PORSCHE 917, CHASSIS #006 AND #008 TESTING AT ZELTWEG (1969)
"The 917 Test Mystery Success has many fathers and failure few, and thus it was with the test in the autumn of 1969 that made Porsche's 917 a real racing car for the first time. Two new books bring enlightenment where confusion once reigned.
One of the most enigmatic episodes in Porsche history was a Type 917 test session at Austria's new 3.73-mile Österreichring circuit, near Zeltweg, in the autumn of 1969. It was of great significance in several respects. It marked the first time that Porsche's engineers co-operated with the Gulf-backed John Wyer team in any racing effort. And it followed a troubled debut season for the 4.5-litre flat-12 917 whose drivers dubbed it 'The Ulcer' for its frighteningly wayward behaviour.
One enigmatic aspect of the test was its timing. Here's what I said in my history of Porsche:
'The shape of the 1970-model 917 was significantly affected by a test session at the Österreichring in August 1969. The site was convenient for testing because both the Porsche and JW teams were there for the 1,000-kilometre race that ended the endurance-racing season on August 10th. Both remained at Zeltweg for three days after the race for a test session managed by John Wyer and fully supported by Ferdinand Piëch and the rest of Porsche's top technical staff.'
I based my timing of the session on the testimony of Paul Frère, who wrote about 'the test runs for which the track was hired after the race,' which was won by a 917 driven by Jo Siffert and Kurt Ahrens-the model's first victory. As well I found a quote from Brian Redman, who said that in the tests 'I drove the car that I'd been driving in the race the day before, and it did the same time as in the race, and felt just as bad.' These assertions placed the test in mid-August. They were wrong, so I was too. And in fact neither John Wyer nor Ferdinand Piëch was present for the tests.
Two new books make the timing crystal clear. One is Racing in the Rain by John Horsman and the other is Porsche 917-Archiv und Werkverzeichnis 1968-1975 by Walter Näher. The former was chief engineer for the JW-Gulf team and the latter was a Porsche experimental engineer who was given full access to the 917 archives. They agree on the date of the Österreichring test: 14 through 17 October 1969. The first day, Tuesday, involved Porsche alone. The John Wyer crew arrived on the 15th, led by Horsman and JW team manager David Yorke.
Two 917 coupes in Group 5 configuration were available for the test. One was 917 006, which had been used for training at Le Mans, and the other was 917 008, which had led at Le Mans before retiring in the 21st hour. Both had 1969's short-tail layout. Instead of the original suspension-actuated rear spoilers, since the August race in Austria the spoilers were fixed in place albeit adjustable in their angles.
Major background for the test was the 917's unpredictable instability. JW-Gulf's contracted tyre supplier Firestone was on hand but refused to take part at first. 'We inquired what was happening and why they were not our there testing their tyres,' wrote John Horsman. 'They replied that they did not want to get the blame for the poor handling of the 917 and were not going to put their tyres on the car until it was sorted.' That's how poor its reputation was.
'We were the guests,' Horsman continued, 'and Porsche ran the show.' Led by experienced Zuffenhausen engineers Peter Falk and Helmut Flegl, Porsche started testing on Dunlop tyres on the 14th with drivers Brian Redman and Kurt Ahrens. Suspension experiments continued into the 15th with no significant improvement in behaviour or lap times. While their target was 1:46.6, turned in the August race by a Gulf Mirage-Ford, the best they'd managed so far was 1:48.2.
'In the clear, still autumn air of the Austrian hills,' John Horsman observed, 'there were clouds of gnats flying around, and their remains were splattered all over the nose and windscreen of both closed 917s. I noted there were hardly any dead gnats on the rear spoilers, which by now had been raised into near-vertical positions during the course of testing with no discernible effect on the handling. Since they were very small and light, I knew the gnats would flow over the bodywork exactly as the air flowed. Any gnat remnants on the white paint would indicate the air had touched that surface. This proved to me the airflow was barely touching the rear spoilers.
'I knew immediately that we had to raise the rear deck,' Horsman continued, 'and then attach small adjustable spoilers to the trailing edge. It was obvious to me that if the whole rear body surface was in the airstream it would be able to exert some downforce. So, supported by David Yorke, I asked Peter Falk and Helmut Flegl if we could "borrow" 917 008, as it was standing idle at the time. Somewhat puzzled, but wanting to be co-operative with the "Englanders", they said "Ja". And do you have any aluminium sheet in the trucks? "Ja." And could we borrow some snips, and pop rivets, and duct tape? "Ja."'
Now we've arrived at another enigmatic aspect of this test. Porsche's perspective on these events on 15 October differed somewhat. 'John Horsman came along and noticed that only the top edge of the spoiler was covered with dead bugs and oil spots,' related Peter Falk. 'So he said-and we saw it at exactly the same time-that the air was not going down to the bottom of the spoiler. He said that we could not build a car with a spoiler like that, but that we could build up the rear of the car with sheet aluminium. So that's exactly what his mechanics did. We had a lot of aluminium sheets prepared for this test, to make the spoilers higher and higher.'
Falk thus insinuates that Porsche was preparing to try a higher tail during the tests and that it was aware that it might be useful, but clearly it hadn't done so until Horsman suggested a trial. This has to be viewed against the background of the 917's origin. It was the personal creation of Ferdinand Piëch, now head of all Porsche engineering. From nose to tail it was designed as an ultra-low-drag racing car.
Downforce, or even the mitigation of lift, wasn't on Piëch's aerodynamic agenda. It's likely that any changes that would have increased drag-like a higher tail-would have been seen by Falk and Flegl as an admission of defeat. With the Englishmen doing it, they could divert any blame to them. Significantly Walter Näher's 917 book, based on the test reports in the archive, makes no specific mention of the British contribution. 'John Wyer's technicians' get a mention but with no indication of what they actually did.
Under Horsman's direction the 'desecration' of 917 008 was carried out by JW mechanics Ermanno Cuoghi and Peter Davies. 'To the horror of the German observers,' wrote Horsman, 'Ermanno and Peter snipped and riveted the rest of the afternoon but were not able to finish the job by the time the circuit closed.' When they wheeled it out the next morning, 'it looked very ugly, and Brian Redman was rather rude about it.' Peter Davies took the picture of the tail that appears in this column.
Redman it was who first took the aluminium-tailed 917 onto the Österreichring on the morning of 16 October. Instead of heading for the pits after a couple of laps, as before, he stayed out for seven. His first words on returning were, 'That's it-now it's a racing car!' 'Those were words of sheer joy to me,' recalled Horsman. 'After months of being a monster, the 917 was tamed.'
'It was a solution that came from all of us,' summed up Peter Falk. 'Later Mr. Wyer and Mr. Horsman said it was their work. And we naturally told Mr. Piëch that it was our work! But it was really teamwork.' Though overstating Porsche's role in the bodywork transformation, this comment did reflect the importance of the successful result, which proved to the Germans that their new English partners had something to offer.
Working back and forth the between the two 917 coupes, the engineers made them faster as well as better. With the wedge-profile tail the lap time dropped immediately to 1:45.6. With Firestone's tires plus chassis changes the time finally dropped to 1:43.2, to the credit of Kurt Ahrens.
'We thought we might have some trouble convincing Porsche to go along with the new shape,' said John Horsman, 'but they surprised us and were converted to the new gospel of downforce without any further discussion.' Such test results, which set the seal on the 917's successes of the next two seasons, couldn't be ignored. - Karl Ludvigsen"