BRABHAM BMW BT55

This must be the greatest misunderstanding in the design history of modern Grand Prix racing cars. And the most expensive, too. The theoretical base of the operation BT55 was the fact that the height of the rear wing was limited for safety reasons. To make it more effective it had to be made higher as it had been done at the end of the sixties. Or to take it further backward from the rear axle. Both versions are illegal, of course, because strict regulations are existing to make the sport safer. The only possibility to get more downforce out of the rear wing was to make the car itself lower. The BMW 4-cylinder-turbo-engine was the most powerful unit Grand Prix racing has ever seen. In qualifying there were 1400 horse powers available. But power is nothing without traction. And there were no sophisticated electronics on the market in the middle of the eighties. The grip had to come from the suspensions and, dominating, from the aerodynamics, especially from the rear wing. The BT55 had made 28 centimetres lower than its predecessor BT54 having won one Grand Prix in 1985, the French at Paul Ricard with Nelson Piquet in the cockpit. But after seven seasons with Brabham the Brazilian had decided to leave Motor Racing Developments in August 1985 to join the Williams team. One big advantage of M.R.D. had gone.

To make the BT55 so low a lot of things had to be done by its designer Gordon Murray from South Africa who built the worldchampionship-winning BT49 and BT52. The engine (4 cylinders in a row) was put on the side by Ing. Paul Rosche from BMW to keep the engine cover as flat as possible. The cockpit became extremely narrow and in the prototype version a flat steering wheel like that in the Volkswagen Transporter and only four point seat belts were used (both later had been corrected for practical and legal reasons). The arms and shoulders of the drivers were completely unprotected (see drawing above). The drivers had also problems to breathe, because they had so much pressure on their chest. Only a little roll bar was put over the cockpit to get a better air-flow onto the rear wing.

The effects of the BT55, better traction, more grip and higher speed on the straights only did exist in theory. But the driver did not get such an experience. The BT55 was fast on the long straights. Nothing else. In Monaco Elio de Angelis qualified 20th and last. He was slower than Dr Jonathan Palmer from the small Zakspeed team.

Some days after Monaco Elio de Angelis went testing in Paul Ricard in Southern France to cure the problems of the BT55. But at the fastest part of the circuit the rear wing broke down, the car began to fly before it crashed into the barrier and turned over. The little roll bar collapsed and the wreck caught fire. Elio de Angelis was caught in the cockpit for 8 minutes, because no rescue operation was organized for the case of emergency. He died of a brain bleeding at the 15th May 1986 at 1:00 P.M.

J H

 

Model designation: BT55 Year: 1986 Designer: Gordon Murray Chassis: Brabham carbon fibre monocoque with aluminum honeycomb Engine: BMW 4 cylinder turbocharged Gearbox: Weissmann manual 7 speed Tyres: Pirelli Sponsors: Olivetti, Emporio Armani Drivers: Elio de Angelis/I, Riccardo Patrese/I, Derek Warwick/GB

 

 

 

Drawing: Dipl.Ing. Peter Ruemmler/researchracing

 

 

2000 by researchracing

 

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