This is the BMW M1 that you never knew existed
Image from WSupercars
The BMW M1 is undoubtedly the most iconic BMW ever produced. The clean lines from Giorgetto Giugiaro are still breathtaking and BMW M’s magnificent inline-six is silky and smooth, but with tons of grunt. The M1 itself was already enough to be remembered as a legend. However, BMW did not satisfy there. It developed the M1 Procar racing program and later participated in the Group 4 category racing. But there is a variant of the M1 that even the most die-hard BMW M fans do not know, the M1C.
Image from Vintageracecar.com
Hence the name, and the bodywork, you might be suspecting that this might be BMW M’s Group C racer. Sorry, but you are wrong there. The M1C never raced in Group C, but instead to its American counterpart, IMSA GTP. BMW was no new face in the IMSA scene; privateer CSLs and factory-backed 320is often raced in IMSA, and BMW was more than eager to perform well. When it was announced that Group C racing will start in 1982, BMW wanted to gain experience and data as early as possible and decided to use Group GTP in IMSA.
BMW March M1. Image from Engine Swap Depot
However, BMW sadly was not in a good financial situation to build a whole new car just for GTP racing. Thankfully, they had the magnificent M1, which has been proven to be competitive in Group 4 racing. Therefore, they had commissioned March Engineering to build a new GTP racer for them instead. This was especially beneficial for both BMW and March as March had the experience of developing the March M1, which was a Frankenstein racer powered by a Chevy V8.
Image from BMW M1 Club
Led by Rainer Bratenstein of BMW, March soon developed an ultralight aluminum monocoque chassis dubbed the March 81P along with unique bodywork. The bodywork resembles the Ardex S80, which was registered for 1981 24 Hours of Le Mans, which is not surprising when the developer of the Ardex S80, Max Sardou, was in the developing team.
BMW M1 Procar engine. Image from Canepa.com
The M1C was powered by the 3.5L inline-six from the Procar unit, producing around 480hp and was mated with a 5-speed gearbox. The brake system was also derived from the Group 4 M1s and magnesium spring and damper units were used to reduce weight further. At the end of the day, the car only weighed 899 kilograms, which is still light in modern-day viewpoints.
Image from BMW USA
The M1C debuted on April 26th, 1981, at the six-hour race on Riverside. The car performed well, finishing 6ths, thanks to the lightness and good fuel consumption. However, good fuel consumption also meant that the car was underpowered compared to the Porsches. Despite the M1C pitted as half as less compared to the 935s, the drivers complained that the engine was “too weak” and “looked faster than it felt”.
Image from Autosport via March Archives
In May, the M1C finished 6th in Laguna Seca and even scored the fastest lap in Lime Rock, but the fact that the car was severely underpowered did not change. Soon, the 3.5L inline-six was replaced with the 2.0L turbocharged engine originally from BMW’s Formula 2 race cars. The turbocharged engine easily produced 675~700hp, meaning the new engine would provide tons of power on the tap.
Image from Wheelsage.org
Nonetheless, problems soon began to appear. As the car’s chassis was not originally designed to accommodate the 2.0L engine, numerous mechanical failures followed. The car did not finish in Sears Point, Road America, and Road Atlanta, and even failed to start at 6 Hours of Mosport. The best result of the turbo-powered M1C was finishing 4th at Portland, and it still remains the best result for the car.
Image from Speedgeezers Forum Network
BMW soon called an end to the program for multiple reasons. Firstly, the car performed poorly; the reliable 3.5L unit was underpowered, and the 2.0L unit rarely synchronized with the car. Secondly, BMW did not have enough assets to continue the program, as there were even talk about the company liquidating going on. Finally, BMW’s initial focus was to gain experience in the upcoming Group C, so there was no further reason to continue the GTP program.
Note the fact that the BMW M1C stands out from the crowd of 'conventional' race cars. Image from Racer
The BMW M1C was not a huge success in terms of racing history. Still, it is undeniable that it was one of the most innovative cars on the grid. The new ‘avant-garde’ approach BMW took with IMSA racing was continued with their March 82G vehicles and eventually by the BMW GTP (March 86G Chassis) at the end of the day.
BMW GTP. Image from Supercars.net
At the end of the day…
Although BMW’s IMSA GTP efforts were initially to prepare for Group C, BMW never raced in Group C. It was mostly due to the fact that BMW was not in the best financial situation to pour funds into developing a prototype from a blank sheet of paper. It is especially sad that BMW was unable to be part of the golden era of motorsports due to financial reasons, as the later generation GTP cars proved to be highly competitive.
Image from ULtimatecarpage.com
The BMW GTP was able to produce up to 1,400hp in qualifying form, and even in endurance races the car easily produced 800hp. For example, the Porsche 962 produced 770hp even with their 3.0L engines, while weighing even more than the GTP. With slight modifications, the BMW GTP would have been an astonishing Group C racer, and a serious contender in the championship overall. Of course, the GTP cars and Group C cars differ quite a bit, and it is a jump to assume that the GTP will still be able to be that competitive. Regardless, it is undeniable that BMW’s GTP racers were the cars that had the potential to level the playing field.