Home » What It Takes To Drive A Car Upside Down, From A Man Who Aims To Try It

What It Takes To Drive A Car Upside Down, From A Man Who Aims To Try It

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It’s something you’ve probably heard a million times as a Formula 1 fan—that the cars make enough downforce that they could theoretically drive upside down. Of course, nobody’s ever actually done it, because practical concerns make proving the theory incredibly difficult. Regardless, one man is eager to achieve such a feat, and he’s stumped up the money to fund the necessary engineering work to make it happen.

Scott Mansell, known on YouTube as Driver61, has made it his mission to drive a car upside down, solely relying on aerodynamic downforce to keep him stuck to the roof of a tunnel. As he’s explored the project, and engaged engineers to work on the problem, he’s come up with a believable plan to pull it off. This involves a custom car and a custom tunnel, built specifically for the purpose of achieving this stunt.

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Choosing The Right Car

You might think that a Formula 1 car would be ideal for the job, but as far as Mansell and his team are concerned, that’s anything but the truth. For a start, F1 cars are incredibly expensive to buy and run, assuming you can even lay your hands on one. Modern examples are also rather heavy, pushing up towards 1800 pounds. The heavier the car, the more downforce you need to generate to drive it upside down, and thus the faster you have to go. This tends to complicate the whole enterprise. By virtue of adhering to the rules of competition, F1 cars are also compromised in the amount of downforce they actually make.

For all these reasons, Mansell chose to go an entirely different route, instead choosing an open-wheel formula-like car for the job. He selected the Empire Wraith from the world of hillclimb racing, where restrictions on things like weight, horsepower, and aerodynamics are minimal. The Wraith, with significant modification, should be able to generate large amounts of downforce at a much lower speed in order to make driving upside down as easy and safe as possible. In running trim, it typically weighs under 700 pounds, making it perfect for the job.

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To customize the car for the job, Mansell enlisted Willem Toet as his chief aerodynamicist. Toet has an impressive resume, having worked with Ferrari, Bennetton, and Sauber during his career in Formula 1. Drawing on that experience, he has designed an aerodynamic package for the Wraith to help it create double its own weight in downforce at just 80 miles per hour, down from 100 miles per hour in initial estimates.

That figure might sound excessive, but it’s actually around the bare minimum you want for driving upside down. That’s because of how gravity and grip work when you flip your entire frame of reference upside down. For example, when a car without downforce is driving along the ground, it has its own weight pressing its tires into the ground to generate mechanical grip. To generate that same grip when driving upside down, you actually need to generate the entire vehicle’s weight just to overcome the gravitational force pulling the car down, and then actually press the vehicle up to generate grip to that same degree. It’s also obviously desirable to have some safety factor. If, for example, you were generating just barely enough downforce to stick the car to the ceiling of a tunnel, you wouldn’t want a gust of wind or a small bump to cut your downforce and see you falling to the floor.

How To Make It Work

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To achieve maximum downforce at low speed, Toet has reworked the aerodynamic elements of the Wraith design. He put a great emphasis on generating downforce with wings in addition to using ground effect. That choice was due to the fact that the car will be running on a round tunnel surface. In this situation, because the tunnel curves away under the car’s body, the car is effectively running at a much higher ride height than it would be over a typical flat road. This compromises the ground effect aerodynamics moreso than it does the wings.  To that end, Toet designed a huge five-element rear wing, with extra wings either side that pick up the flow over the rear wheels. The front wing is also extremely deep to generate the maximum possible downforce. The design also uses skirts along the side of the body to try and make the most of the ground effect downforce available.

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Cutting the speed down nets huge savings in the cost of the overall stunt. That’s because Mansell is having to construct a tunnel from scratch specifically for this feat. There’s also a safety bonus, too. “It’s much better to have an upside-down crash at 80 miles per hour rather than 150,” Mansell chuckles.

Pregasina Tunnel East Entrance, Pregasina, Trient, Italy
Conventional tunnels are too lumpy to drive on, lack any way to transition on to the ceiling, and are covered in lights and electrical fittings. They’re not suitable for driving upside down. Credit: Lucasbosch, CC BY-SA 4.0

The Tunnel Is A Key Element

In fact, the tunnel is one of the most difficult and expensive parts of the whole thing. The simple fact is that there aren’t really existing tunnels in which you could achieve driving upside down. Even if you could convince a government authority to give you dedicated access to a major road tunnel, you’d need to take it out of commission for months to remove all the lighting and ventilation fixtures on the ceiling. Plus, regular road tunnels tend to have huge bumps and gaps between sections, and just generally aren’t suitable for driving in. Most of all, though, none have been built with a convenient smooth transition for allowing a car to transition from driving on the flat ground, up the walls, and on to the ceiling.

Instead, Mansell tapped engineering agency Expedition Enginering to design an open-sided C-shaped tunnel specifically for purpose. This has the dual benefits of both saving resources and allowing better viewing of the stunt by spectators and cameras. The basic calculations have determined that the tunnel needs to be approximately 2300 feet long to allow Mansell to drive upside down for 5 seconds at 80 miles an hour, and this includes the necessary transitional areas.

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Figuring out the best diameter for the tunnel was more complicated. After an initial pass at the aerodynamics involved, Toet determined that a 54-foot diameter tunnel would be suitable for the task. This was chosen as the larger diameter tunnel would see the surface of the tunnel curve away from the car less underneath, reducing the loss of downforce compared to driving on a flat surface. However, at this enormous size, the tunnel would be very expensive to construct, and present a huge fall if the car happened to come into trouble. Eventually, the team decided on a tunnel 7.5 meters, or 24.6 feet in diameter, which was a good balance between cost and performance. The camber of the car’s wheels also comes into the matter, with a 24.6-foot diameter tunnel requiring the wheels to be mounted at a very significant angle to maintain the best possible contact patch on the curved surface.

As a temporary structure that will only be used on a one-off basis, the engineering team developed a plan to construct the tunnel using something called VarioKit. These are large off-the-shelf building blocks typically used to construct support frames for large building projects like bridges, tunnels, and buildings. Imagine an Erector Set, but at civil engineering scales, and you’re on the right track.

The build rests on concrete sleepers which are to form a solid base for the tunnel and keep it anchored in place. Large water tanks along the back edge of the tunnel will further serve as ballast to weigh the structure down. The red VarioKit C-shaped frames act as the main vertical support structures of the tunnel, with the white steel perlins acting as a subframe to support the road surface tie everything together in the horizontal direction. Four layers of curved plywood will be used to construct the road surface itself, since it can readily be shaped to suit during the construction process. The construction will require a bespoke solution for expansion joints that can help manage the structure’s size change in warming or cooling conditions, which could see the whole structure grow by as much as 15 inches from night to day.Designing The Tunnel For Driving A Formula Car Upside Down 4 25 Screenshot Designing The Tunnel For Driving A Formula Car Upside Down 4 26 Screenshot

Designing The Tunnel For Driving A Formula Car Upside Down 4 22 Screenshot
A great deal of engineering has gone into the project thus far, as these working diagrams demonstrate.

Ultimately, if Mansell is to pull this feat off, he’ll need serious sponsorship to build the car, build the tunnel, and find somewhere big enough to actually do it. The basic engineering is there, though, and all that really remains is to put this madcap plan into action. We can’t wait to see what happens.

Image credits: Driver 61, YouTube screenshots, Tunnel image – Lucasbosch, CC BY-SA 4.0

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Drunken Master Paul
Drunken Master Paul
3 months ago

Every time this come up I have the same thought: “Did I leave my pants at Dennys again?” Quicky followed by: “Can’t you prove this by simply hanging the car upside down in a wind tunnel?” Take said car, put it on a rotating platform, tether the nose to a vertical post so it can’t get blown backwards, add safety straps so it can only move about 6″ off the platform, crank the tunnel up to 120mph and flip the damn thing. That would prove it, wouldn’t it? If it fails it just falls against the straps. If it works it sticks to the inverted platform and the down/up force can be measured.

Autopian project?

Ben
Ben
3 months ago

This feels like a social experiment to find out who has too much money so Danny Ocean knows who to target for his next heist.

DysLexus
DysLexus
3 months ago

“Meh,
Back in the 70’s, my AFX track could turn up side down and still run the formula 1 cars just fine. Didn’t need no funky aero at all”,
Said Magneto von Slotcarski

Thomas Metcalf
Thomas Metcalf
3 months ago

I hope the engine design is such that it won’t get oil starved going upside down.

Steve
Steve
3 months ago
Reply to  Thomas Metcalf

Electric makes sense

Thomas Metcalf
Thomas Metcalf
3 months ago
Reply to  Steve

Or perhaps 2-stroke.

Ron888
Ron888
3 months ago

Wait- someone’s found an actual reason to use stance?

AC2DE
AC2DE
3 months ago
Reply to  Ron888

Afraid so. So much for the “it’s useless” argument…

CSRoad
CSRoad
3 months ago

Project Cactus drives upside down just using available gravity.

Scott
Scott
3 months ago

I’m all for novelty and applied science, but I can’t help but feel it’s a bit of a shame that Mansell and Co. aren’t putting all their effort and expense towards something more practical. Still automotive (of course) but with the potential for real-world utility.

I know, I’m just a curmudgeon.

Clear_prop
Clear_prop
3 months ago

They should check Belfast waste management since the sewer tunnels Top Gear used to loop a car seem like they might be smooth enough.

https://www.youtube.com/watch?v=-TbpgZ2Dt0A

TOSSABL
TOSSABL
3 months ago

I love how inventive humans are.
And my immediate second thought was that will be a very interesting call to his insurance agent.

Bill Garcia
Bill Garcia
3 months ago

Wouldn’t it be possible (maybe even easier because of the reduced weight, risk and insurance cost) to remotely control de car vs having an actual person sitting in it?

To be clear, I have no idea what I’m talking about and not making any suggestions, just wondering.

TOSSABL
TOSSABL
3 months ago
Reply to  Bill Garcia

You know some RC fans started thinking about adding wings and visiting a local concrete culvert. I don’t have any RC cars, but that’s where my mind went reading your comment.

Dennis Ames
Dennis Ames
3 months ago
Reply to  Bill Garcia

But then no “Darwin award” if nothing goes wrong.

Paul B
Paul B
3 months ago

seems to me a scaled down RC car version would make sense as a proof of concept.

Fred Fedurch
Fred Fedurch
3 months ago

An Formula 1? Bennetton?

Proofread. It’s not just for breakfast any more.

Nic Periton
Nic Periton
3 months ago

Serious head on, the tunnel is already here,

https://catesbytunnel.com/

just ask. ( spoiler alert, this place is a teensy weensy likkile bit ‘spensive)

Morgan van Humbeck
Morgan van Humbeck
3 months ago
Reply to  Nic Periton

Doesn’t have a smooth transition from level ground to the walls, is too small, and has fixtures on the roof of the tunnel

Mr Sarcastic
Mr Sarcastic
3 months ago

A few thoughts from the I am not a scientist but I watch them on TV.
1. Does Musks tunnel burrower create a round tunnel?
2. Musk has money and would love the press.a round tunnel would allow a curved front that would solve the higher ride problem caused by a round tunnel. He may even have a test tunnel for use.
3. Not familiar with the chosen vehicle buti was thinking an Atom being light weight and open wheel might work.
4. Pulled it from nowhere a 3 wheel with 1 front wheel might allow a lower wider front wing.
5. What is the minimum hang time to be considered a success.
6. Do wider or thinner tires affect the ability to drive upside down?

Morgan van Humbeck
Morgan van Humbeck
3 months ago
Reply to  Mr Sarcastic

I believe Musk’s tunnels are too small, but that’s a great idea

Mr Sarcastic
Mr Sarcastic
3 months ago

Thanks it was 5 minutes of reading 20 minutes of drinking.

Dalton
Dalton
3 months ago
Reply to  Mr Sarcastic

You’re right, you’re not a scientist.

Sklooner
Sklooner
3 months ago

Im sure this will be shown with the warning ‘closed track professional driver do not attempt’ which would stop me right there even if I had the track all set to go

Morgan van Humbeck
Morgan van Humbeck
3 months ago

I’ve been in communication with Scott about fundraising for this. He’s reticent to try something he’s unfamiliar with. I just got an interview with the MrBeast network, however. Wish me luck, friends!!!!!!!

Last edited 3 months ago by Morgan van Humbeck
Morgan van Humbeck
Morgan van Humbeck
3 months ago

If this goes through, I mean to fundraise for that race track that was going around a few weeks back. The Autopian x Driver61 x MrBeast=the modern streaming version of Top Gear. Let’s gooooo!!!!!!!

Collegiate Autodidact
Collegiate Autodidact
3 months ago

In the penultimate drawing is that…a shark in the water tank?? Ha. Hopefully this won’t turn out to be a case of jumping the shark.

Last edited 3 months ago by Collegiate Autodidact
Mr. Frick
Mr. Frick
3 months ago

There should definitely be sharks in the water tanks! I mean, what’s the whole point if there aren’t? I see a movie tie-in.

Nic Periton
Nic Periton
3 months ago

How many people are able to hold my beer? If I say “hold my beer” to someone already holding a beer how many beers can that someone carry before feeling the need to ask “hold my beer”. Beware beer carrying engibeers, someone is going to end up carrying the can.

Dead Elvis, Inc.
Dead Elvis, Inc.
3 months ago
Reply to  Nic Periton

If I’m going to hold your beer, I’m going to drink your beer.

AC2DE
AC2DE
3 months ago

Call it a storage fee.

Greg Winson
Greg Winson
3 months ago

Well, if they could do it with a 1984 Ford Tempo … https://www.youtube.com/watch?v=OJLUlLA7m6Q

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