Buick Legends - Best of Buick ever
While in most markets several E24 versions were usually available, markets with strict emission control regulations received only a single model (except for the M6 that was later offered additionally). This meant that in North America and Japan, BMW offered the following models :
1988 BMW M6 630CSi (MY 1977 through 1978½)633CSi (MY 1978½ through 1984)635CSi (MY 1985 through 1989)L6 (MY 1987 - Luxury Edition 635CSi NA-only)M6 (MY 1987 through 1989) In 1977, the 6er was released in the US as the 630CSi. This was a fuel-injected version of the carburetted 630CS available elsewhere. Its 3-litre engine developed 176 horsepower (131 kW) and 185 ft·lbf (251 N·m) of torque. In mid-model year 1978 the 630CSi was replaced by the 633CSi. US/Japan specification 633CSi cars had the M30 3.2 litre 181 hp (135 kW) engine until 1984. In 1985 the car was renamed 635CSi, displacement was increased to 3.4 litres and horsepower increased slightly to 182 hp (136 kW). The big difference, however, was torque. Whereas the 3.2 litre had 195 ft·lbf (264 N·m) at 4,000 rpm, the 3.4 litre powerplant managed 214 ft·lbf (290 N·m) at 4,000 rpm. From model year 1983, North American and Japanese versions benefitted from the technical revisions and changes to the interior introduced elsewhere in spring or summer 1982. Its chassis was now based on the E28 and no longer on the E12. The front and rear suspension was also revised. Later a self-levelling rear suspension was added to the 635 CSi and M6 features list in 1988.
The US received its own M series E24 in 1987 called the M6. The S38 powerplant found in the US model had several modifications from the M88 powerplant in the European model, most notably: a double row timing chain, modified cam tray, different valve lengths, a slightly different cam profile, less elaborate exhaust manifold (rather than full headers), Bosch X5DC copper spark plugs (instead of Bosch Silver plugs on the M88) and the introduction of an oxygen sensor for the EFI. These changes coupled with the introduction of a catalytic converter for emission regulations reduced the output to 256 hp (191 kW). The US model also included a variety of options not found on the earlier European models, to include: heated power seats, sport tuned self-levelling rear suspension, A/C cooled ice box between the rear seats, A/C vents for rear seat occupants, sunshade for rear occupants and an 8 speaker "premium" sound system.
In 1988, the US E24 was now available with the newest version of the M30, the 3.4L (first used in the E32 735i). Even though the intake manifold states 3.5 it's technically a 3.4 (3430cc) like the previous 3.4. This engine had an increased compression ratio, and updated Motronics/DME. The result was 208 hp (155 kW) and 225 ft·lbf (305 N·m) torque. In effect, this engine was identical to the catalyzed version newly available in Germany and other markets.
