X-ray spec: Brabham BT52 – Gordon Murray's 5min F1 wonder

Gordon Murray's rush job: and it wasn't just the car that was wired, he tells Keith Howard

3 1983 Brazilian GP Brabham Nelson Piquet

Simplistic approach proved frutiful with Brabham BT52

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For some, like Cosworth’s Keith Duckworth, Formula 1’s turbo era was a crazy aberration. When F1 ‘s return to power had arrived in 1966, the rules included a provision for 1.5-litre forced-induction engines, the intention being to ease the transition to the new 3-litre normally-aspirated formula. Nobody exploited it at the time, but inexplicably it remained in the regulations until the temptation to seize on the ridiculous equivalence it enshrined became too great.

By the early 1980s the all-but-ubiquitous Cosworth DFV generated less than 500bhp. With its blown 1.5-litre M12/13 engine and trick fuel, BMW would achieve something over 1400bhp in qualifying trim during 1983 in the back of the Brabham BT52. Even Paul Rosche didn’t know exactly how much power his four-pot made — it outstretched BMW’s dyno.

Renault had pioneered the turbo in F1, and ’83 was supposed to be the year it struck paydirt. The team was widely expected to win the constructors’ championship, and Alain Prost his first drivers’ title. But others on the grid were reading from a different script. In a three-way tussle with Ferrari and Brabham, the French team came away with nothing. Ferrari clinched the constructors’ title by 10 points and Nelson Piquet pipped Prost by a mere two. Brabham might have taken the constructors’ gong too, but for a grim year for Piquet’s team-mate Riccardo Patrese, who amassed a mere 13 points to the Brazilian’s 59.

Riccardo Patrese Brabham 1983 British GP

Brabham could have clinched ’83 constructors’ crown were it not for Patrese’s paltry points haul

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Gordon Murray’s BT52, which he talks about here, tends to be remembered principally for its fire-breathing BMW powerplant and the sour controversy that Renault kicked up over the engine and its fuel. FIA tests confirmed that both were perfectly legal but, as usual, when mud is being slung some of it sticks.

In fact the BT52 was remarkable for much more than being strapped to Munich’s ‘grenade’. At a time when an alarming hike in engine power was accompanied by major aerodynamic rule changes intended to take a large bite out of the downforce generated by ground effect, Murray — despite enormous time pressures — incorporated a number of significant design innovations. He also took the bold decision to eschew wind-tunnel testing, move as much weight to the rear of the car as possible to aid traction and forego many of the usual set-up adjustments.

“It was the world’s simplest GP car,” he says. But, like all the best tools, no more complicated than needed to do the job:

 

Gas-fired tyre-warming oven

“Refuelling meant that you could run the car underweight for some of the race, which is why we usually used to run more than half the race distance before the pitstop – right up until the last race at Kyalami, anyway, where I switched just to confuse Renault. But I knew we had to find a way to get the tyres up to temperature before we put them on the car, otherwise it would take a lap or more after the stop to warm them and we’d fall back into the clutches of the following traffic. Michelin said there was no reason we shouldn’t warm the tyres beforehand, so we developed a gasfired tyre-warming oven that looked like a telephone box on wheels. We had to get the heated air circulating around the tyres and exhausting out of the top in a certain way so that they heated evenly. You also had to warm them quite slowly If you went over temperature just once the compound went off. There were a couple of holes in the side so that the mechanics could prod the tyres and check them. Other teams took the piss out of us when we wheeled all this stuff out — particularly when the engine broke and we didn’t get to use it.”

 

Fuel tank – with anti-explosion technique

Fuel Brabham 1983 British GP

Brabham had a novel approach to refuelling – but it wasn’t without its risks

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“I reckoned that it wasn’t worth stopping at the two street circuits, so the tank was designed to be just big enough to complete them. Elsewhere we had to get up to 35 gallons in very quickly. We thought it was easy: fill the refuelling container partly with fuel, partly with compressed air, and vent the tank. But even with a 3in hose and 1.5 bar pressure it still took too long, so we went up and up on hose size and eventually used two pressure vessels, one three-quarters full of fuel and the other just of compressed air, so that we maintained a more constant pressure.

From the archive

Eventually we were running 4 or 5 bar in the barrel and could get in 33 gallons in three seconds. But it was bloody dangerous. We had to work out how to stop the fuel guy putting the hose on before the guy on the other side had fitted the breather, otherwise you could blow it to smithereens. We tried all sorts of mechanical interlocks, none of which was really safe, so we decided that, because their faces ended up a few inches apart, we’d just use eye contact. I told the guy on the breather not to look up until he was coupled. As soon as the other guy saw the whites of his eyes, he coupled the fuel.”

 

A simple F1 approach

“To make the car simple to rebuild, I designed a front module mounted on studs to the tub. It was a one-piece magnesium casting that took all the point loads apart from the rear lower leg – the brake-reaction arm – which went back to the dashboard area. You could build the front suspension, set it up off the car and replace it as a unit. There was no steering-rack housing: that was machined into the casting to save weight, something I copied on the McLaren F1 road car. The spring/damper units were held in place by a pin at the bottom, so you just had to flick back the rocker, remove the pin and pull the unit out. You could change front springs in about three minutes, and the rears were quick to change too.”

 

Removable rear-end

Engine Brabham 1983 British GP

Brabham engine and rear end came as a removable module

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“I Invented the race rear end with the 52, which a year later everybody copied. To make the car simple to work on, the engine, transmission and rear suspension were built up as a module off the car. I decided that we’d make it so self-contained that all the liquids were in there as well, something we backed away from in later years. This meant we could set up the rear suspension off the car in the workshop, and actually run the engine to go through the gears and check the clutch. So we had completely-tested race rear ends intercoolers, radiators, everything waiting to be mounted to the back of the tub. This meant our guys were finishing at six o’clock in the evening at the races, which really pissed off everybody else who was still hard at work! The 52 was basically a front-end module, a rear-end module and the tub in the middle.”

 

Coming up for air

“The engine used a cast-iron truck turbo and there was massive heat soak into its bearings when the car was stationary. We found that if we stopped for more than about 10sec the bearing would seize. As we had air jacks I took a bleed off the air line to a device called an air ejector which blew on to the bearing housing. As soon as you plugged in the air line for the jacks you got massive airflow over the bearing housing: problem solved.”

 

Carbon copy

“We had a two-year jump on John Barnard using carbon composite and grew the amount of it we used every year. In the 52 the tub was about 60 per cent carbon, 40 aluminium.

From the archive

It had a one-piece moulding for the complete fuel tank and the whole inside of the car down to the footwell, with another carbon panel over the top. The sides and bottom were aluminium. I didn’t use carbon throughout because I was concerned about its crash behaviour.

We had a minor accident at Monaco with the 49 and the carbon just shattered, after which I talked Bernie into doing a controlled crash test. We then started introducing kevlar and using a different resin matrix, which toughened it up a bit. As we learnt more l used more, but I was cautious. Still, the 52 was the first car with carbon roll-over structures front and rear. We had to do quite a bit of work to get them to pass the FIA test.”

 

Design programme aided by exotic substances…

Nelson Piquet 2 Brabham 1983 British GP

Murray with Piquet during the ’83 season

Grand Prix Photo

“The BT52 was designed in a haze of drugs.” recalls Murray. “We had about three months to do it so I got some pills from the doctor to keep me awake. Right up to October ’82 Bernie (Ecclestone) had been telling me skirts would be legal. As we were going to take such a radical step, using pitstops, I’d thought we’d get the 1983 cars finished three months early: we already had two BT51s completed. Then all hell broke loose: we had to design a completely new car. The BT52 was so radically different that, apart from the powertrain, I think the only major items we retained were the pedal cluster and the wheels. Everything else was new. Luckily we’d already completed all the hard work on the air jacks, special wheel nuts, tyre heaters and other stuff for the pitstops on the 51.”

X-ray spec: under the skin of racing greatest machines

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