Seppi's bright idea

When Jo Siffert convinced Porsche to take on Can-Am, this day-glo beast was the result. Cue a new lease of life for the great 917
By Gordon Cruickshank

It can be annoying when somebody muscles in on your patch. Suppose you were, say, a large wealthy country and had set up a race series between you and your neighbour which was going well and providing terrific racing, even if it was a pair of Kiwis who kept winning in cars built in England. But at least they were using home-grown engines. And then some German outfit rolls up and starts soaking up the prize money… This is the tale of how an angry red fireball of a car blazed a trail through Can-Am that would finally burn up the series.

Although Porsche came to dominate Can-Am until in 1974 spiralling costs and an oil crisis snuffed it out, the US-Canadian series was not on the Porsche ‘to win’ list until Jo ‘Seppi’ Siffert, tempted by the big money prizes, persuaded the Porsche and VW importers to lean on the factory, citing major sales benefits for the linked marques. As one of Porsche’s star drivers, who at Daytona and Sebring in ’68 had brought the firm its first major outright sports car victories, the Swiss driver carried considerable weight, and knew American tracks, teams and traditions.

At first a distracting side-order to the 917’s main course, Le Mans and the FIA championship, the first Can-Am car, a cut-down spyder, didn’t reach America until mid-1969, and against simple Chevrolet V8s bulging with torque the flat-12’s 580bhp didn’t go far enough. But the stubby 917PA did yield lessons that helped shape the Can-Am car that 1971 would bring.

Why did Porsche then turn its sights across the Atlantic? It wasn’t just thanks to Seppi’s persuasive powers; there were larger reasons. First, the ambitious firm had finally ticked the biggest box with victory for the 917 at Le Mans in 1970. Second, it was clear that the five-litre sports cars would be outlawed for 1972, at least for the all-important manufacturers’ title. The glorious 917, so expensively developed and assembled in numbers that outwitted FIA regulations, was about to be handed its gold watch and pension, and Porsche was not minded to start again with an all-new three-litre to fit the new regulations. Can-Am, though, ran to the more extreme Group 7 rules with no size limits, and could plant the Porsche banner in potentially huge US markets. California here we come – and Ohio, and Wisconsin, and Edmonton…

Porsche set to work assembling a pair of chunky 917 spyders with chisel noses, closely cowled cockpit and cutaway tail. One of these, 001, would stay in Germany for development; 002, our subject for today, was destined for Siffert and the US-Canadian challenge. Not that Siffert was chasing it at first. Willi Kauhsen, then Porsche’s test driver, laughs about it now: “Seppi said the PA was fast enough, but I made him come to Weissach and try the 917/10. After a few laps he said ‘Holy shit! I need this car now!’”

But where the fabulous air-cooled flat-12 had been the envy of European grids, it would struggle in the US. Beside Chevrolet’s beefy quarterback of a V8 it was a fly-half, a well-bred sportsman from a very different ballgame. Experiments with a flat-16 had previously offered marginal benefits, whereas turbocharging the 12 looked promising but needed time to develop, so for 1971 Siffert, running his own team with factory support, would have to make the best of an unblown 5-litre (up 500cc from the original) with every tweak Zuffenhausen could contrive. It propelled a square-edged wedge reminiscent of the compact 908/03 bergspyder but widened to fit larger tyres and fuel tanks ready for the even thirstier turbo, and flying a perky pair of fins aimed at stopping air falling off the rear deck and throwing away downforce. Usefully, Porsche had something of a warm-up: the Interserie championship also ran to Gp7 regs and the first rounds came before Can-Am’s summer start, so privateers such as eventual winner Leo Kinnunen could bring feedback on their open-topped machines.

With its alloy tubing braced by aluminium sheet the new Can-Am spyder was stiffer and lighter than the coupé, and arrived at Watkins Glen with a 630bhp sprint engine and some magnesium alloy components to stretch that power-weight ratio. Before the race its stark white turned into the eye-poking dayglo red of sponsor STP; it might be giving away 80-100 horses to the mango-coloured McLarens, but at least it could visually outshine them. In the event the swift Swiss took the new machine to a promising third. They’d already missed three rounds so the title was not in the frame, but with Porsche’s famed reliability at their backs Siffert and his small team might just shoot a few holes through McLaren’s results sheet. Two successive second places at Mid-Ohio and Elkhart Lake boosted Siffert’s hopes, but even the 30 extra horsepower of an enlarged 5.4-litre engine was trampled on by Chevy’s latest 740bhp 8.3-litre lump. The power gap stayed the same, but the results gap widened to fifths and fourths when Jackie Stewart’s Lola and, annoyingly, outsider Ferrari pushed past Siffert. For a tiny non-works team running a brand-new car the results weren’t bad, and nor was the income – but ‘not bad’ has never been the Porsche way. At the new Weissach engineering centre, complete with its own test track, Willi Kauhsen was honing the turbo development car, now with 200 more horsepower.

“Very exciting!” he recalls. “But not hard to handle – this car was built for the turbo. So Seppi decided he would buy a new turbo car, and I would have the old one.”

But, before the final Can-Am round of ’71, Jo Siffert died at the wheel of a Formula 1 BRM at Brands Hatch.

It was a terrible blow, but Porsche’s engineering dial was now at peak revs on Can-Am, and it is well-trodden history that, managed and entered by Roger Penske, Mark Donohue and then George Follmer grabbed six victories and the 1972 Can-Am title with the 900bhp 917/10K. After that the 917/30’s 1500 turbo horses fairly steam-rollered the series, until Can-Am was boosted into touch – partly by the expense of chasing Porsche’s success.


Siffert’s car, meanwhile, went back to Weissach where it was modified for Kauhsen to race in Interserie. Even Seppi’s partial season had placed him a posthumous fourth in the Can-Am standings, so it promised a lot against more standard 917s running in the Euro series. Curly-headed and goatee’d Kauhsen was a prolific sports car racer, particularly in Porsches, and would later form his own Formula 1 team. In 1970 he came second with Gerard Larrousse at Le Mans in the psychedelic Martini 917L, so while not quite a factory driver, he was a respected figure. So much so that to look after the new car, Kauhsen‘s Bosch-sponsored outfit was able to lease a factory mechanic. Now head of Porsche’s Rolling Museum and keeping the jewels of the company’s history in operation, Klaus Bischof remembers taking on the car.

“It did not really start as a 917/10, it was a 917 spyder Siffert had built up,” he says. “It did not have the big wing of the later factory cars. But we slowly turned it into a 917/10. Slowly because this was a small-money team.”

That big wing was now a vital fit in Can-Am, but it took the Penske team to persuade Weissach engineers that the downforce it produced was crucial, Porsche being used to thinking low-drag before everything. It was matched by a new concave nose with oil-cooler box, which quickly appeared on 002. As a new run of longer, wider and lighter 917/10s took shape ahead of Penske’s 1972 US effort, Kauhsen had learned how to handle the turbo’s all-or-nothing attitude and knew the power was worth the price. But even he couldn’t just whistle one up.

“There was a capacity problem at the factory,” says Bischof. “They could only build a few turbo engines, so at first they were only for Penske.” Nevertheless, in March Kauhsen took 002 to second at the Nürburgring, and a month later won at Imola. For the Silverstone round he obtained the 5.4-litre engine and qualified fastest, but a tyre blew him off the results. By now turbo power was available to customers, and Kauhsen had the 850bhp unit installed in 002.

“It worked well,” says Bischof, “only it needed more servicing. No problems with it, it even ran with our standard cooling.”

Kauhsen enjoyed it too. “It was fun, fun, fun – I was driving this car Monday to Friday for work, so a Sunday race was just another day!”

Kauhsen made the podium seven times, battling fast Finn Leo Kinnunen in his similar car right through ’72. Finally the Finn triumphed with Willi runner-up following a little adventure during practice back at the ’Ring. “A tyre exploded,” recalls Bischof “and tore the tank.” Kauhsen flailed off the track, heavily damaging the car which burst into flames. But he quickly recovered from his burns and finished the season in 001, a car he knew intimately.

For ’73 Kauhsen’s team built up a fresh 917/10, but with Kinnunen’s pace and later Vic Elford’s arrival with the even more gutsy 917/30 that was also sweeping the field clear in Can-Am, Kauhsen was fated not to become Interserie champion. Meanwhile the Siffert car stayed in the workshop. It sat there, just another old racing car, for 26 years. “After my F1 team I was completely out of money,” grins Kauhsen, as jovial now as ever. Finally, in 1998, when old racing cars had become rather more interesting and Willi had built a new business, it was pulled out for restoration.

The simple passage of time as well as the impact of accident and fire meant that all of it was suspect to some degree, and in the end a new frame was needed, overseen at Porsche by the same man who was in charge of production in 1971. Corroded hub carriers and suspension units also had to be replaced, with parts made at Porsche to original patterns or copied from the museum’s 917/10, and the same applied to the body, reproducing the form in which 002 first hit American shores. It’s a case of continuing identity more than original parts, but it means that with its unblown 5-litre and reliable four-speed ’box 002 is once again a raceable car, which Kauhsen has demonstrated at his favourite Nürburgring. If a prospective new owner decides it needs exercise, with that livery other drivers will have no excuse for missing it in their mirrors.