Based on the 1986 model year E30 3-Series, the first M3 was introduced with a 2.3 L I4 S14B23 engine (also known as S14). The engine design was based on various BMW parts: basic block layout from the M10 4-cylinder (found in the 2002 and 320 series) overbored and reinforced to similar specifications of the BMW M88 inline-6. The valve train and head architecture from BMW's M1 and, later, M6 inline-6-cylinder was adopted for aggressive breathing.
In contrast to later M3 iterations, the E30 M3 was campaigned by BMW as well as other racing teams including Prodrive and AC Schnitzer competing in many forms of racing including rally as well as German, British, Italian, Belgian, French, and Australian touring. The production of the E30 road car was to homologate the M3 for Group A Touring Car racing. It was to compete with the "2.3-16V"-model of the Mercedes-Benz W201 190E that was introduced in 1983. In its final years of competition, the 2.5-litre S14 engine in full race trim was capable of over 250 hp (190 kW) naturally aspirated.
The E30 M3 road car
The third car road-going version produced 192 bhp (143 kW; 195 PS) (catalyzed model) and 197.3 bhp (147 kW; 200 PS) (non-catalyzed model). Evolution models (not sold in North America) continued with 2.3 litres but adopted a number of changes including a revised intake camshaft profile and modified exhaust camshaft timing, increased compression, and a more efficient cylinder head intake port design. Larger diameter exhaust header tubes along with the lack of a catalyst contributed to produce approximately 220 hp (160 kW). Other Evolution model changes included larger wheels (16 X 7.5 inches), thinner rear and side window glass, a lighter bootlid, a deeper front spoiler and additional rear spoiler. Later the Sport Evolution model production run of 600 (sometimes referred as Evolution III) increased engine displacement to 2.5 L and produced 238 hp (177 kW; 241 PS). Sport Evolution models had higher lift intake and exhaust camshafts, enlarged front fender openings and an adjustable multi-position front splitter and rear wing. Brake cooling ducts were installed in place of front foglights. An additional 786 convertibles were also produced.
Changes from the standard 3-series
The E30 M3 differed from the rest of the E30 line-up in many ways. The M3, although using the same basic unit-body shell as the standard E30, was equipped with 12 different and unique body panels for the purposes of improving aerodynamics, as well as "box flared" wheel-arches in the front and rear to accommodate a wider track with wider and taller wheels and tires. The only exterior body panels the standard model 3-series and the M3 shared were the bonnet, roof panel, and sunroof.
The E30 M3 differs from the standard E30 by having a 5x120 wheel bolt patern. The E30 M3 had increased caster angle through major front suspension changes. The M3 had specific solid rubber offset control arm bushings. It used aluminum control arms and the front strut tubes where changed to a design similar (bolt on kingpins and swaybar mounted to strut tube) to the E28 5-series. This included carrying over the 5 series front wheel bearings and brake caliper bolt spacing. The rear suspension is a carry over from the E30.
The E30 M3 had special front and rear brake calipers and rotors. It also has a special brake master cylinder.
The E30 M3 had one of two Getrag 265 5-speed gearboxes. US models received an overdrive transmission while European models were outfitted with a "dogleg" version, with first gear being down and to the left, and fifth gear being a direct 1:1 ratio. Rear differentials installed included a 4.10:1 final-drive ratio for US models. European versions were equipped with a 3.15:1 final drive ratio. All versions were clutch-type limited-slip differentials with 25% lockup.
To keep the car competitive in racing following year-to-year homologation rules changes, homologation specials were produced. Homologation rules roughly stated that the race version must reflect the street car aerodynamically and in engine displacement. These include: the Evo 1, Evo 2, and Sport Evolution some of which featured less weight, improved aerodynamics, taller front wing arches (Sport Evolution; to further facilitate 18-inch (460 mm) wheels in DTM), brake ducting, and more power. Other limited-production models (based on evolution models but featuring special paintwork and/or unique interior schemes commemorating championship wins) include the Europa, Ravaglia, Cecotto, and Europameister.
Production of the original E30 M3 ended in early 1992.
The M3s were entered by BMW as well as private racing teams and its wins included the Deutsche Tourenwagen Meisterschaft, British Touring Car Championship, European Touring Car Championship, Australian Touring Car Championship, as well as the one-off World Touring Car Championship title in 1987. The E30 M3 is also a multiple winner of Guia Race, 24 Hours Nürburgring and Spa 24 Hours.
The M3 also saw service as a rally car, Prodrive-prepared examples contesting several national championships and selected rounds of the World Rally Championship between 1987 and 1989. By the latter year, the cars, based on the standard M3, were equipped with six-speed gearboxes and produced 295 bhp. The M3 was not competitive with the four-wheel-drive cars on loose surfaces, but a very effective car on asphalt. Its most notable success was victory on the Tour de Corse in 1987, driven by Bernard Beguin.
Notable publication accolades
In 2004, Sports Car International named the E30 M3 car number six on the list of Top Sports Cars of the 1980s.
In 2007 "Automobile Magazine included the E30 M3 in their "5 greatest drivers cars of all time" under their 25 Greatest Cars of All Time.
- (2.3 L-16v I4) – 195 PS (143 kW; 192 hp) − 0–62 mph: 6.9 s. Top Speed: 146 mph (235 km/h)
- (2.3 L-16v I4) – 215 PS (158 kW; 212 hp) − 0–62 mph: 6.7 s. Top Speed: 149 mph (240 km/h)
- (2.5 L-16v I4) – 238 PS (175 kW; 235 hp) − 0–60 mph: 6.1 s. Top Speed: 154 mph (248 km/h)