Last Of Its Kind: The Only Surviving Sauber Group 5 BMW M1

Photos by Wolfgang Maringer, c/o Adrian Gattiker

The BMW M1 didn’t see the motorsport life that was once in store for it, but it did spawn a few notable competitors, one of which is unquestionably the Group 5 M1 project by Sauber. I had the chance to get into the history of what’s known to be the only surviving example.

With the chassis and suspension designed by Dallara of Lamborghini and Formula 1 fame, a body by Giorgetto Giugiaro, who went on to be awarded the accolade of Car Designer of the Century, the M1 originally built by Lamborghini was the first car designed for competition from the ground up by the recently formed BMW Motorsport.

The basics of the story aren’t as special as the ingredients: Lamborghini was struggling with bankruptcy so the build deadline for the 400 units needed for homologation was far from achievable and a new production process had to be pieced together; and the Procar series, spectacular as it was to have the day’s current F1 drivers hammer it out before a Grand Prix, was put together because the cars weren’t eligible to race in any other series not built around them.

For 1981, two years behind schedule, several teams did take the finally homologated Group 4 cars and converted them to race in the Group 5 class, but Sauber, expanding on the their sports car racing collaboration with BMW, built the only two Group 5 cars from scratch. Hear the name Sauber today and perennial F1 midfield contenders, or the silver Group C Mercedes-Benz collaborations called the C9s at the 1989 edition of Le Mans might spring to mind, but their history goes all the way back to the late 1960s and includes both gorgeous, and perhaps not so gorgeous, race car creations. The M1 is most definitely in the former category.

The Swiss team had run their own cars at Le Mans and the Interseries, which was the European equivalent of the American Can-Am series, but these high downforce cars bore no resemblance to anything on the road.

With the M1 Sauber saw an opportunity to run with a recognizable shell with the added benefit of production cars sales attached to the project. It was a good plan, and two cars were made with lightweight, fully adjustable tube-frame chassis and aerodynamics that could be set up for each circuit. One was run by GS Racing with the high-profile driver pairing of Hans-Joachim Stuck and Nelson Piquet in the psychedelic red and white lines of the BASF livery, while the white with blue and green “splotches” Würth-sponsored car was run by Sauber themselves, with Marc Surer and Dieter Quester taking care of driving duties.

The cars were a significant 150kg lighter than any of the other M1s converted from their Procar spec, and could lap the Nürburgring Nordschleife a full 20 seconds faster. For all intents and purposes they were in a class of their own. They were also the last cars that Peter Sauber physically worked on before taking up a more supervisory role.

The debut race for these cars was the Silverstone 1000km. It didn’t go to plan though, and the GS Racing BASF car, the only one entered, retired halfway through with gear selection issues. By the following event however, all development pains were soon forgotten when Stuck and Piquet took a magnificent win at the grueling Nürburgring 1000km ahead of some serious competition, not least the works-run Porsche 910/80. The project looked to have come good after all… Unfortunately though. the win in the Eifel mountains would prove to be a false dawn.

At Le Mans the BMWs were outclassed by the well-developed Porsches and the Lancia Beta Montecarlos, and recorded a double retirement; an accident for the GS car and engine failure its Sauber sister. Then things got a lot worse; at the next race Stuck had a huge, fiery accident. He was lucky to be able to walk away, but the car was left a smoldering write-off. Only the two chassis were ever made, so the Wurth car is the only example of its kind to exist today.

The rest of the year failed to bring any significant results for the remaining car, and the project was brought to an anti-climatic end when the rules were changed in favor of Group C, which the manufacturers were much keener on at the time. So at the end of the season the surviving Sauber M1 was sold on to a Danish driver who entered it in events in Scandinavia until the mid ‘80s, before Sauber bought it back and kept it as part of his private collection.

The car was then seen very rarely, only when Peter decided it would be nice to blow the dust off, but in 2013, after 25 years of owning it, he decided the time had come to let it go. However when money is not your motivation for a sale you are afforded the luxury of being able to choose who becomes the next owner, so instead of advertising it he looked for the right person to pass it along to.

Adrian Gattiker had been racing Porsches for many years, but like many competitive drivers who get to a certain age keeping up with the unceasing tide of technology and its inherent cost started to lose its appeal, and so he started to look for a classic car to enjoy—something a bit special perhaps. A mutual friend of Sauber and Adrian who found out about the M1 sale put them in touch, and while it would be normal for a potential buyer to discuss the price Adrian was interviewed about his intentions for the car and his ability and willingness to give it a thorough restoration instead. Fortunately he was found to be acceptable, and a large but undisclosed amount of money was handed over on the understanding that the car would be very well looked after.

Adrian duly had it stripped down to its constituent tubes and nuts and bolts. Of course the car wasn’t in bad condition, as it had been cared for in the collection prior, and hadn’t been driven in anger since 1987 so it wasn’t a restoration in the sense of of replacing rusty metal and worn out parts. But every single part was examined to see if it could be refitted or needed to be replaced anyway. It was a laborious process and cost more than some other exotic classic cars would be to buy, but if ever there was a one of a kind car worthy of a no costs consideration rebuild, then this is a good candidate.

The gearbox was made by Hewland, but none of the internals were specific to just this car, so new bearings and seals were old but stock items. Similarly for the M88/1 engine, parts like gaskets, roller bearings, pistons, valves, and springs weren’t hard to source.

Something that is definitely unique to the Group 5 M1 though is the electrical system, but Peter Sauber helped out by putting Adrian in touch with the same guy who worked on it 35 years ago. When he came to the workshop and saw the car again after so many years he was amazed to see his handiwork was still holding up.

After more than two years in the workshop the end result was a car that was as good, if not better, that it was when it was first wheeled out of the Sauber workshop in 1981. And so came the time to fire it up.

The first drive to run everything in was at Mugello, and it passed all of the systems checks without issue. But for a more serious test Adrian went to the Red Bull Ring in Austria to see what it was capable of with more of a purposeful run-in. The difference between the production cars modified to race that Adrian was used to and this purpose-built, no-compromise BMW was instantly apparent, as was the complete lack of driver aids, which were still well into the future when the M1 was designed.

The hardest thing to get used to was the downward gear shifts. The ‘box is not synchronized, so under braking Adrian has to touch the gas pedal to match the engine revs before he can shift down. It’s something that drivers of the ‘70s and ‘80s were well used to, but it took Adrian quite a few laps before he could do it with confidence. If you mess it up you could well be looking at the corner from the wrong window and end up in the gravel.

Something that will probably take a lot longer to get used to is the sound of that glorious straight-six right behind the bulkhead. Power is reduced from what it was capable of producing in its racing days (above 500), so the engine and transmission are not put under unnecessary amounts of stress, but it is still tuned enough for big bursts of flames to spout out all the back on over-run.

It’s also a light car in addition to being a fast one, about 400kg less than anything Adrian has raced before, so it’s easy to get slowed down and turned in (as long as you got the gear change right), but that lightness also makes the car twitchy and unstable in some corners. Over the course of the weekend the lap times came down considerably, but Adrian hasn’t pushed the car anywhere close to where he assumes its limit of adhesion is yet, as it’s far too precious of a car to put it at risk just for the sake of it.

And not having complete trust in the other people sharing the circuit with him is the reason he is also not too keen to race it in historical events… which with a car as unique as this is perfectly understandable.