Back to the point

A Brabham BT52 is set to run again after BMW breathes fresh life into its sharp and shapely form
Writer Alex Harmer

When BMW sold its Formula 1 team back to Peter Sauber in late 2009, it was a poor finish to a programme that had promised much.

Its hand forced by a collapsing economy, the company left the sport with only one Grand Prix win under its belt as a constructor: Montréal 2008, courtesy of Robert Kubica.

But BMW’s F1 history is long and it won’t let recent disappointments cloud past successes.

Since last October, in a corner of one of BMW Group Classic’s Munich workshops, a group of retired engineers has been working without fanfare to rebuild the company’s F1 zenith: the 1983 Brabham BT52. Bernie Ecclestone’s team worked with BMW from 1981 to 1987, peaking in ’83 with a world championship for Nelson Piquet in Gordon Murray’s striking car. It was the first world F1 title for a turbocharged engine, designed by Paul Rosche and his team of engineers.

Murray and Rosche gathered with the marque’s motor sport director Jens Marquardt, designer Adrian van Hooydonk and the crew of former engineers and mechanics who put the car back together. The latter group worked under Rosche during the company’s time with Brabham (“We’re like the Buena Vista Social Club!”) and to celebrate the car’s 30th birthday they’re aiming to run it up the hill at the Goodwood Festival of Speed, with Piquet scheduled to take the helm.

Before this particular BT52 got anywhere near asphalt, it needed serious work. Several parts were missing and required fabrication. That’s where BMW Classic came in.

“Everything here needs a project code,” says BMW’s Group Classic boss Norbert Knerr, “but the BT52 didn’t have one – it was under the radar. We didn’t have a blueprint or a plan. But it’s a big deal to get this car rebuilt for its 30th anniversary and we realised we had the capability to do everything in-house. We wanted to be able to run the car and so we created some space for the guys to work. We could also give them access to our design department, so we could scan the older parts and rebuild them using modern F1 technology.”

Working ‘under the radar’ is familiar territory for BMW engineers; Rosche’s department was always run on a tight budget, occasionally ignoring orders to stop pushing, carrying on work secretly in the evenings. The restoration was familiar territory for this bunch. Getting to grips with new equipment was part of the job during one of F1’s technological booms. During the early ’80s BMW developed the first modern telemetry system in F1 and experimented with fuels, leaving its rivals scrabbling to keep up. Such work paved the way for this project 30 years down the line.

“We scanned the car without having to touch it,” says engineer Werner Mühlbach, “taking a 3D image with 15 million digital reference points.” New parts can then be machined using that data and the original specifications. “In the old days, you’d have tech drawings on the back wall of the workshop. Now it all fits on a USB stick. The nose section and the rear bodywork are newly built.” Carbon fibre technology was still in its infancy when the BT52 was created, so the car is a mix of new and old weaves. Not that you can tell from the outside. “This is still a championship-winning car,” says Mühlbach, “just thoroughly reworked and refreshed.”

The BT52’s turbocharged 1.5-litre inline four powerplant was something altogether more familiar for Munich’s finest. The engine was painstakingly refurbished and rebuilt before being run through BMW’s rigorous tests. Like the body it is running with both old and new parts, some of which were hard to find. New end pipes had to be made for the enormous turbo and the team had to find a company willing to sell them five fuel filters, the smallest usual shipment being 2000.

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The engineers were relaxed when talking about rebuilding the turbo lump, a process to which they needed little acclimatising. They were content to reminisce about old times and the trials they faced as they developed the car. At times it could be painful.

An early telemetry device took the form of a balloon that had to be placed at the highest test area to receive transmissions, but could not be secured. If the car hit a bump or cornered too fast, the measuring equipment would have to be recalibrated. At least for this project the technology already existed.

Murray once asked Piquet how he coped with the power. “I don’t drive,” he replied, “I get the car in the middle of the circuit and press the accelerator.” The engine was capable of putting out up to 1500bhp, and Rosche remembers the ’80s as a relentless quest for bigger numbers. “We knew the car had too little power to begin with, but after a while it had too much. It was addictive. We had a great working atmosphere and, although we went home to sleep a little, most hours were spent in the workshop. To win, that was a given.”

They all agree on the effect Piquet had.

“I think Nelson was of paramount importance,” says Murray. “He was a world champion and when things didn’t look good he was always committed. Nelson was always up for testing, he just wanted to be in the car. He was also the only one who could really handle Bernie.” The many pranks he pulled – a briefcase full of spiders here, a plate of snakes for dinner there, sealing a napping Rosche in his car with a burning rag – are discussed fondly, more so than they were at the time.

Murray and BMW ended up having a long association, working together again on the McLaren F1 road car in the mid ’90s, but they’re all still proud of the BT52. “Designing this car is something that’s stayed with me all my life,” Murray says. “I even built my niece a soapbox in the same shape.”

Marquardt, quiet for most of the day, puts it simply: “I’ve never seen this car looking so good.” At the Festival of Speed everybody else will have the chance to see it too, with that distinctive red and white helmet on board.