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Octane Press January 22, 2019 3:57 AM
As we build up to this year’s Rolex 24 at Daytona, RACER.com is pleased to bring you a series of excerpts from IMSA 1969-1989 by Mitch Bishop and Mark Raffauf. The soon-to-be-released inside history of IMSA’s first two decades is currently available for pre-order from Octane Press, and as a RACER.com reader, you can get $10 off by applying the discount code RACER19 at checkout. Click here for ordering information, and look for the final except on Thursday.BMW of North America’s racing group was established in 1975 in an effort to support the company’s growth in the lucrative US performance car market. Unfortunately, the company did not have an IMSA championship to show for the investments in the BMW 3.0 CSL and the turbocharged BMW 320i. With just one or two cars pitted against a host of Porsches, the odds were not in their favor. The tube frame M-1 Procar crushed the GTO competition in 1981 but was underpowered in IMSA’s top class.
Something had to be done to narrow the gap. Former SCCA executive Jim Patterson, who took over the BMW North America racing program in 1978, saw the newly minted GTP rules as a way to get back in the game. Working with partner March Engineering, a unique new prototype was unveiled in early 1981 that would become the basis for a long, successful supply of GTP cars to the IMSA field from the British company.
Designed by French aerodynamics expert Max Sardou and BMW engineer Raine Bratenstein, the car was dubbed the BMW M-1/C. It was built around a March Engineering aluminum monocoque and featured two distinctive pontoons at the front that were designed to channel airflow to both the radiators and twin ground-effects tunnels for maximum downforce.The car was initially fitted with a 3.5-liter, six-cylinder, normally aspirated BMW engine, and entered for the first time at the Riverside 6 Hours in April 1981 with David Hobbs and European endurance veteran Marc Surer at the wheel. Featuring sponsorship livery from Kenwood audio, the pair finished a credible sixth place, albeit eleven laps down to the winning 935 piloted by Fitzpatrick and Busby.
A lone BMW M-1/C is swamped by a host of Porsche 935s at the start of the 1981 Riverside Camel GT race. The M-1/C would go on to finish sixth, eleven laps down from the winning Porsche 935 of John Fitzpatrick/Jim Busby. Image by Kurt Oblinger
A week later at Laguna Seca, Hobbs placed sixth again, this time one lap down to the new Lola T-600 with Brian Redman at the wheel. Although down on power, Hobbs managed to put the car on the front row at both Lime Rock and Mid-Ohio. The dawn of the GTP era had arrived.The first few races proved the M-1/C had real potential and the decision was made to further develop the chassis and engine. The long-term plan was to install the 1.5-liter turbocharged BMW motor being developed for Formula One, but that engine wasn’t ready and would never be used in the March. Instead, the team force-fit the same turbocharged 2.0-liter, four-cylinder engine that had been used successfully in the McLaren-engineered BMW 320i program. Since the M-1/C had not been designed for that power plant, it required a cooling work-around for a motor that produced 600 to 675bhp with the boost turned up.Results were mixed after the change. The new engine debuted at Sears Point in August. The car was fast and competitive, but ultimately unreliable. A fourth place at Portland would turn out to be the team’s best finish. Despite stating long-term commitments early on, BMW once again left IMSA racing at the end of the year, this time to focus on its Formula One program. Even with this setback, March Engineering continued to develop the chassis for 1982 when an upgraded version dubbed the March 82G was offered to customer teams. That decision turned out to be a good one for both March and IMSA, as it provided a well-developed customer chassis for different engine options.The biggest story of the 1981 season centered on Lola. After IMSA GTP rules were published in early 1980, Brian Redman approached Lola Cars founder Eric Broadley with the idea of building a car for the new class. In addition to being one of the top drivers of the time in any equipment, Redman was also selling Lola cars for Carl Haas in the United States and was intrigued by the new rules; he saw an opportunity for a customer car and a chance to come out of retirement.