For the 1978 Formula 1 season, the Brabham BT46 is a Formula 1 designed racecar for the Brabham team of Bernie Ecclestone by Gordon Murray. The fan car had many innovative concept features, including heat exchangers with panel flats on the car bodies to replace traditional radiators with water and oil. When consultant engineer David Cox saw pictures of the vehicle, he determined that the BT46 needed just about 30% of the cooling surface.

At the 1978 Swedish Grand Prix, in response to the Lotus 79 dominant ground impact, the “B” version of the car, also known as the “fan car,” was unveiled. The BT46B produced a considerable amount of downforce through a fan, claimed for improved refrigeration, but also removed air from under the engine. The car was not raced until Niki Lauda took the 1978 Swedish Grand Prix in Anderstorp in the Formula One World Championship.


An article in Autosport by former journalist John Bolster some months after the retirement of the vehicle’s fan car told the history in-depth and gave David Cox credit for much of the design and its implementation. Cox explained how the layout in his mind was evolved, numerous computations involved in it were taken, his position in finding the legal loophole, and the approved compliance of a vehicle with the regulations obtained from the delegate of the governing body.

Brabham withdrew the “fan car” idea after a rally, despite FIA’s ruling that it should be used for the rest of the season. Car designer Gordon Murray later said that Brabham had pulled off the car because of complaints from the team owner Bernie Ecclestone. In the same year as the Brabham BT46, Ecclestone became Charge Executive of the FOCA, who was worried that the upheaval of other teams on the fan car would crash with FOCA. In 2008, Murray said Ecclestone was working on the Formula One Manufacturers’ Association.

Amendments to the fan car concept included the sealing of the engine bay, the clutch mechanism, and the fan. The fan car concept was also comprehensive. In some secrecy, they were planned and tested. Niki Lauda, Brabham’s primary driver, realized that he had to change his driving style, mainly to corner. He noticed the car would “stick” to the ground as though he were on rails if he were accelerating around corners. The result was that the driver was subjected to high lateral accelerations, which became a big issue in the age of the field-effect.