If a car is capable of generating more downforce than its weight, it’s capable of driving upside down. But no one has actually attempted this, because with conventional aerodynamic devices—wings, diffusers, etc.—those sorts of downforce levels are only achieved at extremely high speeds. Downforce rises with the square of speed. So building some kind of tunnel to get a car up to necessary speed–and drive upside down—has just been a pipe dream.
The McMurtry Spéirling Pure, a limited-production track-only hypercar, makes its downforce in a different way. Using a fan to essentially suck air out from underneath the car, the Spéirling Pure can generate 4,409 pounds of downforce at 0 MPH—double its curb weight. So, McMurtry built a rig at its UK headquarters to flip a Spéirling Pure prototype upside down, and actually drive it.
I’ll say it again—McMurtry drove a car upside down.
With the fans on and generating maximum downforce, McMurtry’s rig rotated the car upside down while it was sitting stationary. McMurtry co-founder Thomas Yates then drove the car a couple feet forward while upside down. Then the rig turned right-side up so Yates could exit on a ramp, and do a victory burnout. Naturally.
It is one of the most spectacular demonstrations of the effects of aerodynamic downforce we may ever see. Only a fan-car capable of generating this level of downforce could achieve this feat. And it comes as McMurtry announced that it went well under a minute on the Top Gear test track, beating out an old Renault Formula 1 car.
The Spéirling is not the first car to use a fan to create enormous aerodynamic downforce. The Chaparral 2J Can-Am car of 1970 used a snowblower motor-powered fan to create downforce, and Gordon Murray’s Brabham BT46B did something similar in 1978. Murray revived the fan-car concept for the Gordon Murray Automotive T.50 and T.50S track car, but only McMurtry has offered something to the public that offers so much fan-generated aerodynamic load.
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