. For him, it's another test; for me, it's another opportunity to avoid making a fool of myself. I rationalise: rev-counter, check; boost gauge, check; oil pressure warning light, check. That'll do.
With the seat slid as far forward as it will go so that my stumpy legs can dip the not-too-heavy clutch, and press the not-tooheavy brake, the steering wheel with its flat underside threatens to rabbit punch my solar plexus. But I had been warned that this is a physical car, so a bit of pre-emptive bicep curl might be no bad thing.
My first glimpse of this particular 956 had been with its underbody and tail section removed in readiness for a systems check on Siggi's new rolling road. Chassis 108, one of 29 built, one of the first batch of customer cars, appeared huge, complex and daunting — perceptions that did not dissipate any when its 2.65litre flat-six was triggered in this enclosed space.
As the twin KKK turbos spooled and dumped while Siggi went up and down the five-speed all-synchro gearbox, it sounded like the biggest of Big Rigs. If the murderously intent trucker from Duel had been so equipped, Spielberg's first great movie would have been a five-minute short.
My disquiet heightened when I took over the controls while still on the rolling road and discovered a throttle pedal that required a panic-brake shove to crack open. The thought of imprecisely summoning up a huge dollop of extra bhp at precisely the wrong moment led to a fitful night.
But now, the up-and-forward door clicked shut, my fate sealed, my mood lifts. Chassis 108 suddenly seems manageable, understandable. I know, I know, I haven't even fired the thing up yet, but that's how it feels. It has somehow shrink-wrapped itself around me. Some might find the cockpit claustrophobic; I find it strangely nurturing, womb-like. Odd. But there you go.
With my right hand I twist the red battery switch through 90 degrees, down and towards me, and with my left hand reach over for the key. Click. The fuel pumps whirr and prime. Then slow. I squeeze the throttle. And squeeze some more. And some more. Bloody hell! Might as well. Here goes. One final click. Spool and dump. Spool and dump.
First is back and across on a dogleg, but can only be accessed by slotting the lever into second and then pulling back through immediately. No problem. The throttle, though, still is. I stall.
Same procedure. Only this time I let the clutch bite at tickover. Chassis 108 pecks and shunts a bit, but she pulls away nevertheless. As I am to discover, this is an amazingly tractable racing legend. It was designed and built primarily to win Le Mans, which, in a variety of guises, it did on seven occasions (five of them consecutive 1-2-3s) between 1982 and '94. But it doesn't stop there. Oh no.
During the period 1982-86, 956s won 71 races, including 26 world championship encounters. Its 962 cousin, featuring a longer wheelbase to bring the driver's feet behind the axle line, two-valve-head 935 engine and single turbocharger, won 51 IMSA races between June '84 and '89, while the GpC version won 14 world championship events during '85-89, and added three more IMSA victories to the total. The flat-bottomed GT 962 won on its only outing, the 1994 Le Mans 24 Hours.
Porsche, under the auspices of Peter Falk and Norbert Singer, got to grips with the demands of this new form of racing much faster than any of its rivals and scored crushing early success. Of the 40 top-10 Le Mans placings up for grabs between 1983 and '86,956 and 962 secured 32 of them.
Even when more modem offerings from Jaguar and Sauber began to outpace the old girl, she stayed competitive much longer than she ought, especially in the longer-distance stuff: in 198687, Derek Bell and the late Al Holbert, Porsche's number one man in America, won four 24-hour races (two Daytonas and two Le Mans) on the bounce. In total, 962 won five Daytona 24 Hours (1985-87, '89 and '91) and four Sebring 12 Hours (1985-88).
So a few slow tours behind a camera car, chuntering around in second, should provide no difficulty. It doesn't. And once released, I am allowed a dozen or so laps, a privileged, fleeting glimpse into what those stunning statistics encompass.
The first thing that strikes me is the user-friendliness of it all — even the throttle, once it has been snapped just beyond open. The choice of a synchro 'box seems unusual on paper, and its change is not the fastest, requiring a fractional pause in neutral, but it's a doddle and oozes solid reliability. At the other end of the ratio scale, Porsche developed the semi-auto double-clutch PDK gearbox, but whenever Le Mans loomed, there was no question which unit the drivers wanted bolted in the tail.
The next thing I notice is that there is neither an in-cockpit brake balance bar, nor anti-roll bar adjuster. The implication of these omissions? We design, you drive. In the pilots' defence, they had plenty of other things to think about.
More than anything, Group C was a fuel economy formula: its original 600-litre limit for a 10001km race requiring an mpg of 4.7 if you wanted to see the chequered flag. In response to this, Bosch developed its groundbreaking Motronic 1.2 ignition system for racing purposes. This black box replaced its mechanical injection on the works cars in 1983, and on the customer cars the following year. Its more accurate monitoring of fuel demand and subsequent flow increased efficiency and allowed a substantial hike over the original compression (from 7.2:1 to 9.5:1) on the pump fuel demanded by the regulations. Such were the advances in this technology, when the allowance was slashed by 15 per cent to 510 litres in 1985, the cars went faster than ever.
The nub of all this, for the driver at least, is a 13-position rotary switch in the middle of the dashboard: away from you and tdc to weaken, towards you from tdc to richen. With this, a driver walked a tightrope between mpg and mph. The meaty metallic turbo boost adjuster must have been a great temptation, but the situation would have to be drastic for it to be cranked up during a race. Balls-out qualifying, of course, was a different matter. Me? I have one bar of boost, which is sufficient, thank you very much.
Peering through a goldfish bowl of a windscreen, massive sun reflector occluding the view past the A-post through the track's nadgery new chicane, I navigate a careful course. Muck and stones hoovered up by the slot under the nose rattle disconcertingly against the floorpan. I was never going to feel the gravitas of the two cavernous ground-effect venturis or the high-downforce shorttail sprint rear wing on this track (aero grip usurps mechanical at about 140mph), but the conditions dictate an even more cautious approach than originally planned.
So here I sit, feet slightly higher than backside (the underbody forms a negative-pressure aerofoil shape just behind the nose), musing about what Vem Schuppan must have thought when he first climbed aboard 108 in 1983. The tall blond South Australian from Booleroo and co-driver Jochen Mass had been the 956 filling in a 956 sandwich at Le Mans in 1982. He won the world's greatest sportscar race in '83, alongside Holbert and Hurley Haywood, but spent the bulk of the year concentrating on Japan's Group C series, sharing this Trust-sponsored, Nova-run car with Naohiro Fujita. They won on four occasions that season, and secured the JSPC and Fuji titles in the process.
Schuppan was joined in 108 by Yoshimi Katayama for 1984, and they won first time out in the Suzuka 500I(m.
Then disaster. A testing shunt at Fuji ripped a comer off. The damage was repairable, but time was short and so chassis 118, the last registered 956, was shipped out, and 108's mechanicals were swapped over into the new tub. And 108's tub lay untouched at Porsche until 1988, which is when Siggi purchased it and a bundle of spare, and began the rebuild.
Driven by him and 24-year-old son Philip, 108 is regularly the fastest of the 956s and 962s in the burgeoning Group C Revival races. Which is where its development continues: Moton shock absorbers have replaced the original Bilsteins, while a modem on-board data-logger unlocks what few small secrets remain on this tried-and-tested 19-year-old chassis.
It's more fundamental for yours truly. The brake pedal has a longer travel than I'd expected, although the dinner plate-sized vented discs and twin calipers shed speed just as I had imagine they would. The steering, less than a turn from lock to lock, has an inclination to drop onto full lock in the twisty stuff, while the lack of any noticeable self-centering demands that you steer out of as well as into corners.
I am sinking into a blissful reverie, soothed by 108's Dr Jekyll bedside manner. Time is running out, though. It's time to seek out Mr Hyde.
Exiting the left-hand sweeper onto the short back straight, I summon my courage and step into a different dimension. My head rocks back and my feet go zero g for an instant. I keep it in and punch it through into third. My God, it's doing it again. And to think they sometimes used 3.2-litre motors in qualifying. And to think the Mulsanne is three miles long.
Next time around, feeling cocky, I try it again, but the motor coughs and splutters. Despite blanking off all the hip-mounted water and oil radiators, and the water/air intercoolers, the plunging ambient temperature is causing the engine to misfire. Of course, had I been Ickx, Bell or Ludwig, I might have thought to richen the mixture. But I'm not. So I didn't.
I pull in and Siggi, bless him, wants to know this and that and the other. I really can't help him. For I have just been to the other side, for the first time, and it's all I can do to navigate our Opel Astra hire car through the deserted paddock and along a quiet stretch of autobahn. The Mulsanne at night — even if the car is as capable, as reliable, as trustworthy as 956— is the domain of a different breed.
Definitely one of the darker arts.
Technical specification - 1983 Porsche 956
Chassis: sheet aluminium monocoque with integral alloy roll-cage
Type: flat-six, dohc, twin turbo, four-valve water-cooled heads, air-cooled Nikasil barrels
Bore and stroke: 92.3 x 66mm
Comp ratio: 7.2:1 (on 98-octane pump fuel)
Firing order: 1-6-2-4-3-5
Max revs: 8500rpm
Max power: 630bph @ 8200rpm
Max torque: 465lb/ft @ 8400rpm
Specific output: 238bhp/litre
Crankcase: 2-piece casting
Crankshaft: forged steel
Conrods: forged titanium
Pistons: forged aluminium
Turbochargers: KKK, K26-360
Turbo boost: 1.2 bar @ 8200rpm
Fuel injection: Bosch, mechanical
Ignition system: Bosch
Spark plugs: Bosch
Gearbox: Porsche, 5-speed manual, synchromesh
Clutch: Porsche, single dry-plate
Final drive(options): 4.6:1 (4:1 or 4.2:1)
Front suspension: double wishbone, outboard spring/damper
Rear suspension: lower wishbone, upper rocker arm, inboard
Shock absorbers: Bilstein, gas
Brakes (f & r): Porsche, twin calipers
Discs (f & r): vented, 330x30mm
Steering (ratio): rack-and-pinion (11:1)
Wheels (f/r): BBS, 12 x 16/15 x 16
Tyres (f/r): Dunlop, 600/280 x 16, 650/350 x 16
Tank capacity: 99.5 litres
Bodywork: 7-piece Kevlar/fibreglass/aluminium
Track (f/r): 1648/1548
Dry weight: 840kg