1975 BMW 3.5 CSL

BMW built five examples of the 3.0 CSL for North America in the 1975 & 1976 IMSA Camel GT Series in Group 4 specifications. Four examples were actively raced. They made their racing debut at the 24 Hours of Daytona in February of 1975 and were the most highly developed version of the CSL.

The BMW CSL (for Coupe Sport Leicht) had proven to be a worthy contender in the Group 2 through Group 5 European Touring Car Championship (ETCC), and BMW hoped it could be used to establish a presence in American motorsports. Introduced in the early 1970s, the CSL was the first product of BMW Motorsport GmbH, a subsidiary of BMW dedicated to motorsports development. Currently, it is now known as the M division.

The M49 engine with DOHC and 24 valves had been developed for the 1974 season. It later increased to 3.5-liters in preparation for LeMans and became the M49/2. The 3.5 CSL had mechanical fuel injection, crankshaft triggered ignition, slide throttle induction, 4 valves per cylinder, and 475 horsepower at 8500 RPM. Aerodynamic features included a front air dam, roof and rear wings (which gave it the 'Batmobile' nickname), and 'fences' on the front fenders. In comparison to the other CSL's, the 3.5 CSL had much wider fender flares and deeper front valence. The 1975 examples can be identified by the absence of 3/4 windows, which were installed for the 1976 season.

BMW lost the Camel GT Challenge trophy to Brumos Racing Porsche RSR by only a few points in 1975. The CSL won seven IMSA races outright with Hans Stuck responsible for four of those victories. They have proven the BMW could race against the best America had to offer. For the following season, the fourth generation Group 5 rules were introduced by the FIA which allowed for more freedom and development than IMSA or Group 4. This meant some of the ineligible 3.0 and 3.2-liters cars from the ETCC could be modified to race up until 1979. Among the distinguishable features of the Group 5 cars are the protruding front spoilers as seen on the Le Mans cars, and a longer rear wing. Power was from the 3.5-liter M49 24-valve engine. Among the highlights for the 1976 season was a victory at the 24 Hours of Daytona by drivers Peter Gregg and Brian Redman.

by Daniel Vaughan | Feb 2020