Driving on the ceiling — formula1 racing aerodynamics Ask MetaFilter

Driving on the ceiling - formula1 racing aerodynamics Ask MetaFilter

Driving on the ceiling

It’s often quoted that a Formula 1 race car creates enough aerodynamic downforce to let you drive it across the ceiling. Has anyone ever proved this? If not, why not?

By the way, I’m not suggesting that you could do this on your bedroom ceiling. I just can’t believe taht no-one has built a ‘barrelroll’ type track to prove the point on. Yeah, it would be expensive, but in F1 budgetry terms, it’s sod all.

posted by twine42 at 7:10 AM on September 11, 2006

because you’d have to get it up on the ceiling first, F1 cars have very little ground clearance, so any ramp would have to be really big. Also, if something goes wrong, that’s a really expensive car to wreck.

posted by atrazine at 7:11 AM on September 11, 2006

From Wikipedia:

Such an extreme level of aerodynamic development means that an F1 car produces much more downforce than any other open-wheel formula; for example the Indycars produce downforce equal to their weight at 190 km/h, while an F1 car achieves the same downforce:weight ratio of 1:1 at 125km/h to 130km/h, and at 190km/h the ratio is roughly 2:1. Therefore, theoretically, F1 cars can drive upside down from 130km/h.

Whaddya mean why haven’t they done this? Um. cost of building a road where one could gradually spiral into this position at over 130km/h, the possibility of something breaking and losing downforce etc.

This is one of those situations where the theory is enough.

Oh, also, it may not actually be possible. An F1 car does create enough downforce to support its own weight, but only at high speed. I don’t know if there is enough ‘spare’ downforce to maintain traction (and thus, speed) with the weight of the car pulling the wheels away from the surface.

posted by atrazine at 7:14 AM on September 11, 2006

Easier than building a monster spiral road would be to put one in a wind tunnel strapped to a ceiling then as wind speed increases loosen the straps.

posted by zeoslap at 7:40 AM on September 11, 2006

Aside from the traction problem (great call, atrazine), some systems on Formula One cars are probably gravity fed.

posted by Chuckles at 8:01 AM on September 11, 2006

atrazine is onto something. The wiki article says the downforce generated at 130 km/h is 1:1 — in other words, equal to the force of gravity (call it Fg) pulling the car downward. So the total downward force acting on the car is 2·Fg. Put the car on the ceiling, and the two equal forces are now acting in opposing directions and cancel each other out. The would be no force keeping the tires on the ceiling.

At 190km/h, it’s a different story. Since the ratio of downforce to weight is 2:1 at that speed, turning the car upside down would result in an upforce equal to the weight of the car. It would be as if the car were driving right side up with no downforce. E.g. Theorerically, it would stay on the ceiling.

And zeoslap’s test method is the way to go.

posted by pmbuko at 8:03 AM on September 11, 2006

Enough already, someone should contact asavage and have him and his fancy tv show prove this once and for all.

There’s an easier way. Put the car into a wind tunnel on top of a large scale. Tare the scale, then fire up the turbines. When the scale reads the same as the weight of the car, you’ve reached the speed at which it could theoretically hang upside down.

chrisamiller: But then you don’t get to see the car hanging upside down from the ceiling.

posted by zeoslap at 11:02 AM on September 11, 2006

And yet, I don’t think anyone here is looking for mere simple proof. I think we’re looking for an actual upside-down-driving F1 car, am I right?

I have to say, I do indeed want to see schumacker hanging from the ceiling, but hanging the car from the ceiling in a wind tunnel is a damned good idea too!

Lets be honest here. how many of us know important things but never really believed them til they saw them? I don’t care how we do it, I just want my upside down F1 car, godamnit. )

posted by twine42 at 11:12 AM on September 11, 2006

It’s possible. I’ve had discussions about it, if you took the car hypothetically through a corkscrew or something, however there are many risks involved (traction, side force) that would put the driver in extreme peril if it were to fall (effectively killing he/she).

Why haven’t they tested it? Why would they design a facility and test a $14 million car in order to prove a physical factoid?

btw, a lot of street cars can produce enough downforce at certain speeds to ascertain this as well.

let me rephrase one last point: getting the car in that position where it will drive upside down is the hard-part. Any externalized force could throw it out of wack and cause it to fall. How to minimalize those externalities en route to getting the car upside down? Very difficult.

It’s not possible for the cars as they are currently design. There are many pants of the engine and gearbox that depend on gravity to function — the lubrication system, for example.

posted by milinar at 11:52 AM on September 11, 2006


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