BMW 3 Series (E21)

BMW 3 Series (E21)
Overview
Production	June 1975 – December 1983
Assembly	Germany: Munich
Body and chassis
Class	Compact executive (D)
Body style	2-door sedan 2-door convertible
Layout	Rear-wheel drive
Powertrain
Engine	1.6–2.0 L M10 I4 2.0–2.3 L M20 I6
Transmission	4-speed manual 5-speed manual 3-speed automatic
Dimensions
Wheelbase	2,563 mm (100.9 in)
Length	4,355–4,508 mm (171.5–177.5 in)
Width	1,610 mm (63.4 in)
Height	1,380 mm (54.3 in)
Curb weight	1,020–1,180 kg (2,250–2,600 lb)
Chronology
Predecessor	BMW 02 Series
Successor	BMW 3 Series (E30)

Interior of post-1979 facelift

The BMW E21 is the first generation of the BMW 3 Series compact executive cars, which were produced from June 1975 to 1983 and replaced the BMW 02 Series.

Initial models were produced in a two-door sedan body style with four-cylinder petrol engines. Fuel-injected engines were introduced in late 1975 and 6-cylinder engines were added in 1977. A cabriolet body style – manufactured by Baur— was produced from 1978 to 1981.

There was no BMW M3 model for the E21 generation, but several limited edition models were produced based on the model with the largest engine, the six-cylinder 323i.

The E21 was replaced by the E30 3 Series in 1982.

Development

Under the direction of its majority (51%) shareholder, Herbert Quandt, BMW decided upon a replacement for the ageing BMW 02 Series.

In July 1975, BMW's Board of Management introduced the E21 to the public at the Munich Olympic Stadium.

Styling

The frontal view of the new car was dominated by the BMW trademark kidney grille standing out clearly from the radiator cover. The styling of the new car bore a resemblance to the E12 5 Series which was in production as the E21 was introduced. Like many other BMW models, the C-pillar of the E21 has a Hofmeister kink.

Paul Bracq, Director of Design at BMW from 1970 to 1974, is credited with setting the design direction of the E21.

The BMW E21 is according to the Design Museum London one of "fifty cars that changed the world".

Interior

The cockpit design of the E21 marked the introduction of a new design concept, with the center console and central dashboard area angled towards the driver. This has become part of BMW's interior design philosophy for many years. As a sign of passive safety, all edges and control elements within the interior were rounded off and padded.

Engines

Model	Years	Headlights	Engine	Power	Torque
315	1981–1983	Single	M10 (M98) carb I4	55 kW (74 bhp) at 5,800 rpm	110 N⋅m (81 lb⋅ft) at 3,200 rpm
316	1975–1980		M10 (M41) carb I4	66 kW (89 bhp) at 6,000 rpm	123 N⋅m (91 lb⋅ft) at 3,000 rpm
	1980–1981		M10 (M118) carb I4	66 kW (89 bhp) at 5,500 rpm
318	1975–1980		M10 (M118) carb I4	72 kW (97 bhp) at 5800 rpm	143 N⋅m (105 lb⋅ft) at 4,000 rpm
318i	1980–1981		M10B18 injected I4	77 kW (103 bhp) at 5,800 rpm	148 N⋅m (109 lb⋅ft) at 4,500 rpm
320	1975–1977	Twin	M10 carb I4	80 kW (107 bhp) at 5,800 rpm	157 N⋅m (116 lb⋅ft) at 3,700 rpm
320/6	1977–1982		M20B20 carb I6	90 kW (121 bhp) at 6,000 rpm	160 N⋅m (118 lb⋅ft) at 4,000 rpm
320i	1975–1977		M10 (M64) injected I4	92 kW (123 bhp) at 5,700 rpm	172 N⋅m (127 lb⋅ft) at 4,350 rpm
320i (US)	1977–1979		M10B20 injected I4	81 kW (109 bhp) at 5,700 rpm	152 N⋅m (112 lb⋅ft) at 4,000 rpm
	1980–1983		M10B18 injected I4	74 kW (99 bhp) at 5,800 rpm	135 N⋅m (100 lb⋅ft) at 4,500 rpm
323i	1978–1982		M20B23 injected I6	105 kW (141 bhp) at 5,800 rpm	190 N⋅m (140 lb⋅ft) at 4,500 rpm

315

The BMW 315 is easily distinguishable from other E21 models by its headlamps: Instead of halogen bulbs, it has R2 twin-filament bulbs

The 315 was the base model for years 1981 to 1983, with a 55 kW (74 bhp) version of the 316's 1.6-litre engine tuned for fuel economy. It accelerates to 100 km/h in 14.8 seconds and has a top speed of 154 km/h (96 mph).

316

BMW 316

The 316 was the base model for years 1975 to 1981, fitted with a 1.6 L (98 cu in) M10 engine producing 73 kW (98 bhp). It accelerates to 100 km/h (62 mph) in 14 seconds and has a top speed of 160 km/h (99 mph).

In 1980 the engine size increased to 1.8 litres (after the 318 carburetor version was discontinued), while the model badge remained as "316". Acceleration to 100 km/h was reduced to 12.5 seconds and top speed increased to 167 km/h (104 mph).

318

The 318 was a mid-range model that was powered by a carburetted four-cylinder engine. It accelerates to 100 km/h in 12 seconds and has a top speed of 165 km/h (103 mph).

318i

In 1980, the carburetted 318 was dropped and replaced by the fuel injected 318i. It accelerates to 100 km/h in 11.5 seconds and has a top speed of 173 km/h (107 mph).

In Sweden, the 318i was badged 320i and had twin headlights.

320

320 model with twin headlights

The initial 320 model was powered by a four-cylinder engine using a Solex 2-barrel downdraft carburettor. It accelerates to 100 km/h (62 mph) in 11.5 seconds and has a top speed of 170 km/h (106 mph).

320i

The 320i was released in late 1975. It has a continuous port injection system (Bosch K-Jetronic) instead of a carburetor. It accelerates to 100 km/h (62 mph) in 10.5 seconds and has a top speed of 180 km/h (112 mph).

320/6

M20 six-cylinder engine

In 1977, the 320 model switched from the BMW M10 four-cylinder engine to the BMW M20 straight-six petrol engine. Although they remained badged as "320", the six-cylinder model is often referred to as "320/6". The engine uses a Solex 4-barrel downdraft carburetor. The 320/6 accelerates to 100 km/h (62 mph) in 10.0 seconds and has a top speed of 180 km/h (112 mph).

323i

The 323i was the top E21 model following its introduction in 1977. It is powered by a 2.3-litre six-cylinder engine using Bosch K-Jetronic fuel-injection. It accelerates to 100 km/h (62 mph) in 8.7 seconds and has a top speed of 200 km/h (124 mph).

Transmissions

• 3-speed ZF 3HP22 automatic (318 and 320)
• 4-speed Getrag 242 manual
• 5-speed Getrag 245 manual, with either an overdrive fifth gear or close-ratio gearing (the latter available from 1976).

Chassis and suspension

With a wheelbase measuring 2.6 m (102 in), the lengths of the overhanging front and rear bodywork was minimal. The track measured 1,364 mm (53.7 in) at the front, and 1,377 mm (54.2 in) at the rear.

The suspension incorporated rack and pinion steering and MacPherson strut suspension at the front, and semi-trailing arm type independent suspension at the rear. The rear suspension design causes camber changes, which can introduce "snap oversteer" at the handling limits. The power assisted brakes were discs on the front wheels, while the rear wheels had drum brakes (except the 323i model which had discs all round).

Model year changes

At the E21's release, three models were available: with 316 (1.6-litre), 318 (1.8-litre) and 320 (2.0-litre) versions of the BMW M10 four-cylinder engine. To differentiate between models, the 320 model came with dual headlights, while the 316 and 318 had single headlights.

1975

The fuel-injected 320i was introduced at the end of 1975. It has the M10 four-cylinder engine with Bosch K-Jetronic fuel injection, and a limited slip differential was available as an option.

1977

At the 1977 International Auto Show in Frankfurt, BMW unveiled its new variants of the E21, featuring the new BMW M20 six-cylinder engines (which were initially called "M60").

The four-cylinder 320 model was replaced with the 320/6, featuring a 2.0 litre version of the M20 engine. The new range-topping 323i model was introduced, featuring 2.3 L with 105 kW (141 hp), which gave the 323i a top speed of 200 km/h (124 mph). The braking system was also upgraded, with the 323i featuring disc brakes on all wheels. Options include power steering, a 5-speed close-ratio 'dogleg' sport gearbox, and 25% limited slip differential.

1980

For the 1980 model year, the four-cylinder models were upgraded: the 1.8 L carburetted M10 unit was revised to produce 66 kW (89 hp) and entered the market in the updated 316, while a fuel-injected version of the 1.8 L M10 was introduced in the 318i model (which replaced the carburetted 318 as the mid-range model). This fuel-injected 1.8 L M10 was also sold in Sweden with 320i badging (with a higher level of standard equipment to distinguish it from the 318i), because the 320/6 was never certified for sale there.

1981

The economy model 315 was introduced as a reaction to the second "oil crisis" in late 1979. More spartan than the other E21 models, it was the last E21 to be built and produced alongside the early E30 models.

Baur TopCabriolet

Baur TopCabriolet

A cabriolet conversion was offered by Karosserie Baur, called the TopCabriolet. It consisted of a targa roof and an independent rear soft-top. Production of the TopCabriolet began in 1978, and were sold via the BMW dealership network.

All Baur models included the BMW warranty. A total of 4,595 vehicles were manufactured before production ended in 1981.

North American models

North American 320i (front)

North American 320i (rear)

The E21 was sold in the United States from model years 1977 to 1983 as the four-cylinder 320i and 320is. Six-cylinder models were not sold in America, because the E21 versions of the M20 engine did not meet U.S. emissions regulations at the time. The 320i models sold in the United States have a thermal reactor as a pollution control device.

From 1977 to 1979, the U.S. models are both powered by a 2.0 L (122 cu in) fuel-injected version of the M10 four-cylinder engine. In 1980, the M10 engine was downsized to 1.8 L (110 cu in), resulting in a 100 km/h (62 mph) acceleration time of 11.1 seconds and a top speed of 169 km/h (105 mph).

Due to American regulations, the following changes were required:

• larger front and rear "diving board" bumper bars, which increased the car's overall length by 16 cm (6 in) to 4.5 m (177 in).
• sealed beam headlights, larger indicator lights and side reflectors
• speedometer in miles-per-hour
• fuel gauge markings changed from litres to "full, ½, reserve"
• a detuned version of the M10 engine, initially using a thermal reactor to control exhaust emissions
• in 1980, the engine was downsized from 2.0 L to 1.8 L and the thermal reactor was replaced with a catalytic converter.

In 1980, the 320is model was released in the United States, powered by a 1.8 L (110 cu in) version of the M10 four-cylinder engine. The "S Package" had Recaro sport seats, upgraded suspension components that included a rear anti-roll bar and a larger front anti-roll bar, a 5-speed transmission and limited-slip differential, cross-spoke alloy wheels, a larger and more extensive tool kit, a dual operation manual sunroof, an AM/FM Blaupunkt radio with cassette player, fog lights, a 3-spoke leather-wrapped steering wheel and leather shift knob, a front air dam, a "delete" of the alphanumeric 320i markers on the rear trunk lid, a "delete" of factory air conditioning; an central-dash storage area where A/C controls were normally mounted, and a limited color palette of white, silver or black. Just 2,500 320is's were produced.

Production

Production of the E21 began in June 1975 and finished in December 1983. Total production estimates vary between 1,359,444 and 1,364,039 cars.

The E21 was produced at the BMW plant in Munich, Germany. Models sold in Malaysia used complete knock-down kits produced in Germany, which were assembled in Kuching, Malaysia.

Motorsports

The Group 5 version of the BMW 320 introduced in 1977 as a replacement to the BMW 3.0 CSL, nicknamed the Flying Brick in reference to the blocky bodyshape, was powered by a Formula Two engine that was tuned to 225 kW (302 bhp) by BMW Motorsport. The car was developed in only just over 12 weeks, without technical drawings. BMW Motorsport engineers simply carried out the modifications directly, with the car progressively taking its final shape.

The Group 5 320 was also used by the McLaren team in the American International Motor Sports Association series. It was also used by the BMW Junior Team, whose drivers included Manfred Winkelhock, Eddie Cheever, and Marc Surer. The 320 won its first race, at Zolder in 1977 with Marc Surer at the wheel. It also won the 1981 and 1982 Guia Race of Macau.