Under Scrutiny - Brun Technic

The Underdog

Walter Brun, 1986 World Team Champion in sports car racing, will forsake Porsche in the year ahead and start the season as he means to go on, in a new car bearing his own name. The Brun, to be powered by a 3½ litre Judd EV V8 engine, is on course for testing and development well before the season opens in Suzuka. It is being constructed in Brun Motorsport’s workshop in Stans, Switzerland, from parts designed and manufactured in England.

The plan is to run two cars in the World Sportscar Championship, and perhaps at Le Mans. Although Brun disclosed some months ago that he planned to keep his Porsches for the 24-hour race, the decision has not yet been made whether to run them. Brun, Jesus Pareja and Oscar Larrauri have a score to settle at Le Mans, and will drive the car that gives them the best chance of success.

Until now little has been revealed about Brun Technics, the small unit near Basingstoke. Even in December, with the sports car “75 per cent finished” there was little to see at the smart, modern factory unit, parts going almost direct to Glans for assembly. “Aren’t you tempted to fit the parts together, to make sure they match?” Chris Humberstone, who directs Brun Technics Limited, looks surprised. “No, there’s no need. Precision is a key factor here, and everything is designed to fit perfectly. We’ve been surprised that panels don’t always go straight onto a Porsche 962, for instance, and we mean to see that everything on our cars is interchangeable.”

A great deal has been achieved in the two years of Brun Technics’ existence. It was established in February 1989 to support Brun’s involvement in Formula 1 (“I can have wishbones made in England in two weeks, where in Italy it takes two months,” he said at the time). George Ryton headed the company and concentrated on the design of a new Brun Formula 1 car while Steve Ridgers, ex Spice and recruited from TWR Jaguar, was engaged in July 1989 to design the new Group C car. What the two machines had in common was the Neotech V12 engine, something that has been shelved for the time being through lack of finance, but not forgotten.

Walter Brun was mighty impressed by the Neotech which powered his Porsche 962C for a test at the Osterreichring last March, and so were a lot of other people. It had reached the state where it needed a lot of money spent on development and productionising, but all efforts to raise the finance failed. SEAT, the subsidiary of Volkswagen, seemed a real possibility In the autumn but eventually rejected the idea, leaving Brun with no alternative to going with Judd. “The Judd will be a very good sports car engine,” he insists, and there’s no reason to doubt this. All the same, Brun’s ambition was, and is, to tie up with a major manufacturer, just as Peter Sauber did with Mercedes.

George Ryton left Brun a year ago, to join Tyrrell. Brun’s involvement in Formula 1 wasn’t a happy one, and when the Eurobrun failed to qualify for a single race in 1989 Brun decided to give priority to the sports car project, an area in which he felt happy and competitive.

A major factor in the decision, of course, was the failure of a major Formula 1 sponsorship deal to reach the contract stage.

Rsrton was replaced by Chris Humberstone, who has to think hard how to describe himself. “A jack of all trades, master of none,” he suggests helpfully. We settled for “a body engineer,” although he has a formidable reputation as an organiser who knows the business of motor racing inside out.

Humberstone has worked through the motor industry, including the motor trade, with companies such as H.R. Owen, and Wood & Pickett (where he was involved with the famous ‘Peter Sellers Mini’ line of development). From there Humberstone went to work on one of the world’s slowest cars, the Range Rover “Popemobile” with a top speed of 30 mph, followed by deep research into kevlar and other lightweight, bullet-proof materials.

It was a short step from there into the world of motor racing, which had been a hobby of Humberstone up to that time, as he became manager of the FORCE Formula 1 factory in Colnbrook (now occupied by March Engineering) in 1981. He was undertaking contract work for Benetton when he was approached by Brun in 1989, and has kept to an exacting schedule in producing the Group C car on time.

The Group C car was designed from the start to accept the Neotech V12, an unstressed engine which needs supporting. The rear venturi under-tray is securely mounted at the rear of the bulkhead and contributes to the car’s stiffness, which should be “exceptional” according to Steve Ridgers. Stiff but not heavy the Sports car is expected to be well under 750 kg when it’s weighed for the first time.

The Judd engine is very compact, of course, in the space designed for a V12, and the Brun could easily be adapted to take 10- or 12-cylinder engines. Once the team is established, Brun would be happy to supply cars on a customer basis.

The V8 is actually shorter than the new six-speed gearbox which is designed by Ridgers and breaks new ground. For one thing it is a ‘dry sump’ gearbox, with pressure feed for the oil ways, and for another the gear cluster is ahead of the differential, a modern Formula 1 layout.

That apart, the Brun is quite conventional. The composite materials monocoques are made by Advanced Composites but the bodywork is manufactured by Brun Technics; the front suspension is inboard, transverse pushrod but the rear suspension is more like the Jaguar’s in being outboard, within the wheel rim. Wheels come from BBS, carbon brakes from Brembo, and dampers from Bilstein.

The tyres that Yokohama will supply are particularly tall, with 28-inch diameter at the rear, and that’s a bonus since the driveshafts will be above the venturi tunnels and there’s no need for slots in the material.

All the machined components are made in another workshop owned by Walter Brun at Knaphill, near Woking, allowing the company to produce specialist parts in secrecy. Altogether eight people work at Basingstoke and another four at Knaphill, a very conservative number for such an ambitious project.

Wind tunnel tests were carried out with a one-third scale model at the MIRA facility in the Midlands, and Humberstone believes that good aerodynamics will be the key to good performance. . . assuming a high level of reliability, which is the top priority. “A small change in the wind tunnel can be worth 50 horsepower,” he says confidently, pointing out that with twice the floor area of a Formula 1 car, and much larger body surfaces, a well designed car could quite easily overcome a power deficiency.

Humberstone agrees with March’s Dave Reeves that sports car racing is about to undergo a revolution as the gap to Formula 1 begins to close. “A culture shock” is how he describes the new technology soon to be seen in Group C, and he predicts that at fast circuits such as Monza the sports cars could break Formula 1 lap records (as they sometimes did in the 3-litre era of 1968-75) due to the enveloping bodywork.

“Formula 1 is an enormous technical achievement,” Humberstone believes. “Not so long ago one designer was responsible for the entire car, but now he heads a team that could put a man on the moon, if they wanted to. Now, I believe, sports car racing will be sucked along in the wake of Formula 1.”

Costs, of course, will escalate. No-one believes any more that turbocharged engines were unduly expensive. “The components now will be much lighter, ‘lifed’ for a race or two, then they’ll have to be thrown away. The 962 was built for Le Mans, and could go a whole season without much attention. I’m afraid all that will change. The new cars will be built for the sprint races, and ten of those would hardly equal the distance covered at Le Mans, so clearly that will be a problem, when it comes.”

Brun Motorsport is keeping two Porsches for Le Mans, but they will not be eligible for the 24-hours after the 1991 race, so the temptation to run the 3½-litre cars will be strong. When the new season begins Walter Brun’s chances of success will, in theory if not in fact, be as high as they were in 1986. An underdog he may be, against Mercedes, Peugeot and Jaguar, but Le Mans 90 showed that he has a powerful bite. MLC