A question on historical approaches to ground effect cars

[manchild]

I don't think Robin Herd's wing-tanks on the March 701 would qualify as "gound-effects", though he had worked on the Concorde and clearly had an aerodynamic mind, which was obvious from the 711 when he also dropped the wing-tank idea...

Relatively small amount of DF, relative to late 70s/early 80s cars doesn't deny the principle and functionality. Fact that even today by FIA regs. floor must be flat simply indicates that these sidepods certainly generated downforce, otherwise FIA would ban only endplates and skirts, while allowing curvy bottom...

mmm "curvy bottom"

[xpensive]

Semantics here man, but perhaps you could call the 701 a "wing-car", when I doubt Herd's intention was to create a venturi-effect against the ground? If he had had that in mind, I am sure he would have thought of some kind of shielding arrangement, the competent engineer he was (is)?

As I remember it, those wings were actually fueltanks, why they were placed as low as possible anyway.

[manchild]

If he had had that in mind, I am sure he would have thought of some kind of shielding arrangement, the competent engineer he was (is)?

EDIT: They weren't for fuel. Fuel tank was similar to modern F1 - behind the driver's back and lower back.



http://www.f1-info.cz/f1foto/f1-histori ... h701-5.jpg

Regarding endplates, there were none even on wings. Not only March, but no other car had endpates as we know them today, if at all. Those were pioneer days of DF aero, and like many other things we find them illogical now.

Take a look at headrests as another example - none!

[xpensive]

I stand corrected man, perhaps I have the sidepod-tanks confused with a certain McLaren, the M7?

Headrests? I guess that both drivers, bolts and brackets were stonger in them days, look at that
tiny insex-bolt fixing the engine to the chassis? Was that really load-bearing, I wonder...?

But they did indeed have rear-wing enplates in 1970, check out the Lotus 72, Ferrari 312B and Tyrrell 001.

[DaveKillens]

Headrests? I guess that both drivers, bolts and brackets were stonger in them days, look at that tiny insex-bolt fixing the engine to the chassis? Was that really load-bearing, I wonder...?

A bit off-topic, but yes. The engine is a Ford Cosworth DFV.

The main connection between the engine and the chassis was via two bolts spaced 9 inches apart at the bottom of the monocoque with additional connections at the reinforced cam covers.

http://www.ddavid.com/formula1/lotus49.htm

Although if I was a driver, I would be uncomfortable unless those bolts received a full battery of non-destructive testing each and every time it was possible.

[xpensive]

Of course it's a Cosworth, but were those brackets/bolts relied upon as load carriers?
Stiffness must have been none xisting, relying on a friction-clamp?

[DaveKillens]

I do not feel comfortable that so much load and vibration could pass through such a connection, but it worked, and I must assume it was engineered correctly.

The first car to use the DFV (as all historians are well aware) was the Lotus 49, and the fastening method was much more robust. The plate that fastens to the cylinder heads is fastened to the chassis with multiple rivets.



Leap forward to the Lotus 79 (same engine) and you can see that Chapman has changed the fastening method to just one bolt.



Please note that this picture is of a Lotus 79 model. But it also allows me to return to the original topic, and give a brief mention about the Lotus 79,
the first Formula One car to fully realise the potential of ground-effect aerodynamics.

This brilliant car revolutionized Formula One, and signalled a new era. It was a winner out of the box, and everyone else had to copy the important features of the 79 in order to remain competitive.



This illustration of the bottom of a Lotus 79 displays what the underbody was like. The venturi tunnels were smooth and uninterrupted, and had it's own airflow that was separate and distinct from such things as the radiators.
Also included in this illustration are the side skirts which sealed the side of the sidepods, and how they moved up and down in order to maintain a seal with the road surface. Naturally, they wore out quickly.

I figured that since this post was a bit large for me, I may as well throw in a picture of many things I really like and have respect for. The Lotus 79, Ronnie Peterson, and what is arguably the most beautiful paint scheme ever.

Ladies and gentleman, it is my honor and priviledge to present to you ...

[tok-tokkie]

Ladies and gentleman, it is my honor and priviledge to present to you ...

The front wing seems to have an inverted angle of attack in this photo. Wow the front tyres were narrow then.
I agree about the smart paint scheme and the huge significance of the aero of this car.

[DaveKillens]

This image illustrates the major difference in size between the fronts and rears. It's not that the fronts are very different than the present, but the rear tires.. whoaaa... WIDE.

The wings front and rear are set at shallow angles, very different from the present practice where huge angles of attack are common.

Back then, they were dealing with different priorities. The ground effects package offered not only increased downforce, but amazingly, lower drag. In fact, this allowed the car better acceleration and higher top speed.

Because the tunnels generated so much downforce, the wings weren't even necessary. In this scenario, they were used more for trim than attempting to generate significant downforce via the wings.

p.s. Not only was ground effects and the Lotus 79 a major turning point in the technical development of Formula One, but Ronnie Peterson was a very special person.

[xpensive]

There was an image from the 1980 South African GP, which claimed to show that Nelson Piquet's Brabham BT49
had the front wings set for lift, in order to trim the car properly. That massive was the downforce of the venturis.

[Roland Ehnström]

Please note that this picture is of a Lotus 79 model.

Actually it's a 78. Note the airbox. I have the same model I believe, 1/24 scale Tamiya.

[DaveKillens]

I stand corrected. You can always trust a modeler in accuracy and fidelity.

[xpensive]

Peddling semantics here perhaps, but I still regard the 1970 Chaparral 2J as the first true "ground-effects" car,
however with a different technology altogether. I know someone agrees with me there.

Actually, wear on the sliding skirts on the venturi-cars was not that bad, thanx to cheramic contact-strips.

[DaveKillens]

I went to a lot of trouble to state...

the first Formula One car to fully realise the potential of ground-effect aerodynamics

because although I'm sure I'm not the person X is referring to, I also believe that it really got started in the mind of Jim Hall.

[riff_raff]

When the ground effects cars in F1 were really working, they got rid of the front wings altogether: