Porsche 917, high speed weave

Sorry to pick other people's brains when I should look in a book, but mine are all 657 miles away!

Did the early short tail 917 suffer a high speed weave, hence the later long tail version? It was mentioned to me the other day, along with the comment, "something to do with the narrow tyres"

A] They weren't that narrow, but maybe the width ratio front to rear might have caused something?

and B] I thought they were aerodynamically pretty good?

They did have some fantastic paint jobs as well, the Pink Pig, the blue/green swishy one and the GULF schemes have to be some of the best, ever..........

The original 917 langheck as homolgated in '69 with the bolted-on long tail and 'reactive' flippers was as long as the 917 ever got, I believe. Frère's "Porsche racing cars of the seventies" shows both the longtailed Le Mans cars of '70 and '71 (the JW one with blunter nose and the the faired-in wheels) being shorter. He also implies that the long-tails were used for higher top speed at the expense of handling, although the shorter car was thought to be fairly nasty as it was...

Ironically, despite all the 'trick' Le Mans cars (long tails, wheel fairings, the 917-20 Pink Pig) both the victories were with the 'K' type with the shorter, higher tails.

Frère gives loads of development detail and aerodynamic figures, but without re-reading it all I don't know if he specifically mentions straight-line stability He says, too, that wider wheels and tyres improved handling but changes to bodywork and aerodynamics were more significant.

I don't know if Peter Hinsdale covers any of that in his book; I think I've got that somewhere, but haven't looked at that for ages. I'll see if I can find it.

When I looked at the title of this thread did I think it was about hairpieces?
....it's allright, I'm not staying long.....

Now why on earth would you be thinking about hairpieces, Gary?

So the high speed instabilty was caused by hair wrapped around the hubs!!!!

that's more like it !!

Cheers Tony, that seems to prompt my failing brain! Still one of the best cars EVER. If only I could find the one road going version, and then find the money to buy it!!

As a further aside. Years go I was asked to do some research for a book "written" by Beki Adams, she who used to be on Top Gear, now a reclusive buhddist apparently. It was abour famous cars and what had happened to them. I picked the 917 given to Steve MacQueen after the film Le Mans. Steve Wright, his mechanic said that when MacQueen's collection was opened up, the 917 wasn't there. Did it ever resurface?

I believe the ex-McQueen 917 is now owned by Jerry Seinfeld.

I recall a website - found through a link given here on TNF - that attempted to account for every 917 chassis ever made: all the coupes, the Can Am cars (including multiple 917-30s - I'd previously thought there were only two), replacement and unused spare chassis, the later Kremer car and so on... but haven't been able to find it recently. Any ideas, anyone?

There used to be a site called the 917 Archive that is no longer live.

Now, we have this useful site -- a 917 Registry:

http://962.com/registry/917/index.htm

some nice cars for sale too! Lotus 98T/3 and a Gulf 917

The entry on the 917 in Anthony Pritchard's Sports Racing Cars puts it down to some aerodynamic issues in the long tailed cars. Apparently the Wyer team started cutting away the fiberglass body and reshaping things with aloominum sheeting, which made the car rather more stable and eventually led to the short tailed versions, which were a bit more stable. Relatively speaking, of course!

-William

The 917 is right at the top of my list too -short tailed of course. Every time I see one, a picture of one or hear one my knees turn to jelly. If I were a rich man....
I don't think the straight line stability is limited to either combination of tails, every moving picture I see of these things they are weaving and squirming under brakes. From front on they look like one of the least stable cars on the track. They really were the most fearsome, spectacular yet succesful racing cars ever built. As close as we ever came to the Mercs and Auto Unions of the 30s I'd guess.

Originally posted by Huw Jadvantich
They really were the most fearsome, spectacular yet succesful racing cars ever built. As close as we ever came to the Mercs and Auto Unions of the 30s I'd guess.

couldn't have said it better myself....

McQueen 917 is owned by Seinfeld, we saw it on a flatbed last spring as it was being transferred to Jerry's facility in Santa Monica near the SM airport.

I've talked a few times with Mr. Leo Kinnunen about the 917s. The last time we met he wasn't too impressed by the way his Gulf Porsche 917 e.g. from 1970 handled. He said the cockpit was usually "warm", the car wasn't too stable and it was very nervous under braking. He didn't complain about the engine, though... And about Mr. Kinnunen: he is a true gentleman!!! I believe he isn't as respected as a racing driver as he should be.

Its true, we all remember Pedro and Seppi, and tend to forget that most of Pedro's great victories had Leo alongside him. John Wyer was nobody's fool and clearly respected Leo's abilities in what was a very difficult car.
From this distance it is probable that we see Leo as being able to lap competitively and be kind to the car whilst Pedro did the stellar stuff.
What were the differences in lap times, and does anyone remember Kinnunen doing some spectacular lappery himself?

Originally posted by Greatest
I've talked a few times with Mr. Leo Kinnunen about the 917s. The last time we met he wasn't too impressed by the way his Gulf Porsche 917 e.g. from 1970 handled.

I recall an Autosport test where Derek Bell tested a 917, he wasn't very impressed either

Slightly O/T, but Kinnunen's great lap at the Targa Florio in a 908/3 was clearly not the work of a slouch.

I don't have any comparisons handy but Targa Florio is clearly a place suited for a rallyman like Kinnunen.

Didn't he go something like half-a-minute under the previous record?

Originally posted by 2F-001
Didn't he go something like half-a-minute under the previous record?

Kinnnunen's 1970 fastest lap was the fastest lap in the history of the race, 33'36.0". Previous year's fastest lap was Elford (908/02) in 35'08.2". Best practice lap in 1970 was Siffert or Redman in 34',10.0".

Yea, it was the 'low drag' aerodynamics at the rear of the early 917s that was causing the rear end lift and thus the frightening high speed instabillity...

As WDH74 mentioned, it was at the Wyer/Porsche test at the O-ring Austria in late 1969 where the 917 was basically transformed into its drivable/racewinning state. The Jo Siffert Can-Am 917PA (basically a 908 spyder with big engine) was also brought to the track to provide a direct comparrison to the 917 longtail (the drivers much preffering the handling of the Can-Am car) - and essentially this was the inspiration for the short-tail 917s. Basically rear spoilers were fashioned from aluminum sheet and fitted to the tail of the car (very similar to what occured with the Gt40 program) - predictably as the height of the spoilers was raised the car became much more stable. When it was noticed that the airflow was only reaching the top of the spoiler, the rear decklid was then built up, producing the familiar upward rake of the 917K... All done very primitively in these the early days of aero knoweledge, but obviously very effective!

In 1971, the rear-end lift on the longtail was cured with the revised rear deck, concave front end, side fences, wing etc. - without sacrificing the essential, low-drag shape. Throughout the development, I believe the brakes were also up-rated and unsprung weight reduced, all aiding the stability of the car under braking...

He said the cockpit was usually "warm",

Yes - especially on the earlier cars because the exhausts ran forward, exiting right at the cockpit (which was unvented - no holes for airflow!) and there was hot fluids were transported via the chassis tubes!

Originally the wheels were 9" wide at the front and 12" at the rear, because "der compooder zez dat is enough"..................and Frank Gardner is rumoured to have replied "Der compooder isn't driving this blardy thing round the 'Ring!"

In 1970 the wheels went up to 10.5" and 15" wide (source: 'Porsche 917 Super Profile', by John Allen)



Paul M

Didn't the 917 have a locked diff? Could that have influenced its straight-line behaviou?

I'm going to have all the answers down the Tabac now, my French neighbour is going to wish he'd never mentioned it! Thank you everyone!

In "Race of my life" - Autosport of October 19, 1989, Leo Kinnunen said :

I'd been picked by Porsche to drive with Pedro Rodriguez, who was John Wyer's own choice. It was soon obvious that I was expected to be the anchor man in the team as team manager David Yorke kept telling me to go slow, not to risk anything.
In a way, that was fine with me, because our Porsche 917 really was a beast to handle. Pedro insisted on having an impossible understeering car. Very early in the season I once managed to have the car in more neutral settings and started beating Pedro's times. Thereafter he would always have his way with the settings of our 917. An even more serious handicap was having to adjust to Pedro's driving position. He wanted to drive with his arms straight, virtually lying on his back. Although we were almost the same size, his arms were longer than mine and I had to support myself hanging on to the steering wheel!
So it was just as well my team mate did the bulk of driving in the 917, as I felt the car was downright dangerous for anyone else to handle. I've got to handle it to Pedro though, he had an amazing stamina coping with such a pig of a car for long stints, only asking for the odd aspirin afterwards.
If the 917 had been properly set up, I could have been a lot quicker in it and I'm sure Pedro would have benefited too. We both had a driving style which was quite gentle on the car, we could have been an even better pairing in endurance racing.

There's loads of info on the early 917 in Motor Sport February 1998 pp88/9 Richard Attwood - The Worst Car I Ever Drove. Too long to type the whole article now, but he says that in practice at Le Mans "The further you went down the Mulsanne straight, the less you could see though the rear-view morror, because the back of the car was just coming off the ground. At the kink, you had to brake and downshift, things you wouldn't dream of doing in a decent car. The other problem we had was these new Goodyear tyres on very narrow wheel rims, which started chunking at speed. That was fortunate from my point of view because we had to slow down a bit on the straights... which is exactly what Iwanted to do."

...."We went back to the factory for a debrief and they promised to redesign this that and the other. Then Brian Redman went testing it at Zeltweg, but although they'd changed all kind of things under the body, it still had all the same problems. It wasn't until John Wyer got involved in the project that it started to improve. He realised the drivers weren't all idiots - whereas Porsche presumably thought they were - and he reacted to the drivers' inputs. First they removed the rear tail section completely and at once it was immediately and substantially better. Then came the upswept tail to give it some downforce, and after that, the car was just fantastic."

..."I was lucky in that I drove a lot of good cars, and in some ways the Porsche 917 was probably the best, certainly the most successful. But that original car in 1969 was definitely the worse.

This thread's got me wondering: What kind of lap time do you think a 917/30 could have set around Le Mans?

It's too bad Group 7 cars weren't able to compete there. That would have quite a sight (and sound)!

Jo Siffert said of the 917 "Under accelaration, the chassis flexed so much you did all the steering with your right foot. There was a steering wheel, but that was just put there so as to have something to hang on to...."

Originally posted by Kpy
There's loads of info on the early 917 in Motor Sport February 1998 pp88/9 Richard Attwood - The Worst Car I Ever Drove. Too long to type the whole article now, but he says that in practice at Le Mans "The further you went down the Mulsanne straight, the less you could see though the rear-view morror, because the back of the car was just coming off the ground. At the kink, you had to brake and downshift, things you wouldn't dream of doing in a decent car. The other problem we had was these new Goodyear tyres on very narrow wheel rims, which started chunking at speed. That was fortunate from my point of view because we had to slow down a bit on the straights... which is exactly what Iwanted to do."

...."We went back to the factory for a debrief and they promised to redesign this that and the other. Then Brian Redman went testing it at Zeltweg, but although they'd changed all kind of things under the body, it still had all the same problems. It wasn't until John Wyer got involved in the project that it started to improve. He realised the drivers weren't all idiots - whereas Porsche presumably thought they were - and he reacted to the drivers' inputs. First they removed the rear tail section completely and at once it was immediately and substantially better. Then came the upswept tail to give it some downforce, and after that, the car was just fantastic."

..."I was lucky in that I drove a lot of good cars, and in some ways the Porsche 917 was probably the best, certainly the most successful. But that original car in 1969 was definitely the worse.

Main problem was Piëch's stubborn insistance that low drag was of paramount importance for every Porsche!
He didn't want extra ventilation slots within the car because of the effects on the drag coefficient and so on, and that's why he ordered watercooled driver suits for one race...

When late '69 in Austria the car was revamped by Wyer the team manager had one big problem. He had to tell Piëch who was to arrive later on during the test session to have a look the following.
A: the car handled very well at long last.
B: the car doesn't look as you know it anymore.
C: Can we please continue in this direction because at least the car works by now!

Fortunately, Piëch gave in at last, but he didn't surrender easily, hens the Langhecks returning to Le Mans after all in 1970 since "Low drag was of paramount importnce for every racing Porsche"

Henri

Originally posted by biercemountain
This thread's got me wondering: What kind of lap time do you think a 917/30 could have set around Le Mans?

Lap times for Donohue and 917/30 at other circuits would be interesting too - Monza, Osterreichring, Spa... but I guess we can never be sure.

For some general comparisons though, 917Ks ran at Watkins Glen in both the 6-hours and a few in the Can Am race - although without looking I forget when the circuit changed there.

The 917/30 tested at Ricard (very vaguely similar in nature to Le Mans, one might say?) - a best of 1m 46s is cited, which is damn fast; that would have been miles ahead of the Grand Prix grid of the day. Lap times at a GP at Ricard didn't get under that (although when they did, they did emphatically) until the arrival of the Lotus 79. According to who's account one follows (I've only checked Frère's and Donohue's), 917/30 with less downforce, and hence laps a couple of seconds slower, hit between 231 and 240 mph on the Mistrale straight (restricted by gearing, Frère implies) - which is only a third the length of the straight at Le Mans - so I don't think they found out if would top out there or go higher. I can't, for now, find any reports of 'regular' 917s testing at Ricard, although I believe they may have done.

I'm guessing this thread has to do with the moveable flaps Porsche had the 917 in 1969 to keep the car going straight. Rolf Stommelen was the man driving this beast! After he won pole at Le Mans, the organizers told Porsche that they couldn't have moveable winglets. Therefore, Porsche locked the flaps in place and sent Stommelen out there. The car was weaving from one end of the track to the other at the Mulsanne at full song. Horrified at what they saw the organizers let Porsche run the moveable flap for this race, but told them to show up in 1970 without any moveable aerodynamic parts....

Originally posted by Huw Jadvantich

I don't think the straight line stability is limited to either combination of tails, every moving picture I see of these things they are weaving and squirming under brakes. From front on they look like one of the least stable cars on the track. They really were the most fearsome, spectacular yet succesful racing cars ever built. As close as we ever came to the Mercs and Auto Unions of the 30s I'd guess.

All I say is, "Thank goodness for the weaving and squirming." To watch Pedro and Jo driving as though the weaving and squirming wasn't going on left indelible memories for me. Apart from making long distance racing anything but boring.

Originally posted by Fiorentina 1
I'm guessing this thread has to do with the moveable flaps Porsche had the 917 in 1969 to keep the car going straight. Rolf Stommelen was the man driving this beast! After he won pole at Le Mans, the organizers told Porsche that they couldn't have moveable winglets. Therefore, Porsche locked the flaps in place and sent Stommelen out there. The car was weaving from one end of the track to the other at the Mulsanne at full song. Horrified at what they saw the organizers let Porsche run the moveable flap for this race, but told them to show up in 1970 without any moveable aerodynamic parts....

Attwood re Le Mans 1969 again:
"There was a hell of a row that year, because the car was fitted with these little moveable flippers and there was a big protest. Eventually, Rico Steinemann talked to the organisers and threatened to withdraw every Porsche from the race which was about half the field, so we were given the go-ahead. The funny thing is that these flippers were totally ineffective anyway. I doubt that it would have made a scrap of difference if we'd taken them off."

Since it's (almost) unanimous that the '69 917 was hard to handle. more's the wonder that at Le Mans that year, Vic Elford/Richard Attwood led by 50 miles with three hours left when a broken oil seal put them out - and set up the fantastic Ickx-Herrmann finish!...Elford relates his experience of driving a long-tail at Le Mans in '70 that puts one there (almost) in the cockpit...Elford has said that, for him, there was no indecisiveness when it came time to pick which Porsche 917 to drive - the langheck was the fastest car...as far as road racing with the 917-30, Elford relates racing one at Hockenheim in 1973

The 69 917 beast was the one John Wolfe was killed in, correct? On lap 1 at Le Mans. How was he in practice and qualifying compared to Elford, Stommelen, etc?
And, after the tragedy what did the organizers have to say to Porsche, since it was determined that the moveable winglets helped stabalize the car?

Herbert Linge (authorized by Porsche) teamed up with Woolfe and my guess is that Linge went for the grid position. I'm pretty sure to have seen a picture of the Woolfe Porsche 917 having its engine changed after practice.

Originally posted by Fiorentina 1
The 69 917 beast was the one John Wolfe was killed in, correct? On lap 1 at Le Mans. How was he in practice and qualifying compared to Elford, Stommelen, etc?
And, after the tragedy what did the organizers have to say to Porsche, since it was determined that the moveable winglets helped stabalize the car?

John Woolfe crashed his private 917 fatally at White House on lap 1. Porsche had tried to persuade him that Herbert Linge should start the race, but Woolfe insisted. The car qualified in 17th place, it's said that Kurt Ahrens set the time. Certainly Digby Martland, who was entered to drive with Woolfe decided that the car was beyond his capabilities and withdrew. John Woolfe was a wealthy British amateur who, with hindsight, should never have been driving the car. However this has nothing to do with the argument with the organizers over the moveable winglets. The 917s were permitted to use the winglets despite the rule against moveable aerodynamic devices. Or am I missing the point here?

Originally posted by Kpy


The 917s were permitted to use the winglets despite the rule against moveable aerodynamic devices. Or am I missing the point here?

Yes, Kpy, they were but we now have two different accounts of how and why. One is that cars were undriveable without them (as demonstrated by Stommelen) and were allowed to run, and other by Attwood that they didn't make any difference on the cars but organizers caved in because they were threatened that every Porsche car would be withdrawn from the race.

Seems interesting enough- wonder if we can come to the bottom of the matter...

And, since Woolfe crashed fataly with the moveable deals anyways, I tend to agree with Haywood. From what I understand, Woolfe had been at Le Mans before with a protype (chevron) the year before. He was not some GT club racer with only 5 races under his belt. He might have been way off Stommelen or Elford, but he had some crudentials. Now a days, there are guys racing at Daytona in Prototypes that have almost zero experience!
Does anybody know how far off Woolfe was in practice?

As far as I can remember from reading Time and Two Seats recently. Here goes

This was the last year of the Traditional Le Mans start and everyone runs to there car STRAPS THEMSELVES IN and drives off except apparantly who has time to strap themselves in. According to my account of the story (correct me if I am wrong) when he crashed he wasnt belted in. Sooooooo what do you guys think.

By the way Time and Two Seats is probably the greatest motoring book ever written very easy to read, full of interesting stories and facts and at 2254 pages for approx. $200US great value.

Lastly this all reminds me of Bathhurst this year where one of the leading drivers wasnt where his Nomex head gear and of course was called in to have it put back on !!!!!!!

Tim

f1steveuk - Have you ever seen this one? http://project917xxx...com/917v20.html

Originally posted by Wolf


Yes, Kpy, they were but we now have two different accounts of how and why. One is that cars were undriveable without them (as demonstrated by Stommelen) and were allowed to run, and other by Attwood that they didn't make any difference on the cars but organizers caved in because they were threatened that every Porsche car would be withdrawn from the race.

Seems interesting enough- wonder if we can come to the bottom of the matter...

Agreed. This is a very interesting point. But I've never seen any evidence that Stommelen, or anyone else, drove the car at Le Mans in 1969 without the moveable winglets, perhaps that was the case at the test weekend, but the winglet system was on chassis 001 shown on March 29 at the Salon Automobile de Genève . Certainly you will find this: " Your scribe recalls the way Stommelen’s car, well in the lead at first, seemed to take the fast Dunlop curve in a series of ‘hops’ as the German driver fought to keep control. " here: http://forums.autosp...&postid=2256506
DSJ wrote, in Porsche Past and Present, "Eventually the 917 was tamed, but not before John Woolf [sic ], one of the first customers, had been killed at Le Mans. This tragic accident was not really the fault of the 917, and the Porsche team had suggested that his co-driver, the experienced Herbert Linge, should take the first driving stint. Unfortunately, John Woolf was desperately keen to drive the car in the race, even though his racing experience was very limited. In the opening laps, at a time when limits are fine and experience is all-important, he crashed fatally at the infamous White House bends."
By all accounts Woolfe was not strapped in, but given that the car exploded on full tanks, it's doubtful that belts would have been any help.
As for practice times, I stated earlier that the car qualified in 17th place, but, http://www.teamdan.c...9/69lemans.html gives 9th place with a time of 3'35.6". All four drivers practiced the car, and I've yet to see a time that is stated as definitely being Woolfe's.