4 hours Ago By Matt Somerfield
F1 is celebrating its 75th year and during that time we’ve seen all sorts of weird and wonderful solutions used by the teams as they poke and prod at the regulations to find performance. However, one solution might stand head and shoulders above the rest, with an almost mythical status bestowed upon it by virtue of the crushing victory it delivered only for it to be retired after that race. I am, of course, referring to the Brabham BT46B or, as you might know it, the fan car.
And, whilst it might seem whacky, it was a solution born out of necessity, as the flat-12 Alfa Romeo engine that powered their car prevented them from having the winged underbody ‘ground effect’ tunnels that had led to Lotus becoming the dominant force in 1978. The Lotus 79, or ‘Black Beauty’, as it was referred to at the time, was head and shoulders above the rest of the field but only by virtue of the development that had been done with the car’s predecessor, for which results had been lacking. This had kept much of the development work that Lotus had been doing off their rivals’ radar though, meaning they hadn’t really cottoned onto the Lotus 78’s underlying potential, so much so that when the ‘79 arrived they were all too late and simply left playing catch up.
Meanwhile, over at Brabham they’d been looking for their own leap forward, as the BT46 emerged with a revolutionary heat exchanger setup, rather than the conventional water and oil radiators ordinarily employed. Just like everyone else in this time period they were looking for the upper hand on their rivals and thought this would offer a way to save a considerable amount of weight and clean up the cars aerodynamic profile. However, the team had to concede that the ‘surface cooling’ panels laid out on the slanted sidepod bodywork simply didn’t provide sufficient cooling and the BT46 would have to be redesigned.
As such, a more conventional, front mounted radiator arrangement like the car’s predecessors had utilized was fashioned onto the BT46. Meanwhile, stacked atop the engine, more radiators littered the ‘46’s previously untarnished rear end. Brabham’s chief designer, Gordon Murray who had toyed with V-shaped airdams in previous seasons to create a localized low pressure region soon worked out that the ‘79 appeared to be using their full length skirts with the sidepod underwings to create a similar effect, just with much more potential.
Knowing the limitations posed by their engine configuration, he knew that the team had to find another solution and perhaps looked for inspiration elsewhere, with the Chaparral 2J, also known as the ‘sucker car’ usually cited as a possible muse, given it’s another fan driven machine, albeit a sports car, using skirts to create negative pressure under the car. However, there’s also a rumour that Tyrrell had got there before Brabham and tested a fan solution on their 008. The project was reportedly shelved after the test though, as the team realised that they would need to do some serious work to make it race ready and thought they’d be better off improving other aspects of their car.
No matter where the idea came from, Brabham still had numerous hurdles they’d have to overcome, with the fan’s installation contingent on it supplying over 50% of the cooling required by the radiators. This led to the radiators being removed from the front wing again and placed on the deck above the engine instead, where they could be fed by cool air being pulled through the car by the fan at the rear. The surplus created by the fan was still more than enough to create the aerodynamic forces asked of it though, with further changes made to the underfloor and hinged skirts added that would fold up as the car was sucked to the ground, a phenomenon that could be seen when the car would squat as the driver blipped the throttle.
Given the counterintuitive nature of the cars behaviour, the driver would need to add throttle during cornering to increase the fan speed and maintain downforce rather than lift out of the throttle. This led to a pitot tube being mounted on the car’s nose whilst an altimeter was rigged-up in the 46B’s cockpit and on corner entry the driver would monitor the gauge and accelerate if the gauge was in the green and would know he had to slow if it was in the red, as a skirt had failed. Prior to its arrival at the Swedish Grand Prix, word had spread of what Brabham had been working on, with the team having put the car through its paces in several tests, including at Brands Hatch.
During these tests it was discovered that the fan blades would need to be more robust, going through several different material choices before landing on an Aluminium arrangement that was readied just before the race at Anderstop. Nonetheless, efforts were made to disguise the fan from the prying eyes of their rivals, albeit there was no custom solution like you’d expect if this were to happen today, the mechanics simply placed a dustbin lid over the fan’s assembly as it was conveniently sized. As soon as the car hit the track it was apparent how quick the BT46B was, leaving the rest of the teams outraged and set to lobby the governing body for its removal from the event.
But, having done his due diligence ahead of time, Murray was certain that they would uphold its inclusion. Meanwhile, Brabham’s owner, a certain Mr Bernie Ecclestone and chief executive of FOCA had a rather difficult balancing act on his hands. Worried about the sheer speed of the BT46B he ordered his drivers to qualify on full tanks, use the hardest compound of tyre and deliberately under drive their cars, so as not to show their true pace.
Regardless of their tactics, it was still clear to see how quick the BT46B was and given they’d failed to have the car removed from the event on a technical front, the drivers began making remarks about safety. They used a similar approach to the one used to remove the Chapparral 2J from competition, suggesting dirt and debris was being flung up from the rear of the car. It was to no avail though and the BT46B, helmed by Niki Lauda would overtake Mario Andretti in his Lotus 79 en-route to victory.
Murray’s ingenuity might have beaten the rule book on this occasion but it was to be short lived, as Ecclestone decided to withdraw the car from future events, as he couldn’t risk destabilising FOCA. This is why the BT46B ‘fan car’ holds a mythical status in Formula One, as to this day it remains the only Formula One entrant with a 100% win record..
