1978 Brabham BT46B “Fan Car”

Fundamentally, the development of the Brabham “fan car” was due to the introduction of the Lotus 79, and in a sense the latter part of the Lotus 78. Both of those cars were essentially ground-effect cars with sliding skirts. The initial concept of the Brabham BT46 was to have surface-cooling through panels on the sidepods. This was one reason, not in totality but in part, the car had a triangular shape, whereas its predecessor, the BT45, had gone away from that shape and was designed along the lines of a somewhat more conventional car. Gordon Murray, the Brabham designer, had come up with a concept that in theory was totally brilliant. I drove the car in its surface-cooling configuration; what it did was reduce the drag of a conventional radiator, with a result much like having an extra 100hp. It was phenomenal. The problem was the cooling surface was far too inadequate for the amount of heat produced by the engine, thus making the panels inefficient.

The problem left us with a somewhat radical and unconventional car that had to be conventionalized. It also meant the car we had worked on for the forthcoming season was now irrelevant. Something had to be done, and quickly. The only answer to address our cooling problems, for the interim, was to revert to the more conventional twin radiators at the front of the car like the BT44 or the BT45. The Alfa Romeo boxer engine ruled out the use of venturi sidepods and left us seeking an alternative solution. We realized that our flat-12 engine in a slab-sided chassis that was quite wide underneath wasn’t going to work when the Lotus 79 appeared at the 1978 Belgian GP at Zolder. Gordon, being a very brilliant designer and a very lateral thinker, looked at the problem. They say there’s nothing new in life, so, he looked at what Jim Hall had previously done with the Chaparral in usting a fan to create a low-pressure area underneath. It was, nonetheless, quite a revolutionary design for a Formula One car. He went to work on it and both the team and Alfa Romeo, our engine partner, produced extra parts to allow a fan to be positioned at the rear of the car with a radiator installed on top of the engine. The engine bay itself was sealed, which created a partial vacuum when the car was in motion. It’s far more technical than that, but that is essentially what we ended up with. It also allowed us to revert to the very slim front nose as used initially on the surface-cooled car. In reality it produced a gear-, or rather an engine speed-driven fan. In turn it provided us with both cooling and road-holding capacities. When driving the car, if the speed dipped the car would lift its ride height and, conversely, the more speed the closer to the ground it went.

The development of this was very quick, just a matter of weeks. The advantage we had over a conventional ground-effect car was, because it was geared to engine speed, if the car was at 12,000rpm in first gear it would give the same amount of suction as 12,000 in 6th gear. When we ran it in Sweden, we had a further advantage in the medium-speed corners that made up the Anderstorp circuit; whereas the Lotus was dependent on road speed for grip, we had the grip through the engine revs. Consequently, we were able to take these corners at a much higher speed than the “wing” car. Of course, while the engine would give us three-quarters or even seven-eighths of the total downforce, it was augmented with more traditional aero loading from the front and rear wings.

In a driving sense, the car was quite different too. As I’ve already mentioned, as the engine speed increased so did the downforce, as opposed to the relatively conventional Lotus 79 relying purely on road speed. A driver needs to get a balance on a car, meaning when the car increases in speed the balance, front to rear, remains the same. It was quite difficult to maintain equilibrium when the downforce was coming from both the mechanical grip generated by the speed of the fan and the aerodynamic grip from the wings. Don’t forget that both forms of downforce were reliant on different parameters of engine speed and road speed. Test driving the car was quite difficult for Niki Lauda and me. I remember we had only a couple of outings at Brands Hatch and the preliminary runs with all the other teams prior to the Swedish GP at Anderstorp. Don’t forget, the whole project was shrouded in immense secrecy. As most are aware it is very difficult, in motor racing terms, to keep anything secret.

When we took to the circuit at Anderstorp, we had a load of what I would describe as “bollocks” from both Mario Andretti and Colin Chapman about the car throwing up debris from the track. In essence they were both pissed off that Gordon had quickly reversed the advantage of the Lotus 79 wing car that had given Andretti victories in the previous two Grands Prix in Belgium and Spain. They did what I refer to as a Jeffrey Archer—they lied through their back teeth. They knew that the Brabham would rob them of further victories and, more importantly, the 1978 Constructors Championship. Not only that, other teams in the pit lane, notably McLaren and Tyrrell, would follow the Brabham concept. This would spark an uncontrolled technical frenzy with people designing a fan car that would shortcut the process of generating ground effect. There was a danger that everything would suddenly escalate and technology and chassis design would not keep up with the potential. It would mark the entry into another frightening period in the development of the racing car.

One of the statements made about the Brabham BT46B fan car is that it was banned after the race. Let me tell you that’s not true—it was never banned. The car was voluntarily withdrawn from competition by Bernie Ecclestone. A deal was struck, prior to the start of the Swedish GP, between Bernie and the other constructors. The Brabham team had arrived at Anderstorp with just the fan cars, and it was argued that the cars could not be reassembled into more conventional racing cars prior to the Grand Prix. So, the deal was to let the cars race in the “fan” configuration and let the result—whatever it would be—stand. Following the race, the car would not be entered again with the fan—the so called “banned” element. Qualifying left me and Niki on the second and third spots of the grid, respectively, behind Mario Andretti. For the race, I had problems with a sticking throttle and retired on lap 20. At the front an epic battle ensued between Niki and Andretti. Niki made the most of a driving error by Andretti and passed him. Despite trying to fight back, Andretti’s car developed an engine problem and he retired. Niki’s winning margin was over 30 seconds—such was the performance of the car.

Personally speaking, I think it was probably right to take the action we did. There was a considerable danger of entering a field of design and technology that no one really understood. The wing and aerodynamic concepts of the late 1960s had proved very difficult in the initial stages, with the first high wings supported by fragile struts. They were subsequently banned after a series of serious crashes. As could been seen from Gordon’s work, the progress of such technology would have been very rapid. Safety would have been compromised. Let’s not forget we hadn’t yet entered the carbon fiber era, and tubs were becoming very skinny. The potential of raising the cornering speeds, or G-force, to say, 2.5 to 5G—which was a very great possibility—would have been quite alarming considering the fragile construction of the chassis. I could foresee another period of serious accidents and severe mechanical failures as we didn’t have the ability on a technical level to support the concept of the fan. It would have been a leap too far and, fortunately, common sense ruled. The consequence to this action meant that Mario Andretti and Lotus took the championship, although Niki did take a further victory at Monza (following penalties issued to Andretti and Villeneuve) for us in the BT46 in its C spec, which retained its slim nose and new radiators positioned behind the front wheels. It was Alfa Romeo’s last Grand Prix win (to date) but a somber victory with the loss of Ronnie Peterson. Despite the upheavals of the season, the team worked hard to overcome these issues and ended up with a well-deserved 3rd place in the championship with ten podiums.

As told to Mike Jiggle