Driving upside down

[Erki]

I just read that at 160mph, SALEEN S7 generates enough downforce to theoretically drive upside down. Has anyone tried and succeeded doing such thing?

[walrus81]

I could try, but the ceiling of my loungeroom is just a tad too small to allow the SALEEN S7 to reach 160mph.

[Mark]

I can't find any evidence but I remember hearing someone saying that the driving upside down thing is a myth and just wouldn't work in reality.

[Dazz9908]

In F1 Magazine the stated that while possible to generate enough down force to do so, the engine and drive train rely on to many Gravitational operations like fuel and oil.

[raybak]

So if you ran an electric car you should have no problems then with gravitational effect on fuel and oil.

Ray

[Dave B]

There's no theoretical reason why a car which generates more than its own weight in downforce shouldn't be able to drive upside down - but some parts of the car rely on gravity being where you'd expect it, such as the fuel pickup being at the bottom of the tank.

If you could overcome those problems, and provide a suitably shaped track which would "flip" the car once it had achieved the required velocity, then you're in business.

[Mark]

It would have to generate more than it's own weight of course. If it just generates it's own weight then it is effectively weightless, and you don't get any grip with no weight. I would think that it would have to generate at least twice it's own weight to be actually able to get any drive.

[Dave B]

Theoretically (again) even 1 gram more than its own weight would be enough to make it stick to the track. Of course, whether there'd be enough grip to render the car controllable is another matter....

[Mark]

It would need more than 1 gram, remember that in order to stick to the ceiling it needs to be travelling in excess of 160mph, therefore in order for the tyres to have enough grip to be able to continue to propel the car forward at that speed, it will need to have a sustantial amount of weight on the tyres, otherwise they will just lose grip, and spin, and the car will fall to the ground.

[Dave B]

Ah, but we're only talking theory.

Think about it the traditional way up. A 1000kg car which generates 999kg of lift - not downforce! - would only weigh 1kg but still remain on the ground.

Of course it would be undrivable in practice, although you might be able to persuade Mark Webber or Peter Dumbreck to have a go... ;)

Flip the whole thing upside down and the car would only have to generate 1001kg of downforce to remain on the ceiling.

I don't know why I'm typing this because you're so obviously right about the grip required to actually drive the thing! :)

[Erki]

So we need a rocket powered car. Or a towed one.

[Mark]

Of course the downforce increases with the square of the speed (or something) so we might not need to go much above the 160mph in order to get the required grip?

[CarlMetro]

Has anyone tried ?

Nick Heidfeld tried in the US GP this year, but didn't realise you need a surface under your wheels whilst upside down :p :

[Dave B]

A nice ramp on the entrance to the tunnel at Monaco should suffice... :D

[fly_ac]

In F1 Magazine the stated that while possible to generate enough down force to do so, the engine and drive train rely on to many Gravitational operations like fuel and oil.

So If the car had a engine like a aeroplane, in theory it should then be possible ?

[luvracin]

So If the car had a engine like a aeroplane, in theory it should then be possible ?

Not neccessarily an aeroplace engine.

All you'd need is a fuel tank pump that swivels in order that the pickup is always submergerged OR you could have an accumulater in the fuel line(downstream of the pump) that continues to feed the engine when the tank pump is starved. Obviously you could only run upside down for a time determined by the volume of fuel in the accumulator though. Other option is to run on gas(natural gas).

On the oil side, you could potentially do it for a very short(a few seconds) burst before you started to have problems. It's not the same extreme case, but they already have to do some work to ensure the engines don't get oil starvation during high g cornering.

[schmenke]

The "fuel pick-up" problem would be eliminated if the car was fueled with a pressurised gas such as hydrogen.

[Donney]

I bet not even the Saleen boys ever thought they'd generate so much of a debate and such a cultivated one.

[tannat]

I just read that at 160mph, SALEEN S7 generates enough downforce to theoretically drive upside down. Has anyone tried and succeeded doing such thing?

The Saleen is a heavy car (~3300 lbs), and I'm a bit suprised it generates so much df at that speed...

[Erki]

I have read that Saleen weighs around 1200kg, that's way less than 3300lbs.

[Mark in Oshawa]

Aerobatic planes such as Pitts Specials or Yak's have piston engines that spend a lot of life being tossed around in various G manouevers. If they survive, then any motor can be made to go upside down. I figure if a car generates 5000 lbs of downforce, and it only weighs 2300 lbs , then it may have enough control. I guess we will never know, because the last time I looked, the closest thing we had to an upside down race track is the 40 degree's of banking at Bristol Motor Speedway, and we know the taxicabs racing there are more fun when they dont' have enough downforce!!!!

[fly_ac]

Aren't the tracks one find in Australia and New Zeeland already upside down. :D

[tannat]

I have read that Saleen weighs around 1200kg, that's way less than 3300lbs.

Factory site says 2950 lbs (1338 kg). Perhaps the figure I saw included driver and full tank of petrol...

I could see the FIA GT version weighing about 1200 kg....

[schmenke]

1,250kg

http://www.answers.com/topic/saleen-s7

[tannat]

1,250kg

http://www.answers.com/topic/saleen-s7

that conversion is incorrect

2950lbs/2.2 (appoximate kg conversion rate)= 1341 kg

[Erki]

I thought about the grip levels and such and I came to conclusion that it doesn't have to generate much more downforce that its own weight. If it is driving fast enough already and then goes upside down, the car doesn't have to accelerate but just hold its speed and that doesn't require as much grip.

Correct me if I'm wrong.

[schmenke]

that conversion is incorrect

2950lbs/2.2 (appoximate kg conversion rate)= 1341 kg

It's close enough ;)

2,950lbs/2.28 = 1,294kg

[Mark in Oshawa]

I thought about the grip levels and such and I came to conclusion that it doesn't have to generate much more downforce that its own weight. If it is driving fast enough already and then goes upside down, the car doesn't have to accelerate but just hold its speed and that doesn't require as much grip.

Correct me if I'm wrong.


Fine, you drive the car and tell us how you do!!! I would want more downforce than just a few pounds extra. One bump and boom.....you are on your head....

[Dazz9908]

Don't Aerobatic planes use Rotary piston motors?

[schmenke]

Some do I guess but I believe the Pitts Special is equipped with a standard Lycoming flat-4.

[Erki]

Fine, you drive the car and tell us how you do!!! I would want more downforce than just a few pounds extra. One bump and boom.....you are on your head....

Who said the "ceiling" has to be bumpy?

[Mark in Oshawa]

Erki, good point. I am still waiting of course for a race track on a ceiling. How would you pave it for that matter???? I don't think an ashphalt roller would have the downforce to make it smooth eh?

This upside down racing car stuff should be sent to the boys at "Mythbusters" on Discovery Channel in the US.

[Erki]

Could it perhaps be made from glass? The car only weighs a few pounds on that glass so it wouldn't break.

[Daniel]

Don't Aerobatic planes use Rotary piston motors?
You mean radial engines :)

[Dazz9908]

You mean radial engines :)
Most likely, thanks Dan! :up:

So do Arobatic planes have radial engines???

[Daniel]

You can have any engine in an aerobatics aircraft really :)

When I did training in a Cessna 152 which is semi-aerobatic the aircraft like all 152's had a flat 4 Lycoming :) But there are aircraft that have straight (car style) engines and V engines as well as Radial engines. It doesn't matter really. It all depends on the fuel and oil systems and so on as to whether an aircraft is fully aerobatic which means that it can fly upside down indefinitely (or until the fuel runs out :p )

[raybak]

all we need is one of those big storm drains with curved walls and see if it will work. I wreckon that it is possible but who want's to risk their car!!!!

Ray

[Erki]

all we need is one of those big storm drains with curved walls and see if it will work. I wreckon that it is possible but who want's to risk their car!!!!

Ray

Yep, that's what I was thinking too. No, not the car breaking part...but the curved walls part, once you have the speed necessary you just turn and go onto the "ceiling". Voila. I guess I have to email Johnny Knoxville to do it. :p :

[cosmicpanda]

you could have a paved ceiling if you used concrete... or if you perhaps laid the road the right way up and then turned it upside down and, I don't know, superglued it to the roof? :p :

But it's sad, the FIA's already legislated against having some sort of ramp to get the cars up onto the ceiling at Monaco (or anywhere else). Their regulations for circuits suggest a maximum banking of 10 degrees, I think. To get a smooth ramp onto the tunnel you'd need 180 degrees of banking. And the cars probably wouldn't be generating enough downforce at that point, anyway - the corner before the tunnel's pretty slow.

I wonder what slipstreaming a car upside down would be like?

[schmenke]

...I wonder what slipstreaming a car upside down would be like?

Probably not a good idea as the trailing car would lose much of its downforce :s

[fly_ac]

....... which means that it can fly upside down indefinitely (or until the fuel runs out :p )

.....or until the driver/pilot loose consciousness.......

' \ ' | " / '
- SPLAT -
, / , | . \ ,


:crazy:

[Valve Bounce]

There's no theoretical reason why a car which generates more than its own weight in downforce shouldn't be able to drive upside down - but some parts of the car rely on gravity being where you'd expect it, such as the fuel pickup being at the bottom of the tank.

If you could overcome those problems, and provide a suitably shaped track which would "flip" the car once it had achieved the required velocity, then you're in business.


I am sure Honda could provide the necessary bodgy fuel tank and fuel pick-up system to overcome this problem. :p :

[Dave B]

I don't know what you could mean... :angel: :p

[Mark in Oshawa]

Another thing, if you are racing upside down, and you miss the ramp to get back right side up, does the car leave the tunnel and then fly UP and then down as gravity takes over????