Based on the BMW 3-Series model E21, the tuner-manufacturer Alpina created two of their special versions: the B6 2.8 and the C1 2.3. The B6, produced from November 1978 to January 1983, was derived from the 323i and was equipped with a 2788cc engine (6-cylinder in-line, type M30). Produced in 533 units, the B6 had a power of 200 then 218 horsepower.