Das Gosser Beer E9 CSL Tribute
By Sandy Washburn
My 1972 BMW 3.0 CSL “Batmobile” tribute car was built about 18 years ago by Rolf Humberg of Burlington VT. Rolf ran it for many years at Watkins Glen until my purchase in 2019. Since then the car has undergone continuous improvement while trying to stay period correct. This has been due in no small part to the engineering skills of my son Bill and his friend Franz Diebold.
Mechanically the car was already in excellent shape with a European M6 sourced M88/3 24- valve race prepared engine with a Metric Mechanic prepared head with shimless buckets, Rally intake cam, and forged high-compression pistons which had been recently rebuilt by the original owner. VAC Motorsports in Philadelphia has since installed proper M88/S38 heavy weight valve springs together with stronger factory valves properly seated with full head machining. While the engine was apart, my son replaced the main bearings with coated bearings from VAC. He replaced the rod bearings two years ago with similar bearings. VAC also supplied a special steel head gasket which they use on competition engines.
My son also installed a modern Life Racing engine computer, wasted spark ignition, modern Siemens Deka fuel injectors, Cosworth Omega data display and Stack ST400 tach for track use. He also built a System 25 sealed engine wire harness for the car. The chassis harness uses a Mclaren Electronics solid state relay box for all engine power electronics and a Bussman relay box for chassis duties. The set allows tuning from a remote location.When we were at Watkins Glen event in July 2019, a professional tuner familiar with the M88 engine and LIFE Racing computer helped tune the car further, eventually finding about 50 horsepower.
My son also fabricated a custom stainless twin pipe side exhaust system replicating the system in the 1975 Sebring-winning factory prepared BMW 3.0 CSL models, which provides the sound unique to those competition models. The car already had the desirable Euro long tube exhaust manifold. The transmission is a close ratio dog leg Getrag 265 (which enables plenty of upgrade paths to close ratio gearsets in the future), a triple plate Tilton clutch, AKG works type shifter adapted from an E30 and a plated LSD (75% lock) unit in the OEM E9 differential housing.The car had a coil over front suspension when I purchased it. The shocks are Bilstein but I am still not sure about the springs. The front shock tower construction of the stock E9 is quite strong but a strut tower cross brace is needed when power is added. The coil over system also provides for camber adjustment. The car has CCW two piece wheels, 10.5 x 17 in front and 12.5 x 18 in the rear. I have also installed an OMP full containment race seat and Schroth six point harness, as well as a new fire suppression system and Fuel Safe fuel cell. The car already had a well designed fuel system with lift pump, surge tank and Bosch 044 high pressure system.
Upon purchase it was immediately apparent that although the paint and decals were very tired, the body was totally rust free with an excellent roll cage. I have since repainted the car dark green in tribute to the unique 1977 Gosser Beer BMW Alpina CSL race car with appropriate Alpina decals.
Owning a race prepared CSL has been a long term goal since I saw them win the Sebring 12 hour race in 1975. The stewardship purchase of this CSL tribute is more than I could have ever hoped for. With over 300 rear wheel HP and a curb weight of 2500 pounds, modern Wilwood disc brakes, and Bilstein shocks, this car performs as well as the historic 1975 Group 4 factory prepared BMW CSL models did in the USA IMSA series. It is a joy to drive at Watkins Glen, Lime Rock and Club Motorsports, which I anticipate doing for many more years. The car is now strictly used in HPDE track days with BMW CCA and other clubs, which is a lot safer option at my advanced age than true vintage racing.
