Mercedes Proves The Impossible – Drives The SLS AMG Up-Side Down… Or Do They?

The tyre were lift off the tunnel when upside down....and look like were luckily that the car swing continuously so that will land on other side

Its much more harder in the tunnel. As there is no ramp to launch it. So the car actually barrel rolls (stunt driving) instead of doing a loop (track). The Merc one is believable as the loop is very small. But like any stunts, there are people who calculate and do toy test first. hahaha.

Just a gimmick. Neither the SLS nor the Renault generates enough downforce to be able stick on the ceiling of a tunnel. In the Top Gear vid it actually makes because it's making use of centripetal forces (going round the curvature) not downforce and actually almost ended in disaster. The Renault particularly would generate lift instead of downforce at speed.

However I do recall that about 10 years ago or so McLaren actually did it with their F1 car. F1 cars certainly generate so much downforce beyond a certain speed that it can theoretically be driven on the ceiling.

If memory serves me right Mclaren used and old wartime wind tunnel in East Germany which had a very long tunnel. With max downforce car configuration and special mods gearing and safety, and thanks to the serious wind generated by the tunnel the car only had to do something like 30mph to demonstrate the feat

haha... that TG clip was a done as a joke lah (well, at least that's how i looked at it).

Makes you wonder how much car they 'turtled' to get it done. hahaha

jus a very theoretical q&a, downforce is created by using aerodynamics, in an open track that is possible, but in a tunnel, air is limited, even tunnels sometimes need their own ventilation fans.

so, to say that downforce is enough for a car/f1/sls amg etc for a car to travel upside down in a tunnel where air is limited, seems impossible to me.

wat topgear did, wasnt to prove about downforce, it was jus using d momentum of d car to spin one circle, jus like those x games stunt where the bikes or skateboarders go in a loop.

If you say "Air is limited inside a tunnel", how come you dont have people dying of suffocation coming out of our SMART tunnel? Or any other tunnel for that matter? The way you write suggests that there is a vacuum inside the tunnel. Ventilation and Vacuum are two very very different things here. Downforce generation via aerodynamics doesnt need oxygen. It just needs a medium to generate the forces required. Its not like the panels are "breathing" oxygen or anything...

But I agree with your other point. These two videos have nothing to do with "downforce" as we understand the term. They are just using momentum and centripetal forces to do some stunt driving...

As I mentioned, Mclaren was able to do it successfully with their F1 car many years back in a tunnel which was actually an old wartime WINDTUNNEL. If I recall, the wind tunnel generated 120 kph wind while the car did 30kph which equates to 150kph windspeed on the car.. or was it in 'mph'I wasn't sure but probably kph logically.

its more momentum..not downforce

Wll break out the Hot Wheels set and make it happen!

@Lelek:

Ppl dont die from suffocation in the smart tunnel due to the availability of ventilation fans. Its BASIC knowledge that major tunnels such as smart tunnels or the uk-france underground tunnel, require ventilation for human breathing purposes. Try asking the smart tunnel guys to off the ventilation fans, if you can stay alive for 1 day or even 2 hours. Prolly u can make a new breakthrough theory in human science.

Furthermore, im NOT suggesting its a vacuum environment. Its like a hose, how much air is available in a hose, compared to an open free environment. And also, with that limited amount of air(doesnt necessary means oxygen), it is highly unlikely to be able to generate downforce.

In layman terms, how can u use aerodynamic when there is no air? U cant even use the term 'aerodynamics' anymore. do u think gt-wings will work if it wasnt used in open space? Prolly that gt wing will end up better than u in a tunnel without ventilation.

@A1 diablo mentions that Mclaren did it, IN a wind tunnel generating 140kph speed of wind.

Smart tunnel, or watsoever tunnel never generates that type of air.

it's both momentum & aerodynamic. if aerodynamic is not in place, a van can do as best as sls did.

Knowledge, you don't have to be sarcastic. Lets discuss in a matured way.

Obviously, I notice the ventilation fans, and obviously, those fans are to ventilate the exhaust fumes out and fresh air in. Glad we can both agree on that.

And you stated that you are NOT suggesting that there is a vacuum in the tunnel. We both agree on that as well. Which means, we both agree that there IS air, and that its the same pressure as open air.

So, how much "air space" do you think is needed for the aerodynamics to work?

My question is basically, whats the difference between a ceiling height of a few meters away from the aerodynamics, as opposed to an open area? Mind you, I am talking about stagnant air. NOT wind thats generated in a wind tunnel.

In other words, what do you mean by "Air is limited"? Limited in what way? Pressure? You already stated that you are not saying that there is a vacuum in the tunnel. Volume? Once again, how does ceiling height affect aerodynamics? Quality? Doesn't matter, as the aerodynamics are not living things...

So, limited, ... How?

If you think downforce doesnt work in the tunnel, try this very simple experiment.

Drive at 110. Put your hand out the window and angle it downwards. Can feel the wind pressing your hand down?

Do the same inside the tunnel. According to you, you will feel less (or none?) downward pressure inside the tunnel.

If that is true then F1 cars would lose a LOT of stability barreling through the Monaco circuit at the tunnel section.

Knowledge, you might have something here after all. After googling extensively, I found this...

"a car can lose 20-30% of its downforce due to the unique aerodynamic properties of the tunnel"

How to explain this? I mean, you already said "air is limited" but how?