BMW’s Group A M3 saloon racer is designed to bring Grand Prix standards to the new world saloon championship. Jerry Sloniger drove it at a wet and slippery Hockenheimring – Motor
“It’s about as close as we could get to our proper F1 engine. Lots of the same parts.” That casual assessment came from the very BMW Motorsport man responsible for the powerplant lurking inside this plain wrapper called a Group A saloon racer, Guaranteed to grab your attention, right? It certainly got all of mine. Especially since it came just as I was about to eel my way into Recaro’s lastest seta for a few laps around Hockenheimring with the great white hope of Bavarian motor racing.
“What was that power figure again?” I asked, attempting the tone reserved for mum’s next shopping car. “About 300bhp today, up around 8000rpm. But it’s very elastic.” “It” also weighs hardly more than the 960kg (2117lb) class minimum and even I could see that steady rain was neither limited to the padlock nor likely to cease before noon. (Local noise rules forbid full-race, open exhausts after midday).
“Great,” Motor’s safe, dry editor told me. “300bhp in the rain is just the angle we want.” I do feel “angel” was an ill-chosen description of my drive. Actually 300bhp is barely a third of the power BMW’s real F1engine puts out. On the other hand, it is half-again the rated power of a road-going BMW M3 which is reckoned to be pretty brisk, even among hot sporting saloons. An M3 was the homologation base for this works racer.
For most of the 1980s BMW’s chosen arena was Grand Prix racing, but now that is winding down they plan a comeback with the sports saloons. Yet again. This is a realm which the Munich firm have dominated before, and which they clearly intended as at least second string to their bow as far back as 1983, when the M3 project began.
Thomas Ammerschläger who masterminded the race Capris before doing general touring car work at Audi, only joined BMW Motorsport as Manager of Vehicle Development and Production in early 1985. He insists now that no more than ten per cent of the current racer car is his. The rest was already settled – although BMW’s M-branch did get to designate shapes and components they needed homologated in M3 so they could later be used in race cars. It seems, however, that road car and thus racer would have been even hotter – perhaps turbocharged – if BMW management had realised they would be racing saloons, not GP cars, in 1987.
In recent years such tintops have often raced before crowds so small you might think it was forbidden to watch. Young drivers preferred almost any ride to a work saloon contract. Now FISA are promoting a world championship, alongside the existing European one, plus various national title chases. BMW won’t actually send a “works” team to any of those – but they will back specific teams in all of them.
Each such team – Zakspeed who will run the revived “BMW Junior Team” of corners in the German title series. Linder for Europe and Schnitzer to take on the world – will get “kits” which become race cars when proper mechanical expertise and a thick instruction book in German and English are applied. Anybody can buy such a kit and some 30-40 already have, including four to Australia inviting a vision of a youthful racer sitting under his Christmas tree, surrounded by car parts and trying to fathom how to “tuck suspension leg A into slot B.”
What a mere DM 150,000 (£53,000, not quite triple the M3 price in Germany) brings, in fact, is a complete race engine, a raw body-cum-roll-cage and all the good bits like suspension, brakes, tank and connections. BMW would clearly prefer teams to leave their engines as-delivered, and nourish the probably-forlorn hope that each team will tell their assigned BMW engineer any secrets they discover. To be passed on the rest? Hardly likely. At the same time, BMW themselves will continually update the parts for everybody.
If the homologation car (5000 built in the previous year) doesn’t enjoy a turbo, neither can the Group A machine. The same rules explain why the road M3 has two cams and four valves per cylinder. On the other hand, both private drivers and their mechanics will find non-turbo power easier to deal with.
For Group A, an engine must also remain within its nominal displacement class: in this case they increased bore from 93.4 to 94mm (stroke remains 84) to fill the entire 2.3 litres. The class limit is really 2.5, but that would require “evolution” homologation, meaning another 500 similar cars. As Ammerschläger puts it, this engine is nowhere near the limits to its development. It does have 12:1 compression, plus the cam timing of BMW’s F2/F1 machinery and permitted monoposto-engine parts like valve springs.
Nor do we have to take the quoted output of 300bhp too seriously. Wolfgang Hatz, their young engine expert, only grins. BMW never reveal power curves until an engine is retired. He does admit that the Bosch Motronic management system has been considerably modified for this car, it works without an air flap, and output can be tailored to each track by changing the microchip. Just like F1 cars. In fact, BMW have a “Group A” programmer ready in the pits. Plus a set of flashing light dots in red, yellow and green to tell a diver how he stands on fuel consumption at any given moment.
They claim you can run this car down to the last one per cent of a special, 24.2 gal foam-filled tank. Thanks to consumption of 8.1mpg at speed, BMW even hope to skip one stop per race at some tracks.
The gearbox is a Getrag race unit, right out of BMW’s 6-Series race coupés, like so many M3 parts. Brakes are probably the most-altered item: Brembo ventilated and cross-bored discs in front, ATE at the back. BMW don’t reckon ABS is worth having on the track, unlike Porsche. Suspension changes are strictly limited, but Uniball joints can be used; hubs and larger wheel bearings come from the competition 635 and Ammerschläger is particularly proud of a special rear leg with threaded sleeve with allows quick castor and camber adjustments. So far, only Pirelli make suitable tyres in a sufficiently wide range.
BMW deny that they would consider four-wheel drive for racing – BMW are not a rally firm. No 4wd, unless FISA drastically reduce permitted tyre widths.
The interior goes from four seats to one and that is a Kevlar bucket weighing barely 4kg (8.8lb). In fact, they are close to the 960kg (2117lb) limit, and admit that getting down to 940kg for the 1988 season will be tough. But a clever roll cage – steel, because it is stiffer yet even lighter than aluminum – not only encloses the driver from engine bay to rear suspension turrets, but also makes the car three times as stiff as a road model. Almost formula-car standards.
Safety isn’t something you have to test personally, so I merely made sure that the rear-mounted tank was partly protected by the cage – and discovered a clever BMW trick. It seems the greatest danger to saloon racers after a really heavy thump is a running engine and potential fire. BMW adapted airbag sensors to go off when 5g deceleration occurs, turning off the fuel pumps.
Another prime concern was quick and easy service during an event. Your M3 racer kit comes with air-pressure jacks at all four corners and high-speed fuel fillers located in the tail panel. The thinking here is that refuelling men don’t need to hoist a full can above their waist level and besides, refuelling is kept out of the way of tyre changes.
Neither time nor the elements encouraged the taking of our own performance figures, so I’ll quote BMW’s. For a start, axle ratios are not limited in Group A, so BMW offer a range from 3.15 to 5.28, to go with a direct fifth gear and rather tall (2.337) bottom cog. This permitted them to give a 0-60mph time of some 4.5sec with the 4.44 axle (versus 6.7 for a standard M3 and its 3.25 ratio). Top speed is quoted at 175 using the latter ratio, which would be good for 145mph in a road M3.
Given the rain and the fact that Motorsport themselves only have two of these cars – with one on detached duty for motor shows – it didn’t seem advisable to test the very outer limits. Still, race cars have become much easier to learn about since the days of the vertical torque curve and 1mm clutch pedal travel. Hatz was telling the truth about the elastic power; there is entirely viable power from 5500 to the cutoff, which was set at about 8300 for our runs. And there’s real poke about 7000. BMW may still be experimenting with various clutches but the Fichtel & Sachs we tried was progressive, light and rapid.
The Getrag box has suitably close spacing and a very smooth, precise gate, requiring virtually no driver effort for quick shifts. The one component which did take some working-in was those enormous brakes. Just getting them up to temperature on a cold, damp day was a chore. Steering, despite nine-inch-wide wheels, proved lighter than expected. A slippery surface helped.
With full tank this M3 is balanced 50/50, but we weren’t carrying the full 24.2 gallons. Even so, handling on the day was neutral until you began to push, with easy tail control on the throttle. The car has ample adjustment for any sort of track where saloons usually race. It gives the kit builders something to devastate the competition.
BMW believe their likeliest rivals will be Ford and Holden, with everybody from Maserati to Nissan mixing in too. In fact, they should and do hope that every company building family saloons will try to race them as well, to attract maximum public identification. Second, they desperately need well-promoted events spectators might want to see.
Munich really face two problems as they ease out of F1. Not just, can they win? But also, will anybody notice when they do? Unfortunately, the cleverest race team in the world can’t do much about the latter factor, but BMW at least have a purpose-conceived car descended directly from a cleverly-homologated base model. It might not be exactly what they would have planned back in 1982 if somebody in management had realised BMW GP efforts wouldn’t survive the 1980s, but this Group A M3 is anything but provisional. It’s a full track machine with the word “compromise” banned.
In fact, it’s as close as BMW can get to F1 technology while still being able to pass Group A technical inspection.
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8. April 2009 at 3:49 am
Hi from which magazine (number & year) is this article ? Thanks !
8. April 2009 at 8:35 am
It’s from Motor Magazine. March 1987