14 replies to this topic

[Lutz G]

After reading the "Laffite, Depailler & Ligier in 1979" Thread...

"the stiffness of the ligier frame was good ,typical ducarouge stuff .the problem was aerodymical . it was the early days of ground effect . downforce generate by the venturi/ diffuser was doubling every 6 months . from 500kg in 78 to 2000kg in 1980. the ligier was a huge step ahead of the lotus 79 but 6 months later it was already out of date"

...I wonder about the g-forces during the f1 wing car era. I mean no short peaks like in modern f1 during breaking, just think about 1981, the infamous Hockenheim Ostkurve and the g-forces on the drivers . IMO in quali trim it was almost flat in 5th gear. Did the teams had any g-force data back in the early 80s? "Curva del Sol" (sp?) in Interlagos was also interesting...

Lutz

[Henri Greuter]

I have read that back in 1982 in the Brazilian race there was one corner where the cars pulled 6G momentarily.

Henri

[Lutz G]

6 G - wow! Which corner?

1982? IMO the GP was in Rio?

Here's a map of the old Interlagos circuit:



If my memory serves me well many drivers had problems in that Curva Del Sol to keep their head up...

Lutz

[nmansellfan]

Originally posted by Lutz G
6 G - wow! Which corner?

1982? IMO the GP was in Rio?

Here's a map of the old Interlagos circuit:

Lutz

It was in Rio, yes.

I don't remember the race at the time (i was 4 years old in 1982) but in '89 Patrese had a camera on his Williams during qualifying and the curve at the end of the back (main?) straight called Sul was a 'drop a gear but keep your foot in it' job. It was taken at at least 150 mph back then i reckon, it might have been even faster in the ground effect days.

[Lutz G]

Here's a map of Jacarepaguá- - it must be the ultra fast corner to the right...



From Prueller's "GP Story 1982":

-snip-

(...)

7 seconds faster this year, -15 seconds compared to Reutemann's lap record.
Lauda: "it's impossible to keep your head up after 10 laps" (...) up to 6 G

-snap-

BTW: I wonder if today's "Stiernacken" like M.Schumacher would get the same problems...

That rio corner seems to be similar to the Oskurve at the old Hockenheimring - but in Rio it was 4th gear flat (Prueller/ GP Story '82) and the Ostkurve was IMO in 1981 almost flat in 5th gear!
So the g force data of that ultra high speed 290 km/h Hockenheim corner (Auto Motor & Sport) would be *very* interesting. Can anybody help?

Lutz

[Lutz G]

Got mail from Marc Surer:

Williams ING Frank Durney told him - approx. 4 g at the Hockenheim Ostkurve!

http://home.tiscali....hockenheim.html

BTW: Love this quote from Marc (sorry - no time for translation ;) ) :

"In der Kurve verschiebt einem die Fliehkraft bei 290 den Kiefer."
(ATS Pilot Marc Surer 1980 über die Hockenheim Ostkurve)

Lutz

[David M. Kane]

Parker Johnstone, the former Champ Car driver and announcer once told me that if you suddenly change the direction of a ground-effects car by more than 13 degrees suddenly you could loss 70% of the downforce! He is an Engineering Graduate of the University of California-Berkeley, so I think that is a valid statement. Now that is scary. I have only driven one ground-effects car, A F2 Ralt RT-4...it was pretty amazing and I made no sudden direction changes at speed!

[Lutz G]

Originally posted by David M. Kane
I have only driven one ground-effects car, A F2 Ralt RT-4...it was pretty amazing and I made no sudden direction changes at speed!

Very interesting! BTW: Ist that "Ralt RT4" the car in the first home computer racing sim "Revs"?

http://home.tiscali.de/webgoe/revs.jpg

http://home.tiscali....bgoe/c645e.html

Edit: Ooops you wrote F2 not F3, ok. But perhaps that F3 Ralt got also these sort of wingcar side pods?


Lutz

[Cirrus]

The term "Wing Car" is a bit of a misnomer. It was originally applied to the Lotus 78, because of it's wing-shaped sidepods (not unrelated to the wings of the De Havilland Mosquito). Peter Wright. and the Lotus team soon realised that the huge downforce was being achieved mainly through the behaviour of the air beneath the "wings", rather than the relative behaviour of the air beneath and above the sidepods.

Ron Tauranac (who designed the RT4) was the first designer to apply this ground effect to small-formula cars in an effective way. I seem to recall that some F1 drivers at Dijon in 1979 were "greying out" due to the sustained G forces, and at the time, the possibility of F1 drivers needing G suits was discussed. I also remember a driver saying that the G forces were so great, that he was having difficulty moving his foot from the throttle pedal to the brake - now that is a frightening prospect..........

[fester82]

the possibility of F1 drivers needing G suits was discussed

As a former fighter pilot that has experienced over nine Gs on many occasions, one needs to understand the forces are apples and oranges between flying and driving. The G-loads are vertically oriented when flying, however they are lateral when driving - unless one is driving on a banked track (which I believe contributed to the cancellation of the Texas Champ car race a few years back). G-suits work by constriting the lower extremities and forcing the blood to the brain and eyeballs, but under lateral loads, the blood doesn't pool in the legs. Therefore, G-suits are of little use, but head restraints were popular with Champcar drivers before the cockpit sides were made higher. One could conceive of articulating cockpits to convert the lateral loads to vertical, but I believe the expense and weight would not make it viable.

The other factor in the equation is the length of time. While in the flying world, the forces are of an intense nature, they are usually fairly short duration-wise. A 2-3 min engagement maybe typical with a period of time before the next event. However, racing can last for hours and fatigue will build up over time and moving ones foot from pedal to pedal at 3-4 Gs would not be easy either.

change the direction of a ground-effects car by more than 13 degrees

Mr. Johnstone was refering to yaw slip (rotating the car about the verticle axis) of 13 degrees that causes the loss of downforce and not just a direction of travel .

[doc knutsen]

Originally posted by Cirrus
[B. I seem to recall that some F1 drivers at Dijon in 1979 were "greying out" due to the sustained G forces, and at the time, the possibility of F1 drivers needing G suits was discussed. I also remember a driver saying that the G forces were so great, that he was having difficulty moving his foot from the throttle pedal to the brake - now that is a frightening prospect.......... [/B]

In the 1973 film from the Nordschleife, in-car with the ISO-Marlboro Williams entry, JYS notes that "going down the Fuchsroehre, the forces are of such a magnitude that a driver cannot take his foot off the throttle even if he wants to.." He goes on to say that during one race at the old Nurburgring, a driver experiences more in the way of fear and animosity than many people experience in a whole lifetime.
Wonder if many of to-day's heroes recognize those emotions while undertaking a software-optimized jaunt around Magny-Cours.;)
Incidentally, G-suits would not be much use in a racing car as the forces are mainly lateral.

[Lutz G]

Originally posted by doc knutsen


In the 1973 film from the Nordschleife, in-car with the ISO-Marlboro Williams entry, JYS notes that "going down the Fuchsroehre, the forces are of such a magnitude that a driver cannot take his foot off the throttle even if he wants to.." He goes on to say that during one race at the old Nurburgring, a driver experiences more in the way of fear and animosity than many people experience in a whole lifetime.

Wow! In that of course in the pre Wing Car days...

Lutz

[mat1]

Originally posted by Lutz G


Wow! In that of course in the pre Wing Car days...

Lutz

Stewart mentioned the Fuchsrohre, which is a steep downhill, with a sudden upturn at the end. The car, including JYS, in deeply compressed in the springs (and on the bumpstops), and that is the effect Stewart is referring to. It has nothing to do with wings or corner speed, just with stright line speed. In a normal car, you will experience the same effect, if you dare to go as fast as stewart did over there.

mat1

[Lutz G]

I know - I just wanted so say - even with the early 70s cars you have (at the gruene Hoelle) such effects (of course not in corners, etc).

Lutz

[Ralliart]

In the film "The Quick And The Dead", done during the '73 season, Francois Cevert is interviewed at one point and says that the cars are, at times, serving up 2Gs - lateral and longitudal.