BMW 3 Series (E21)

BMW 3 Series (E21)
Overview
Manufacturer	BMW
Production	June 1975–1983 1,364,039 built
Assembly	West Germany: Munich Malaysia: Kuching (SMI)
Designer	Paul Bracq (1972)
Body and chassis
Class	Compact executive car
Body style	2-door compact sedan 2-door convertible
Layout	FR layout
Powertrain
Engine	1.6-2.0 L M10 4-cyl 2.0-2.3 L M20 6-cyl
Transmission	3-speed automatic 4-speed manual 5-speed manual
Dimensions
Wheelbase	2,563 mm (100.9 in)
Length	4,355 mm (171.5 in) / 4,508 mm (177 in) with US bumpers
Width	1,610 mm (63.4 in)
Height	1,380 mm (54.3 in)
Chronology
Predecessor	BMW 02 Series
Successor	BMW 3 Series (E30)

Interior

The BMW E21 is the first generation of the BMW 3 Series compact luxury vehicle and was produced from June 1975 to 1983. It was initially available as a 2-door sedan, to replace the 02 Series. At launch, all models used carburetted 4-cylinder engines, however fuel injected models were introduced in late 1975 and 6-cylinder engines were added in 1977. A cabriolet body style - manufactured by Baur - was available from 1978 to 1981.

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 their aging 02 Series. Paul Bracq, Director of Design at BMW from 1970 to 1974, is credited with setting the design direction of the E21.

In July 1975, BMW’s Board of Management introduced the 3 Series to the public at the Munich Olympic Stadium.

Design

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 BMW E12 5 Series.

The wedge shape of the two-door model was distinctive, extending all the way to the unusually high rear end. In response to criticism of the tail design, a black plastic trim panel between the tail lights was added. Like many other BMW models, the C-pillar of the E21 features a Hofmeister kink.

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 feature 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.

Engineering

Measuring 4,355 mm (171 in) long, 1,610 mm (63 in) wide, and 1,380 mm (54 in) high, the E21 continued the tradition of the New Class 2-door sedan models. With the wheelbase measuring 2,563 mm (101 in), there was little body overhang in the rear-wheel-drive design. The track measured 1,364 mm (54 in) at the front, and 1,377 mm (54 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).

Initially, a Getrag four-speed manual was the standard transmission fitment. Five-speed overdrive Getrag gearboxes were fitted as standard in 1980, but close ratio 'sport' gearboxes were available at the car's release as an option. Alternatively, purchasers could opt for the ZF 3 HP-22 three-speed automatic transmission.

Models

Model	Years	Headlights	Engine	Power	Torque
315	1981-1983	Single	M10 (M98) carb I4	55 kW (74 hp) @ 5,800 rpm	110 N⋅m (81 lb⋅ft) @ 3,200 rpm
316	1975-1980		M10 (M41) carb I4	66 kW (89 hp) @ 6,000 rpm	167 N⋅m (123 lb⋅ft) @ 4,000 rpm
	1980-1981		M10 (M118) carb I4	66 kW (89 hp) @ 5,500 rpm	144 N⋅m (106 lb⋅ft) @ 3,000 rpm
318	1975-1980		M10 (M118) carb I4	72 kW (97 hp) @ 5800 rpm	143 N⋅m (105 lb⋅ft) @ 4,000 rpm
318i	1980-1981		M10B18 injected I4	77 kW (103 hp) @ 5,800 rpm	148 N⋅m (109 lb⋅ft) @ 4,500 rpm
320	1975-1977	Twin	M10 (M43) carb I4	80 kW (107 hp) @ 5,800 rpm	157 N⋅m (116 lb⋅ft) @ 3,700 rpm
320	1977-1982		M20B20 carb I6	90 kW (121 hp) @ 6,000 rpm	160 N⋅m (120 lb⋅ft) @ 4,000 rpm
320i	1975-1977		M10 (M64) injected I4	92 kW (123 hp) @ 5,700 rpm	175 N⋅m (129 lb⋅ft) @ 4,350 rpm
320i (US)	1977-1979		M10B20 injected I4	81 kW (109 hp) @ 5,700 rpm	152 N⋅m (112 lb⋅ft) @ 4,000 rpm
	1980-1983		M10B18 injected I4	74 kW (99 hp) @ 5,800 rpm	135 N⋅m (100 lb⋅ft) @ 4,500 rpm
323i	1978-1982		M20B23 injected I6	105 kW (141 hp) @ 5,800 rpm	190 N⋅m (140 lb⋅ft) @ 4,500 rpm

315

The 315 was the base model for years 1981 to 1983, fitted with a 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

This 316 was the base model for years 1975 to 1981. It accelerates to 100 km/h in 13.8 seconds and has a top speed of 160 km/h (99 mph).

In 1980 the engine size increased to 1.8 litres, however the model remained badged 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. It accelerates to 100 km/h in 11.9 seconds and has a top speed of 165 km/h (103 mph).

318i

In 1980, the carburetted 318 was 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 320 was a mid-range model, powered by a 2.0 litre engine using a Solex 2-barrel downdraft carburettor. It accelerates to 100 km/h in 11.2 seconds and has a top speed of 170 km/h (106 mph).

320i

The fuel injected 320i was released in late 1975. It accelerates to 100 km/h in 9.9 seconds and has a top speed of 182 km/h (113 mph).

US models are fitted with a thermal reactor as a pollution control device. The 2.0 litre US model (1977-1979) accelerates to 100 km/h in 10.5 seconds and has a top speed of 165 km/h (103 mph). The 1.8 litre US 320i and 320is models (1980-1983) accelerate to 100 km/h in 11.1 seconds and have a top speed of 169 km/h (105 mph).

320/6

M20 six-cylinder engine

The 320/6 replaced the 320i. It uses a six-cylinder engine with a Solex 4-barrel downdraft carburetor. It accelerates to 100 km/h 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 1979. It is powered by a 2.3 litre six-cylinder engine using K-Jetronic fuel-injection. It accelerates to 100 km/h in 8.7 seconds and has a top speed of 200 km/h (124 mph).

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.

Due to American regulations, the following changes were required:

• larger front and rear "diving board" bumper bars
• 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.

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 4-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 featured the M10 4-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 straight-6 M20 engines (which were initially called "M60").

The 4-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.

The 320is model (US only) was released in 1980 using a 1.8 litre version of the M10. The "S Package" featured 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 and a limited color palate of white, silver or black. Just 2,500 320is's were produced.

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 cabriolet

Baur TopCabriolet

A cabriolet conversion was offered by Karosserie Baur GmbH, based on regular E21 models. The cabriolet conversion was composed of a targa roof and an independent rear soft-top. Production of the Baur TopCabriolet began in 1978, and were sold via the BMW dealership network.

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

Motorsports

The Group 5 version of the BMW 320, introduced in 1977 as a replacement to the already obsolete BMW 3.0 CSL and became nicknamed as the Flying Brick in reference to the blocky bodyshape, was powered by a Formula Two engine that was tuned to 225 kW (306 PS) 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.

Other than the main factory team and McLaren who ran the IMSA operation in the US, the car was notably used by the BMW Junior Team, who had the likes of Manfred Winkelhock, Eddie Cheever, and Marc Surer as drivers. They would help to win the 1977 Deutsche Rennsport Meisterschaft and would later go into Formula One. The 320 won its first race, at Zolder in 1977 with Surer at the wheel.

The car was also used to win the Macau Guia Race in 1981 and 1982.

Further reading

• Jeremy Walton (2001). BMW 3-Series Collectors Guide: Generation 1 and 2 including M3. Motor Racing Publications. ISBN 1-899870-55-5.
• R.M. Clarke (1990). BMW Series 3 - 4 Cylinder Cars Gold Portfolio. Brooklands Books. ISBN 1-85520-149-6.