It’s 1978 and Formula One racing is being dominated by the Lotus 79 and its pioneering ground effects. Gordon Murray, at that time was designing grand prix cars for Brabham, and figured out Lotus’s secret, but couldn’t replicate it for the BT76 because its flat 12 Alfa Romeo engine didn’t allow space for the necessary venturi tunnels. Instead, inspired by the Chapparal from sports car racing and taking advantage of a loophole in F1 regulations, he added a fan to the back of the BT46, creating the BT46B.
The rules say that no moving parts can be added to the car primarily for aerodynamic advantage. He could, therefore, argue that the fan is for cooling the engine and the downforce is a side effect. Naturally, the other teams objected to this slightly creative interpretation of the rules – and particularly Lotus boss Colin Chapman and driver Mario Andretti.
To try to disguise the BT46B’s advantage, then Brabham boss Bernie Ecclestone instructs the drivers to qualify with full tanks of fuel. Furthermore, when the car is stationary in the pits, a dustbin lid is used to hide the fan. But the BT46B is dominant at its debut at the Andertstorp GP in Sweden, and the other teams complain vehemently.
The authorities allowed the BT46 three more races before the fan has to be removed, but Bernie played a political game and had the fans removed from the cars before the next race. So Andersorp is the only race that the Fan Car, as it was nicknamed, competed in. In this video, we ride on board with Andretti in his Lotus 72 that very weekend, and try to dodge the dirt and stones he accused the BT46B of throwing onto following cars…