30 years ago it was the car supposed to bring Brabham-BMW back in the hunt for the World Championship. It was radical and spectacular. For a moment, it even made Niki Lauda reconsidering his retirement. Gordon Murray’s final work for Brabham certainly had the looks. But it failed to deliver. Read AUTOMOBILSPORT’s protocol about the ‚roller-skate‘ Brabham BT55 and its traumatic Grand Prix season of 1986.
At the end of 1985, Brabham was in turmoil. Since Nelson Piquet had impressively charged to the 1983 World Championship, Bernie Ecclestone’s cars only managed to win three more races. 1985, in particular, was a season to forget. Never short of steam in a straight line, the Brabham-BMW combination had gradually lost its edge in terms of overall performance. Not helped by a switch from Michelin to Pirelli rubber, the team had now fallen back behind McLaren, Ferrari, Lotus and Williams. Even worse, Brabham’s main asset, its Brazilian World Champion driver, had left to join Frank Williams for 1986.
For turning things around, Brabham would need something extraordinary. The task on hand for technical director and chief designer Gordon Murray wasn’t an evolution – he was looking for a revolution. Long before 1985, Murray was well aware of the facts that would limit Brabham’s future potential: „F1 had introduced a new set of technical regulations for 1983, banning the ground effect cars. The dart-shape BT52 fitted that brilliantly to start with, and Nelson won the drivers title. But for any further aero development it was clear that the tall straight-four BMW engine would put us on a disadvantage to the lower and also structurally stiffer V6 powerplants of TAG-Porsche, Renault, Honda and Ferrari.“
The BMW unit wasn’t self-carrying; its installation in the chassis required an aluminium front plate and a steel frame, which gave increased weight and a further handicap regarding packaging on the rear end. Gordon Murray said of the 1985 Brabham: „With the BT54 we had reached the limit of what was aerodynamically possible with the engine concept we had.“
Thinking out of the box
Never one to be afraid of radical approaches, Gordon summarised that there were two major factors that limited his vision on drastic aerodynamic gains: the tall engine and also the upright driver seat position. Regarding the engine, Murray presented the idea of canting-over the BMW motor to his befriended German counterpart, Paul Rosche, early in 1985. Given the dimensions of the straight-four unit this would be the only way to lower the rear end of the car. Rosche liked the idea, but he also draw attention to the high costs of the modifications that the powerplant would need…
by Andreas Riehl
Photographs: BMW, Sutton