As the Gordon Murray Mk1 project kicks up a gear (click through to catch up with all our progress to date), we thought it only right to take a look back at some of the great man’s most innovative designs. You know, the cars we most admire, the ones which moved the motorsport (and road car) world on in leaps and bounds, and even a few of those which proved a step too far, too soon. We thought we’d start with one of the best known, the Brabham BT46B – the ‘Fan Car.’
The Brabham BT46B is easily the best known of all Gordon Murray’s design innovations, and this probably owes as much to its Whacky Races-esque appearance as the performance benefits it imparted. Developed at a time of immense upheaval in F1, the fan car was based around a simple concept, namely the idea that an area of low pressure trapped beneath the chassis would enable the car to remain ‘stuck’ to the surface of the track, even whilst cornering at hitherto unheard of speeds.
One of the most commonly overlooked aspects of the fan car’s development stems from its engine, a big, thirsty Alfa Romeo flat-twelve. Not only was it far less efficient that its Cosworth rivals, it was also significantly harder to package and all but impossible to site within the confines of a ‘traditional’ ground effect chassis, its flat-twelve layout leaving no space for the Venturi tunnels utilised by the Lotus 78. The demands placed on him by the the Carlo Chiti designed engine and the need to keep pace with Lotus would eventually lead Gordon Murray to view the problem from a lateral perspective, and it wasn’t long before the wily South African was poring over the FIA’s rulebook with a fine tooth comb.
Said rulebook stated that while movable aerodynamic pieces were legal they would only be permitted if their primary function was something else, something other than a means of gaining downforce. One thing lead to another, and before long Murray had revised the BT46 and fitted it with a massive rear mounted, gearbox driven fan. It was for cooling, naturally; the fact that it was sealed with skirts to create an area of low pressure underneath the car was just a happy coincidence.
It’s worth pointing out that Murray was not the first individual to see the potential benefits of a fan mounted at the back of a race car, the Chaparral 2J of the early ’70s also made use of such a system and proved very effective indeed…until it was banned. Still, it took an engineering mind of Murray’s calibre to see the potential benefits of such a device in F1, and more importantly still, how best to use it without incurring the wrath of the powers that be.
It being a project from the mind of Gordon Murray, the BT46B groaned under the weight of clever engineering and expert packaging – it was no means just a case of slapping a fan onto the back of the car and being done with it. Gordon Murray made sure that the fan itself was driven mechanically via the gearbox, which in practice meant that the amount of downforce it could generate was in way connected to the pace the car itself was travelling it. This would’ve made it even more formidable on tight, twisty circuits, which makes it even more of a pity that the world only got to witness it in action once, at the Swedish Grand Prix of 1978.
The cat was already out of the bag by the time Brabham pitched up at Anderstorp, the press having been passed spy shots of the BT46B and its dustbin lid-covered fan a few weeks previously. This in turn ensured that a storm of controversy greeted Brabham, with the likes of Colin Chapman and Ken Tyrell all moving earth to convince the CSI (FIA today) that the fan car was illegal. It wasn’t, or at least it was legal within the letter of the law, and the FIA had no choice but to allow the cars of Nikki Lauda and John Watson to take part, though both were instructed to drive sedately in qualifying in order to ‘sandbag’ their true pace.
So it was that the pair of BT46Bs lined up in 2nd and 3rd on race day, Lauda leading the charge and just behind the ground effect Lotus 78 of Mario Andretti. Watson spun off early on in the race and took no further part in proceedings, but Lauda, ever the shrewd professional and only too aware of the immense pace advantage he held, waited until Andretti slid wide on a patch of oil. The Austrian drove around the outside of the Italian-American with indecent ease, then cruised to victory without so much as trying. It wasn’t so much a victory as a rout, and Brabham’s rivals were apoplectic.
A week of bitter, acrimonious F1 politicking therefore ensued, the battle made all the more complicated by Bernie Ecclestone’s joint position as boss of both Brabham and FOCA, the Formula One Constructors Association. A deal was eventually reached, one which would have permitted the fan car to race at just 3 more rounds. This would in turn have given the other teams, and in particular erstwhile championship leader Mario Andretti, a fighting chance, and seemed like a fair enough compromise.
It wasn’t to be, the CSI summoning Bernie Ecclestone to a meeting mere hours later to discuss the fate of the car and its ongoing role in F1. There was uproar when the sporting body banned the BT46B on the spot, and this it despite been given the green light mere weeks previously and despite the CSI giving no real reason for its change of heart. Bernie Ecclestone, one eye firmly on the future and the prospect of a position rather higher up the F1 pecking order than a mere team owner, was more inclined to toe the party line than he might otherwise been, and agreed withdraw the car there and then.
It was a muted end to one of F1’s most ambitious projects, and also among Gordon Murray’s most innovative concepts.