BMW M1 Rallye (Group 4 / B)

Published on: Jan 18, 2016 @ 16:35
Originally Published in: 2014 (old website)
(C) Jay Auger - website owner & author
Notice: Any form of duplication methods (including but not limited to copy/paste of text and screen capture) of the website's content is strictly forbidden.

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INTRODUCTION

The M1 was produced from 1978 to 1981 as a showcase of technology for BMW. Besides its troublesome production run, the M1 was manufactured in sufficient numbers for Group 4 homologation since it was BMW’s ambition to enter the car in the very popular Group 5 endurance circuit to go head to head with Porsche and subsequently gain much publicity on the international racing scene. In no way shape or form did the engineers even considered the M1 as a possible rally car, with the exception of a few key Frenchmen and European privateers.


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HISTORY

By the end of the 1970s, rallying had become a very popular sport, including in France, where most of the country’s rally championships were run on tarmac. Reseau BMW France thus saw an opportunity for a much needed publicity boost and race the German company’s flagship model, the M1, across the french countryside. The contract was given to Hughes de Chaunac’s Oreca Team to prepare and run the car. This was the most prominent BMW M1 effort in rallying amongst a few other privateer teams across Europe.

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BMW M1 Procar

The “M1 Rallye” used many parts developed for the defunct M1 Procar Series and carried over very similar specifications. The already wide and low-slung M1 was made almost four inches larger than factory via use of fibreglass fender flares and a large rear spoiler was implemented to aid in providing much needed high speed traction. In some other instances, ex-Procar race cars were used and modified to rally / street legal specifications.

The 277 BHP M88-code normally aspirated straight-six engine was modified to produce up to 430 BHP, which was much more than any other rally car offering at the time of its introduction to the sport. The power was transferred to the rear wheels via a shorter gearing 5-speed manual gearbox and limited-slip differential. Other improvements included reinforced hubs with a central knock-off system for quicker wheel changes and larger brakes with aluminium calipers.

BMW M1 engine (ex-Procar / rally)

BMW France‘s first outing with the M1 came in late 1981 at the Rallye du Var, driven by the very experienced French rally hero, Bernard Darniche (with Mahé Alain); 5 times French rally champion, 2 times European rally champion. In his proficient career, Darniche had won almost every French event since 1975 in a Lancia Stratos HF. Sadly, the M1 would retire with suspension failure, a bad omen of things to come…

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Darniche at the 1981 Rallye du Var

The Oreca Team would return in 1982 with a new major sponsor, Motul, and begun the season at the famous Tour de Corse event. This was to be the first of only two appearances of the M1 in the World Rally Championship (WRC) when both rally series calendars overlapped in the same event. To say that the wide BMW M1 is a car hard to handle would be an understatement, especially in the rally known for its “10,000 corners”, most of them very tight, all in a car with a tiny, almost useless handbrake. Darniche would make a valiant effort but was forced to retire when his M1’s oil pipe failed.

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Darniche at the 1982 Tour de Corse

For Darniche, the rest of the year would be unfortunately plagued with similar retirements, the only finish being a 9th place in Germany’s ADAC Rallye Vorderpfalz. It must be noted that Fritzinger Klaus also drove a similarly prepared BMW M1 in the German event and managed an incredible 2nd place podium finish.

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Klaus at the 1982 Rallye Vorderpfalz

Before his stint with the BMW M1, Darniche’s career had been very successful, thus he quit the team for greener pastures at the end of 1982. He was replaced by another experienced French rally hero, Bernard Béguin (with Lenne Jean-Jacques); 3 times French rally champion and one time European rally champion. Before jumping into the M1 Rallye, Béguin was very prolific on the international scene while driving a Porsche 911 SC.

For 1983, all Group 4 cars could get automatic Group B certification if the manufacturer applied for the change, so did the BMW M1. However, the rally car in itself remained unchanged. At this point, the Group B “evolution” (ET) feature was used to homologate the Procar special racing parts per the new regulations. However, subsequent evolutions were not made available to the M1 since it would have required BMW Motorsport to commit producing a new batch of twenty racing cars for homologation. BMW obviously had other concerns than catering to a very small rally operation and concentrated their investments elsewhere.

Bernard Béguin and the Oreca Team would give the M1 its second appearance in the WRC at the 1983 Tour de Corse but would retire with engine failure. The M1 Rallye proved time again its unreliability by not finishing a single event in the entire season. One good note is that, even though the M1 was unsuitably large and clunky for the tight French rallies, Béguin managed to not crash the car once. If only it would have stopped breaking down the M1 might have scored a podium or two in his capable hands.

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Béguin at the 1983 Tour de Corse

Despite the disastrous season, the entire team would return for 1984 in hopes for better results. A more efficient hydraulic handbrake system was homologated via the Variant Option (VO) to aid with tight corners. However, this was to be no help since the M1 Rallye yet again proved to be highly unreliable and scored a string of retirements (10 in total since 1983). At the very last rally of the season, Béguin managed to brilliantly drive the M1 to a 2nd place podium finish at the Rallye d’Antibes, only 33 seconds behind the Lancia Rallye 037 of Carlo Capone.

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Béguin at the 1984 Rallye d’Antibes

Besides this last “hurrah”, it was evident that the BMW M1 was not suited for rallying even if only on tarmac; it was too large, too heavy, too clunky, too unreliable, and overall too expensive to run. For the next season, the lesser national rallies started to become flooded with the new breed of Group B supercars, to which the M1 stood no chance against. As such, the Oreca Team threw the towel and retired the M1 Rallye for good at the end of 1984. Béguin would return to his successes with Porsche and subsequently would help bring honour back to the BMW name in rallying with exceptional performances in the Group A M3 model from 1987 through 1989.

Other privateers, such as Giovanni Rossi, would occasionally rally the BMW M1 up until the expiration of its homologation at the end of 1986. At one point in time, the M1 was proudly dubbed as “the most powerful rally car in the world” and has given rally fans something to dream about.


RALLY CAR SPECIFICATIONS

Group/Class 4 – B/12 Homologations:

  • # 670 (Group 4)
  • B-240 (Group B)
  • click # to see papers
Years active 1981~84 Homologation start:

  • December 1st 1980 (Group 4)
  • March 1st 1983 (Group B)

Homologation end:

  • December 31st 1986 (Group B)
Engine
Type M88 code, I-6, DOHC 24v, gas located middle longitudinal
Displacement 3453 cc WRC = 3453 cc
Compression ratio N/A
Output power – torque 430 HP @ 9000 rpm 288 lb-ft (390 Nm) @ 7000 rpm
Materials block: cast iron cylinder head: aluminium
Aspiration
  • Normal / Natural
  • Bosch Kugelfischer mechanical fuel injection
  • individual throttle valves / inlet pipes
  • magnesium intake manifold
Ignition N/A
Cooling system water-cooled
Lubrication system dry sump 2 oil pumps
Transmission
Type rear wheel drive 5 speed manual gearbox
Gearbox ratios
  • 1st: 2.420
  • 2nd: 1.610
  • 3rd: 1.140
  • 4th: 0.846
  • 5th: 0.704
  • R: 2.86
  • 1st: 2.230
  • 2nd: 1.610
  • 3rd: 1.310
  • 4th: 1.090
  • 5th: 0.917
  • R: 2.86
Differential ratios
  • 4.22
  • 4.00
  • 4.63
limited slip rear differential
Clutch twin plate – hydraulic
Chassis-body
Type E26 chassis, square-section steel-tube spaceframe with roll cage, 2 door coupe fiberglass bodyshell
Front suspension double wishbones, coil springs, shock absorbers, anti-roll bar
Rear suspension double wishbones, coil springs, shock absorbers, anti-roll bar
Steering system
  • rack and pinion
  • pneumatic assist
14.9:1
Brakes
  • F: 4 piston aluminium calipers & 332/300 mm ventilated discs
  • R: 2/4 piston aluminium calipers & 332/300 mm ventilated discs
  • hydraulic parking brake (revised 1984)
dual circuit with servo, adjustable ratio split front to rear
Dimensions
length: 4536 mm (178.6 in) width: 1920 mm (75.6 in) height: 1110 mm (43.7 in)
wheelbase: 2600 mm (102.4 in) front track: N/A rear track: N/A
Rims – tires
  • N/A
  • N/A
Dry/Unladen Weight 1150 kg (2535 lb)
Weight/power 2.7 kg/HP (5.9 lb/HP)
Fuel tank 116 litres

HOMOLOGATION VERSION

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More often than not, ‘homologation specials’ have gone into history as the finest road cars of their era. A great example is the BMW M1, introduced at the 1978 Paris Motorshow as the German company’s latest GT racing weapon. Problem was that before the M1 could race in the intended Group 5 class, 400 road cars had to be built and sold. It would go a little far to describe these as street legal racing cars, but they offered supercar equalling performance. Today, it is considered one of the most legendary BMWs ever built, but its conception, construction and racing career were far from trouble free.

The M1 was very much the brainchild of BMW Motorsport’s founder Jochen Neerpasch. In 1976 he decided to start with a clean sheet for the replacement of the highly successful, but ageing 3.0 CSL racing car. He had set its sights on the world manufacturer championship, which was held for the Group 5 class. The rules dictated a 400-car production minimum, but other than that were pretty liberal as to what modifications could be carried through. Taking full advantage of the clean sheet, Neerpasch laid out a mid-engined two-seater, to be powered by a 3-litre V10 engine. He expected the car to be highly competitive on the track and in addition help BMW to enter the elite group of supercar manufacturers.

One of the first problems that Neerpasch had to tackle was BMW’s inexperience with designing and building a mid-engined supercar. So he called in the help of the much more experienced Italians. Giorgietto Giugiaro’s Italdesign was commissioned to design the exterior, while Lamborghini was given the responsibility to construct the car. Giugiaro masterfully combined elements from the Paul Bracq penned BMW Turbo Concept of 1972 with his familiar wedge shape design. The end result was a feast for the eyes and even today looks remarkably modern, especially compared to other supercars of the day, like Lamborghini’s Countach.

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The Italdesign labeled fibreglass body covered a state-of-the-art spaceframe chassis, constructed from square section tubes. The fully independent suspension and vented discs all followed the latest design trends. Unfortunately the V10 idea was binned as being too complicated and above all to expensive to design and develop in time. Instead the M1 was equipped with the familiar straight six out of the 3.0 CSL racing cars. Displacing just under 3.5 litres, it produced a hefty 277 BHP in road tune. Mated to a five speed gearbox, the 24-valve engine was mounted midships between the passenger compartment and the rear axle.

The reception of the M1 in Paris was overwhelming and the gathered media could not wait to get their hands on BMW’s first supercar. Wait is exactly what they had to do and at one point it looked like their patience would be tested indefinitely. After constructing just four cars, Lamborghini’s future was threatened by a looming bankruptcy and the M1 had little priority. Fortunately all was not lost as Giugiaro jumped in and offered BMW to build the M1 instead. BMW agreed and the construction finally got underway. Before being delivered to a customer, the M1 had travelled from Giugiaro’s small factory in Turin, to Baur in Stuttgart where the mechanicals were mated to the body and finally to Munich, where the often many quality issues were ironed out.

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Even though production was now under way, the delays had scared off possible customers, which meant that the homologation requirement of 400 sold cars was hard to meet. Neerpasch nevertheless had the Motorsport department prepare a number of racing cars for the 1979 season. He had thought up of an excellent series to race the cars until they were fully homologated; Procar. This one make championship supported the Formula 1 rounds. In addition to the privateer entrants, BMW prepared six cars for the top-six qualifiers of the Grand Prix. With the exception of those contracted by Ferrari and Renault, the drivers were more than happy to participate.

The Procar series thus offered the crowds the opportunity to see their favourite drivers active in more than one race over the weekend. The races were often very spectacular and involved quite a bit more close action than most Grands Prix. Niki Lauda was crowned champion in 1979 and he was followed by Nelson Piquet in 1980. For various reasons, many of them political, the M1 Procar championship was not run again. By this time the competition cars were fully homologated and scored some great results. Unfortunately they faced the virtual unbeatable Porsche 935 K3s. The biggest success came in 1981 when David Cowart Kenper Miller drove their Red Lobster sponsored M1 to the IMSA GTO Championship.

Eventually Giugiaro/Baur/BMW produced 457 M1s, including all the racing cars. Financially the M1 was certainly not a success and the racing record, especially for a BMW, is not overly convincing either. If Neerpasch had not come up with the Procar championship, the M1 would have been a complete disaster. Well maybe not, actually most certainly not; the M1 is a superb machine both to look and also to drive. For us enthusiasts that is all that matters and after trying to forget about the M1 for several years, BMW have come around to appreciate the M1 for what it is. That is best illustrated by the big celebrations of the car’s 30th anniversary, highlighted by the M1 Hommage Concept and a Procar Revival race held before the German Grand Prix, which was appropriately won by Niki Lauda.


ROAD CAR SPECIFICATIONS

Class Grand Touring Homologations:

  • # 670 (Group 4)
  • B-240 (Group B)
  • click # to see papers
Production 1978~1981 (457 units)

  • 57 racing units
  • 400 road units
Assembly: Germany
Engine
Type M88 code, I-6, DOHC 24v, gas located middle longitudinal
Displacement 3453 cc
Compression ratio 9.0:1
Output power – torque 277 HP @ 6500 rpm 243 lb-ft (330 Nm) @ 5000 rpm
Materials block: cast iron cylinder head: aluminium
Aspiration
  • Normal / Natural
  • Kugelfischer mechanical fuel injection
  • individual throttle valves
Ignition N/A
Cooling system water-cooled
Lubrication system dry sump 2 oil pumps
Transmission
Type rear wheel drive 5 speed manual gearbox
Gearbox ratios
  • 1st: 2.420
  • 2nd: 1.610
  • 3rd: 1.140
  • 4th: 0.846
  • 5th: 0.704
  • R: 2.86
N/A
Differential ratios 4.22 limited slip rear differential
Clutch twin plate / hydraulic
Chassis-body
Type E26 chassis, square-section steel-tube spaceframe, 2 door coupe fiberglass bodyshell
Front suspension double wishbones, coil springs, shock absorbers, anti-roll bar
Rear suspension double wishbones, coil springs, shock absorbers, anti-roll bar
Steering system
  • rack and pinion
  • pneumatic assist
14.9:1
Brakes
  • F: 4 piston calipers / 300 mm ventilated discs
  • R: 2 piston calipers / 297 mm ventilated discs
dual circuit
Dimensions
length: 4343 mm (171.0 in) width: 1829 mm (72.0 in) height: 1142 mm (45.0 in)
wheelbase: 2560 mm (100.8 in) front track: 1550 mm (61.0 in) rear track: 1576 mm (62.0 in)
Rims – tires
  • N/A
  • N/A
Curb Weight 1297 kg (2860 lb)
Weight/power 4.7 kg/HP (10.3 lb/HP)
Fuel tank 116 litres

VIDEOS


REFERENCES

 Affiliates Program – (free delivery worldwide!)

 BMW M1: The Story (German)

Group 4 Group 4 – From Stratos to quattro (English)

  • Any purchase you make through the Affiliates program helps support the Shrine!

(C) Article by Jay Auger – website owner & author

  • Images & videos are the property of their original owners
  • All homologation papers are the property of the Fédération Internationale de l’Automobile (FIA): SOURCE
  • Eifel Rallye Festival Pictures used under permission – McKlein Publishing
  • DISCLAIMER / LEGAL NOTICES

SPECIAL THANKS:

  • Leo Rossi (specs update & video)

WELCOME TO THE ENCYCLOPEDIA OF THE GOLDEN ERA OF RALLYING