1. Development and Production

The initial proposal for the E24 was a based on a BMW E9 3.0 CS with an increased height, in order to make it easier for customers to get into the car. However, Bob Lutz rejected the proposal, eventually leading to the shape of the E24 in its production form.^[1] Unlike its E9 predecessor, the body of the E24 has a B pillar.^[2]

Production started in January 1976 with the 630CS and 633CSi in February 1976. Originally the bodies were manufactured by Karmann, but production was later taken in-house to BMW. Initially, the E24 was based on the E12 5 Series platform.

2. Suspension and Steering

Front suspension consists of MacPherson struts and the rear suspension is independent semi-trailing arms.^[3] In 1982, the front suspension was upgraded to include twin-pivot lower control arms and the geometry of the rear suspension was revised.^[4]

The steering uses a recirculating ball system with power assistance.^[5]

3. Transmissions

Initially, the E24 was available with a 4-speed manual transmission (Getrag 262),^[6] a 5-speed manual transmission (Getrag 265),^[6] or a 3-speed automatic transmission (ZF 3HP22).^[7]

In 1983 the automatic transmission was upgraded to a 4-speed ZF 4HP22.^[8]

4. Engines

Figures are for European specification models, unless otherwise stated. ^[9]

5. M Version

1985 BMW M635CSi. https://handwiki.org/wiki/index.php?curid=1366530

BMW M88/3 engine of the M635CSi. https://handwiki.org/wiki/index.php?curid=1436671

Rear seat beverage chiller. https://handwiki.org/wiki/index.php?curid=1873146

The E24 M635CSi, introduced at the Frankfurt Motor Show in 1983, is the first in the line of M6 models. In 1987, the equivalent model for the North American (U.S. and Canada) market was introduced and badged simply M6.

The M635CSi is powered by a 213 kW (286 hp) version of the M88/3 engine.^[10] The North American M6 vehicle is powered by the detuned 191 kW (256 hp) version of the S38 engine, which has a lower compression ratio and uses a catalytic converter.

Over its production run from 1983 through 1989, 4,088 M635CSi cars were built, 1,767 of which were for the North American market.^[11]

6. Model Year Changes

6.1. 1978

In July 1978, the more powerful 635CSi variant was introduced. The 635CSi featured a close-ratio 5-speed gearbox and a single piece black rear spoiler. The M90 engine's bigger bore and shorter stroke resulted in 160 kW (215 hp) and increased torque in models without a catalytic converter. The aerodynamic changes reduced uplift at high speeds by almost 15% over the other E24 models.^[12]

6.2. 1979

In 1979 the carburetted 630CS was replaced with the 628CSi;^[13] this car had a fuel-injected 2.8L engine taken from the E12 528i. An anti-lock braking system became available as an option.

6.3. 1980

In 1980, the fuel-injection systems changed from Bosch L-jetronic to Bosch Motronic.^[14] The 635CSi central locking system could now be operated from the passenger door and trunk.

6.4. 1982 Facelift

1984–86 BMW 635CSi. https://handwiki.org/wiki/index.php?curid=1599329

In 1982 (model year 1983 in the US), the E24 platform changed from the E12 5 Series to the E28 5 Series, resulting changes to exterior styling, engines, chassis, suspension, electronics and the interior.

The 635 CSi engine was updated to the 3,430 cc (209 cu in) M30B34, which used a smaller bore and longer stroke than the previous 3,453 cc (211 cu in) M90 engine. The 635CSi became available with a wide-ratio 5-speed manual or an automatic.

6.5. 1987

1987-series 635CSi. https://handwiki.org/wiki/index.php?curid=1327653

E24s produced after June 1987 were fitted with ellipsoid headlamps, as per the recently introduced E32 7 Series.^[15] The front and rear bumpers and spoilers were redesigned to use a single design worldwide^[16] (prior to this, models sold in North America used a different design from the rest of the world).

The 635CSi engine was updated to the higher compression M30B35,^[17] which resulted in a power increase of 19 kW (25 hp) for engines with catalytic converters.

7. North America and Japan Model Range

Although other markets offered multiple E24 models, in North America only one model was available at any given time (aside from the M6).

7.1. 630CSi

In 1977, the 6 series was released in the US as the 630CSi. The 630CSi is powered by a fuel-injected version of the carburetted 630CS available elsewhere. This 3.0 litre engine produces 176 hp (131 kW) and 185 lbf⋅ft (251 N⋅m).

7.2. 633CSi

The 630CSi was replaced in September 1977 by the 633CSi.^[18] In United States/Japan specification, the 633CSi was powered by a 181 hp (135 kW) version of the M30B32 engine. Output later dropped to 174 hp (130 kW).

In September 1980 (1981 model year), the manual transmission for US cars was upgraded from a 4-speed to a 5-speed. A 3-speed automatic transmission was optional.^[19]

In September 1982, the major facelift (for all markets worldwide) resulted in the North American and Japanese models being based on the E28 5 Series platform.

7.3. 635CSi

1980's United States market 635CSi. https://handwiki.org/wiki/index.php?curid=1882139

In 1985, the 633CSi was replaced by the 635CSi for the North American Market.^[20] This model uses the M30B34 engine, which produces 182 hp (136 kW) and 214 lbf⋅ft (290 N⋅m) at 4,000 rpm. An L6 "luxury edition" version of the 635CSi was available in North America for the 1987 model year. The L6 featured leather headliner and trim and an automatic gearbox.^[21]

In 1988, the engine was upgraded to the M30B35. This engine has a capacity of 3.4 Litres (despite the model code and the "3.5" inscribed on the intake manifold) and produces 208 hp (155 kW) and 225 lbf⋅ft (305 N⋅m) torque. This upgraded engine resulted in catalytic converter equipped United States models offering similar performance to European models.^[20] Self-leveling rear suspension was added to the 635CSi and M6 features list.^[20]

7.4. M6

1987 BMW M6 (North American Model). https://handwiki.org/wiki/index.php?curid=1385282

In 1987, North America and Japan received their M version of the E24, called the M6. The main difference between the M6 and its European counterpart, the M635CSi, is that the S38 engine is used instead of the M88. Compared with the M88, the S38 has a catalytic converter, the compression ratio reduced to 9.8:1, a double row timing chain, a shorter camshaft duration and a simplified exhaust manifold. The power output for the North American E24 M6 is 256 hp (191 kW), which is 30 hp less than the European M635CSi.^[11]

Standard equipment on the United States market M6 cars included many features which were optional on the European cars, including heated power seats, self-leveling rear suspension, beverage chiller (cooled by an air-conditioning system) between the rear seats, air-conditioning vents for rear seat occupants, sunshade for rear occupants and an 8 speaker premium sound system.^[22]

8. Motorsport

Achievements in championships and series:

• European Touring Car Championship; 3 titles (1981, 1983 and 1986)
• Deutsche Tourenwagen Meisterschaft; 1 title (1984)
• Belgian Touring Car Championship (Group N); 1 title (1984)
• Australian Touring Car Championship; 1 title (1985)
• Australian Endurance Championship; 2 titles (1985 and 1986)
• Australian Manufacturers' Championship; 1 title (1985)
• AMSCAR Series; 1 title (1985)
• European Hill Climb Championship; 1 title (1985)
• New Zealand Touring Car Championship; 2 titles (1985 and 1987)
• New Zealand Benson & Hedges Saloon Car Series; 1 title (1985)
• Nissan-Mobil 500 Series (New Zealand); 1 title (1985)
• Japanese Touring Car Championship; 1 titles (1985)

Race wins:

• RAC Tourist Trophy; 2 wins (1980 and 1984)
• 4h/500 km of Monza; 3 wins (1980, 1981 and 1983)
• Guia Race; 1 win (1983)
• Spa 24 Hours; 3 wins (1983, 1985 and 1986)
• 24 Hours Nürburgring; 2 wins (1984 and 1985)
• Sandown 500; 1 win (1985)

The content is sourced from: https://handwiki.org/wiki/Engineering:BMW_6_Series_(E24)