Brabham BT 55 (1986): hard core

Brabham BT 55 (1986): hard core

It is the bottom of the stable at the time owned by Bernie Ecclestone, a glorious team that won six world titles, including four Conductors. The BT 55 project turns out to be a failure although the buildings were completely different. The aim of the designer, Gordon Murray of South Africa, was to create a car that returned to the original single seat, which is to have the lowest center of gravity having a high level of road holding, better braking and better overall handling due to less sensitivity to load transfer. And most importantly, open the rear wing to apply power without having to push the weight back. To do this, Murray puts the rider in an almost prone position and It almost completely eliminates physical activity except for the cover of the engine intake ducts. This is due to the fact that BMW produces a four-cylinder engine, which drives Brabhams from the end of 1982, which is left-handed with respect to the direction of travel. Between the design and construction of about thirty engines for this season, the Bavarian company spends 17 billion alarming figure at the time: two teams of engineers, English and German, created 732 technical drawings in 117,000 working hours.
At its presentation in January 1986, the new single-seater from Ecclestone’s team stunned the racing world: it is very low and has decreased, it looks like a car cut in half and without the upper part of the body so that, from the front view, the rear wing is completely visible. It is one of the advantages of the machine, which leaves the air flow that hits it completely free. To get these results, The engine has a good inclination of 72 °, such that the intake box is almost vertical (and is the most prominent feature of the single seat). Another completely novel, hidden, is gearbox: 7-speed Weissman, while others have 5 speeds and one only begins to guess about riding 6. The steering wheel is almost like in a kart (after the first measurements it will be moved closer to vertical), to allow the driver to lie down, whose shoulders are still close. Because of its thinness, the BT 55 was immediately renamed by the public and local people “only”.

With the current rules of the flat bottom

– says Gordon Murray in an interview at the time –

it was very difficult for us to get improvements in ground impact absorption, because our engine has only one turbo and only one exhaust to blow into the rear exhaust. Additionally, the BMW engine is very long compared to the 6 cylinder and this penalizes the efficiency of the rear wing. So I went back to the basic concept of a race car, which is as low as possible

John Barnard supported him: “BT 55 has only advantages – said the new technical director of Ferrari -. Of course, it is a very difficult road, but it includes very smart solutions. There may be problems with the layout of the equipment, with the tuning of the engine, but it may be the trump card”. Barnard was the most fashionable mechanic at the time, author of the first carbon frames for McLaren and the tapered design behind the F1s, imitated by all; in 1989 his Ferrari will set the standard.
The BMW engine is very powerfulbut in general the four cylinder in the turbo era is a less competitive engine compared to the six cylinder, unless special solutions are found. In 1983 Ecclestone discovered fuel injection in the race and the Bavarian engine would remain the only one to boast the name. (but thanks to the special petrol, out of the norm). When refueling was banned in 1984 and the rules set a maximum of 220 liters per GP, things changed. In the same years 1985/86 also Brian Hart, a very talented British engineer but not supported by the official manufacturer, offers his very powerful 4 cylinder engines to Benetton, which replaces the poles traveling at 5 bar of pressure and more, but in the race its engines also explode with reduced turbo pressure to 2/2.5 bar. In short, with the rules of restrictions in terms of consumption (in 1986 the limit was still reduced to 195 liters), 4 cylinder turbos are on the rope (at that time many gasolines were also used to control piston cooling), so whoever installed them had to try to gain competition by inventing original design solutions. And one of the original designers is without a doubt Gordon Murray of Brabham, who tries to deal with the reliability of Honda and Porsche engines with design solutions.. In 1985 the BT 54 had tried to shift the weight as far back as possible in order to have maximum traction, but the only victory would come at the French GP, moreover with great praise from Pirelli tires.