This is one of three new cars Alpina introduced at the IAA 1978. The two other cars were based on the 5- and 6-series but this one is based on the 323i, BMW´s top of the line model of the first 3-series generation. The production started in March 1978 and ended in January 1983. In August 1981 the car went through some modifications. A total of 533 cars were built.
To improve the E21's suspension, Alpina used Bilstein springs in front with gas-pressure shocks and shorter and stiffer Ahle springs. At the rear, Alpina used gas-pressure shocks from Bilstein. The 15" Alpina alloy-wheels are 7" wide at the rear with 205/50 tires. The front wheels were 6" wide with 195/50 tires. For extra stopping, the front brakes were ventilated, drilled discs.
B6 2,8 is based on the 323i. But the engine isn´t based on the 2,3 litre six. It is based on the 2,8 litre six from 528i. In standard shape that engine delivers 177 bhp which is a lot, especially in the 3-series pretty small and light body. But Alpina wasn´t satisfied with that so they modified the engine to give even more power and to be more frugal too. They fitted forged Mahle-pistons and modified the combustion chambers to increase the compression. They have also fitted a new fuel injection system, made by Zenith-Pierburg-DL. Those are the major changes but there are also some other minor changes that help to increase the power. The engine now produces 200 bhp and has a torque of 248 Nm. The 323i´s original four-speed gearbox is changed to a Getrag five-speed unit. In August 1981 the B6 received a more highly-developed induction system which made the 2,8 litre six produce 218 bhp, exactly the same as BMW´s 3,5 litre engine. That made the car even faster.
The B6 is even by today´s standards a very fast car. Alpina claimed 7,5 seconds from 0-100 km/h. But independent road testers found the time to be closer to 6,9 seconds. The B6 also has a top speed of around 225 km/h. In performance the B6 could compete with much more expensive sports cars. For the 218 bhp B6, Alpina claimed a 0-100 km/h time of only 7 seconds and a top speed of 229 km/h.
