Fans as aerodynamic devices go back to 1970 and the extreme Can Am racing series

In 1992, McLaren debuted the F1, by far the most innovative production car of its era. Designed by Gordon Murray, the F1 needed less than 30 years to become a full-fledged classic, and it’s regarded as one of the greatest supercars ever built. It’s 2020, and Murray made a spectacular comeback with the T.50, a supercar developed and built by his own company, Gordon Murray Automotive (GMA). A spiritual successor to the F1, the T.50 also features a naturally aspirated V-12 engine, carbon-fiber construction, and three-seat layout, but it incorporates even more groundbreaking technologies. Among them, there’s a rear-mounted fan that helps to create downforce, thus eliminating the need for a massive wing out back. And this specific feature reminds me of two iconic "sucker cars" from the past, namely the Chaparral 2J and the Brabham BT46.

How does the Gordon Murray T.50’s fan work?

The Gordon Murray T.50's Rear Fan Revives Technology Used By Radical F1 and Can Am Race Cars Exterior High Resolution Wallpaper quality
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The 15.7-inch fan is mounted in the central, upper section of the rear fascia and works as a ground-effect device in conjunction with underbody aerodynamics and two dynamic spoilers.

The fan rapidly accelerates air passing under the car and forces it through active control ducts in the diffuser. It manages both underbody and overbody airflow, balancing drag and downforce at all speeds. Powered by a 48-volt motor, it spins at up to 7,000 rpm and eliminates the need for a rear wing or spoiler.

This aero system has six operating modes, two of which are automatic. In the default Auto setting, the car operates with passive ground-effect downforce, while Braking mode activates the fan to improve stability and improve braking power. The fan itself can shorten the braking distance from 150 mph to a full stop by almost 33 feet.

The Gordon Murray T.50's Rear Fan Revives Technology Used By Radical F1 and Can Am Race Cars Exterior High Resolution Wallpaper quality
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In High Downforce mode, a driver-selectable function, the fan spools up and helps increase downforce by 50 percent.

Streamline mode sets the fan to operate at high speed in order to draw air from the top deck to minimize drag while extending the trailing wake of the car to create a virtual longtail. This mode cuts drag by 12.5 percent, boosting straight-line speed and reducing fuel consumption.

Finally, there’s V-Max Boost, a more extreme setup that uses the 48-volt system to power the fan, freeing up power to the driveshaft. When this happens, and combined with ram-air induction, the T.50 output jumps from 650 to 690 horsepower.

A similar system was used on the McLaren F1 too

1993 McLaren F1 Exterior
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The F1 came with so many groundbreaking features that its fan system is usually overlooked. McLaren’s supercar had a similar setup, with two fans hidden beneath each of the F1’s rear haunches. Just like on the T.50, these fans pulled air from under the car to improve downforce, making the F1 the first road car to employ such a solution.

The sucker fan design goes back to the late 1970s

Murray’s fan system is far from new. Gordon actually designed something similar back in the 1970s, while working with Formula One racing team Brabham. Called the BT46B, the "fan car" was introduced during the 1978 season in response to the dominant ground-effect Lotus 79. The BT46B was an unusual appearance because it featured a massive fan in the rear. Movable aerodynamic devices were banned back then, but Brabham found a legal loophole by arguing that the fan’s primary purpose was cooling. But the fan was, in fact, generating an immense amount of downforce by sucking air from under the car.

The car debuted at the 1978 Swedish Grand Prix and won its maiden race with Niki Lauda behind the wheel. The other teams immediately saw the BT46B as a threat to their competitiveness, and the Formula One Constructors’ Association (FOCA), led by Lotus chief Colin Chapman, pressured Brabham boss Bernie Ecclestone to withdraw the car. In 1978, Ecclestone had also become the chief executive of FOCA and decided to discontinue the BT46B over fears that he will lose support from the other teams. Although Ecclestone negotiated a deal for the car to race another three events before being withdrawn, the Commission Sportive Internationale banned fan cars altogether before the BT46B was able to race again.

Although the connection between the Brabham BT46B and the T.50 is obvious, Murray says the systems aren't related at all.

"The way it works has got nothing; it owes nothing to the 46B. Because, you know, the 46B was just a crude instrument. It was literally just peripheral skirts and a fan designed for suction. It was an awfully crude device. This is much more sophisticated. This system is called ’boundary layer control,’ and it owes more to aircraft," he told Jalopnik.

The first "sucker" car was actually raced in 1970

Murray may have designed the first Formula One and the first production car with a fan, but this solution was first introduced by Chaparral Cars, a Texas-based racing outfit that built a few experimental Can Am racers through the 1960s. Chaparral introduced its fan car, the 2J, for the 1970 season, and it looked decidedly unusual. Featuring a flat body with a boxy rear end, the 2J employed two fans in the rear and articulated plastic skirts that sealed the body against the ground. The latter also inspired Lotus to build its first ground-effect Formula One car.

The skirts enable the fans to create a vacuum under the car, which produced more downforce than a rear wing, increasing grip and improving agility at all speeds. And because the system created the same levels of low pressure under the car at all speeds, downforce did not decrease at lower speeds, something that competing cars didn’t benefit from. Although it failed to win races due to mechanical problems, the 2J qualified at least two seconds quicker than the next faster car at every event. The car was banned by the Sports Car Club of America at the end of the 1970s due to pressure from other teams who argued that the fans were movable aerodynamic devices that weren’t allowed in Can Am. The Chaparral 2J’s fate was pretty much similar to that of the Brabham BT46B.

Ciprian Florea
Senior Editor and Supercar Expert - ciprian@topspeed.com
Ciprian's passion for everything with four wheels (and more) started back when he was just a little boy, and the Lamborghini Countach was still the coolest car poster you could hang on your wall. Ciprian's career as a journalist began long before earning a Bachelor's degree, but it was only after graduating that his love for cars became a profession.  Read More
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