In Laymen's Terms: Flipping the Bird

"KylesPerGallon" (gentlemandriver)
05/06/2015 at 18:00 • Filed to: ILT, In Laymens Terms, Downforce

Why no one has driven a car upside down, yet...

Wait? Schumacher didn’t actually do this already? Nope, that was just a !!!error: Indecipherable SUB-paragraph formatting!!! Mercedes quickly threw together. It also looked fake as hell and we didn’t care because ze Germans were just excited to get their golden boy Schumi zuruck back from his lengthy loan to the Italians. Besides even with their CGI commercial they didn’t even attempt to portray the vaulted ‘upside-down car’. Because if we’re being honest a barrel roll isn’t far removed from the loop-de-loops that we did with matchbox cars as a kid, and that doesn’t quite make us want to get out of bed. The read deal is more complicated than that.

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Falling With Style

The proof is in the proverbial negative-g pudding and that means getting a car going so fast its aero bits stick it to the ceiling. ‘In Laymens Terms’ [ILT] is a breakdown of some seemingly complex physics related situation into a more consumable form. Today we’re looking at aero, the go fasty bits that help push cars to the ground (and maybe one day to the ceiling). After all that’s what Formula 1 teams are after with all their wind tunnel testing. The majority of performance gains in the top level of motor racing is due to their ‘aero package’ which will determine weither you can spray girls in the face with champagne or wind up as fodder in the Madonado Cannon.

Downforce is the primary goal in vehicular aerodynamics. The opposite is quite horrifying and we’ve seen it multiple times in racing when the car has a mid-race crisis and decides it always wanted to be a plane instead. So is downforce a pushing or a pulling force? Pushing. Glad we got that out of the way, kinda. Essentially the easiset way to wrap you head around air pressue and forces related to air pressue is to think about you, a human being, standing in the middle of a field. When you look straight up to the sky theres a few miles of air molecules over top of your head. While these individual molecules of oxygen and nitrogen don’t weigh much on their own the combined weight of an entire column going up to the edge of the atmosphere is a

considerable amount. So much in fact that it would crush you to death. Thankfully this doesn’t happen because there’s pressure below you pushing up against this force. In fact you feel this pressure in all directions. In racing we try to direct this force in a specific direction. By doing so, you can theoretically drive upside down provided you have the right equipment. Namely a massive pair between your legs.

Downforce, what your civic lacks.

Modern F1 cars and other high level prototype vehicles create downforce by use of an airfoil (ILT:wings) and diffusers. The purpose of both of these devices is to create less pressue underneath the car than on top. Lift is achieved in airplanes via the reverse formula. Remember that column of air? Well now we’re taking away some of its balancing force. That’s pretty much the size of it. By having less pressure under the car the force pushing up keeping it from being crushed is lessened therefor the air above the vehicle (regardless of orientation) will push harder than the air below the vehicle. In something with aerodynamics like an F1 car this force is greater than the weight of the vehicle at higher speeds and thus you can now defy gravity. That’s it no smoke and mirrors, hocus pocus, or voodoo here.

It’s not a myth and its not just a hypothesis. How can I be so sure? Because if I’m wrong than Boeing is a multi-billion dollar company operated on witchcraft.

I can hear you asking now, ‘why has no one ever attempted this if it’s such a sure thing’. Well the simple answer is that the only vehicles currently capible of performance such a feat have to be extremely powerful to achieve the speeds required to to produce a greater downforce than the pull of gravity. So no, your twin turbo SRT Neon won’t be reenacting the scene from Men In Black. Secondly, it also needs to be a featherweight, and that means carbon fiber and lots of it. If you’re following those two requirements there should be one very obvious third problem, $$. Yes money, F1 cars don’t come cheap. These are multi-million dollar vehicles and dropping one on its intake would surely be a write off when the claims adjuster shows up. That and there’s also the pink fleshy bit that sits in the thing that needs to sign up for this crazy stunt. That’s a lot of obsticles in the way of pulling this off. So unless Elon Musk decides tomorrow that he want’s to blow a lot of cash pulling off the worlds most elaborate and meaningless stunt it will continue to remain unconfirmed for the time being. Seriously though, do it Elon.

...because I was inverted.

All is not lost however, a quick google search does yeild some interesting results for ‘upside down car’. While a LeMons camaro isn’t quite what we’re looking for all is not lost. A lot of calculations have been done by people who want to put a lot more time and effort into the discussion than me. But using some rudimentary maths, I’ve put together the budget way of pulling this off. Essentially we need a tubeular frame for holding all the bits on and keeping the driver from being turned into road seasoning. Next bolt in a second hand LS motor and to it attach a pair of turbos. This should be able to push things north of 1000 horsepower, if only for just a couple runs. Then comes the really involved bit. You need to design an aero package consisting of a front and rear wing element whose top speed (drag limited) is faster than the point where the wings produce more downfoce than the weight of the car. If you think back to your physics class, our favorite formula F=m*a . For the car, the force is equal to its mass multiplied by gravity. If the pressue on these wings at speed is greater than the product of the cars mass times gravity than voila, you can now achieve upside down driving. The rest of the complexity lies in finding a tunnel owner willing to let you perform this endevor, building a ramp of sorts to allow for a smooth transition from 0 to the 180 degree mark, then the engine must be modified to keep all the critical parts lubricated while inverted.

Now does anyone know someone with a tunnel?

In Laymen’s Terms is a series of articles to help illustrate physics and technology related conundrums in a satirical manner. I’m not trying to belittle your intelligence. I’m assured it’s very large.