This Vacuum-Effect RC Car Would Make Gordon Murray Proud

Watch as this YouTuber builds an RC car with a vacuum ground effect similar to the iconic Brabham BT46B.

byNico DeMattia|
Culture photo

In 1978, the Brabham Formula 1 team made history with its legendary “fan car.” Then-Chief Designer Gordon Murray (the father of the McLaren F1) designed the BT46B F1 race car, which featured a large fan and ground effect skirts to generate low pressure underneath the car, essentially creating a vacuum that sucked it onto the pavement. It was revolutionary and controversial but, more importantly, it was fast. YouTuber ProjectAir recently decided to use that same effect but on an RC car—and the results aren't only pretty cool, but also highly entertaining.

The host, James Whomsley, drew inspiration from Murray’s famous fan car for the latest of his popular, aero-focused RC builds. He bought two identical RC cars; one to mod and one to leave stock for comparison’s sake, and quickly began rigging one for fan-car duty. 

At first, he designed a small vacuum floor to be fitted horizontally underneath the car, which extended out to the width of the wheel track on either side. He then fitted two fans to that floor, which would essentially suck the air out from underneath the car, thus creating the low pressure needed for maximum downforce. However, as he eventually found out through various rounds of testing, the horizontal floor proved to be too small of an area for the low pressure to work.

That’s when Whomsley redesigned the floor to fit longitudinally underneath the car, providing the largest ground effect area possible. Additionally, rather than two small fans, he fit one much larger fan to the back, truly channeling Murray’s BT46B fan car. This single-fan setup was so much more effective, that the RC car could actually stick itself to a surface upside down and hold its own weight. With the new floor and a functioning skirt in place, he brought both the modded car and the stock car to a warehouse to test them both out.

On the slippery, polished floor of the warehouse, the stock car struggled for grip, both understeering and oversteering unpredictably. The fan car, though, had far more grip and was significantly easier to control. There was one downside to having a rolling vacuum, however, as once its protective screen filled with debris from the floor, the fan stopped functioning properly and the car began to understeer, again proving just how effective the fan was when functioning properly. 

During a slalom test, Whomsley noticed that adjusting the fan strength made a big difference to the speed of the car. A balance needed to be found between the downforce from the fan and the drag of the skirt, for optimum speed. 

Lastly, he took both cars outside, on a circular track, to test them out on the actual tarmac and both hilarity and tragedy ensued. There's no doubt Whomsley is on the right track to creating something extremely cool, though as we witnessed in this video, it will likely take lots of tinkering to perfect it.

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