First car to park and technically drive upside-down using downforce

Downforce is a hell of a drug.

Scott Mansell (Driver61 on YouTube) has been working on a project to do this with conventional aero on a crazy inverted track for a while, but it seems to have stalled lately. Which I suppose is not surprising since it's complicated, expensive and dangerous. But I'd love to see it done at some point. It's just such an audacious display of physics.

In reply to JG Pasterjak :

Yeah he gave up on that a while ago because of the enormous expense of building the track, and the danger of driving upside-down at a healthy speed dozens of feet off the ground held up only by downforce.

The only way the track for such a stunt will get built is for a megacorporation with a huge PR budget or an "eccentric" billionaire to throw money at it for E36 M3s n' giggles, or maybe if some day a new track gets built with a tunnel section, the tunnel might happen to be designed with this idea in mind...

They can get rid of the wing now and shape the car like a bullet.

I wonder if  "Downforce on Demand" is tuned to add suction by the amount of steering lock for cornering and dials it back on a straight.

In reply to j_tso :

The car has all the sensors needed to do it, it's just a matter of software...

Last I checked they have an issue where the car can generate levels of downforce that can rapidly obliterate the tires (even though they're custom-made for the car), such that any suction fan setting over 70% should only be used for accel/decel tests. So with tire life/integrity being the bottleneck, the only advantage to dialing it back on the straights might be maximizing power to the drive motors and reducing heat buildup in the batteries. If there were any tires that could take more abuse, then they could adjust downforce to suit the need for traction, which I think would be just maxing it out in corners and braking zones and having it taper off when on the "gas" in a straight line at higher speeds.

I don't think this really qualifies as "it can drive upside down", at least not in the way it's usually said about F1 cars.  The force holding it there comes from a fan, rather than from wings in the forward airstream.

I'd say it's more of a helicopter in, uh... "ceiling effect". :)

GameboyRMH said:

So with tire life/integrity being the bottleneck, the only advantage to dialing it back on the straights might be maximizing power to the drive motors and reducing heat buildup in the batteries.

Too much suction would also be holding it back from achieving a higher speed because downforce is also drag.

Like how WEC cars have a lower downforce configuration for Le Mans.

Equally impressive to me is the fan setup.  How does that work???

jfryjfry said:

Equally impressive to me is the fan setup.  How does that work???

The underside is divided into 2 chambers, each has its own electric fan providing suction and has its own seals against the ground, so if a fan stops working or a chamber loses its seal with the ground, only half the downforce is lost.

j_tso said:

Too much suction would also be holding it back from achieving a higher speed because downforce is also drag.

Like how WEC cars have a lower downforce configuration for Le Mans.

While that's true, the lift/drag efficiency of different aero devices can differ widely.  I don't know how much drag a "sucker car" fan makes compared to a wing or diffuser or whatever.

Technically it's being held up by the air below it..  

It's a neat demonstration for sure.  Didn't Dyson or oreck do something similar using suction created by their vacuums to lift unusually heavy objects?

Driver61 needs to build a similar rig with a treadmill that is pushed along.  Then flip the platform over.  He could demonstrate actual aero downforce at speed for probably under $100k.  Plus the car could be tethered to the rig for safety.  

In reply to nocones :

Remember the barrel roll car jump from James Bond? Just join the two ramps with a long flat topped tube or a couple of trusses and an upside down road/bridge.

Hagerty.com: Astro Spiral: Revisiting the greatest car stunt of all time

So what happens when you actually go past the limits in one of these and find a gravel trap? Is there a rooster tail of gravel out the back until all the fan blades are shredded off? I bet that makes a fun noise

nocones said:

Driver61 needs to build a similar rig with a treadmill that is pushed along.  Then flip the platform over.  He could demonstrate actual aero downforce at speed for probably under $100k.  Plus the car could be tethered to the rig for safety.  

Or, do a demo with their car on a flip rig in a wind tunnel. Not as thrilling as doing it while moving, but it's actually doable and would show the same principles.

adam525i said:

So what happens when you actually go past the limits in one of these and find a gravel trap? Is there a rooster tail of gravel out the back until all the fan blades are shredded off? I bet that makes a fun noise

There is some sort of grate or filter to catch bigger pieces of gravel, but dust and smaller bits do go through the fan blades and wear them out.

When driving upside down its using upforce, not downforce.