(from Wikipedia, the free encyclopedia) 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 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 bumper 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.
Specifications. Body : length/width/height/wheelbase –cm (in) : 435/168/137/257 (171.1/66.1/53.9/101); weight : 1250 kg (2770 lbs).
Engine : 4-cylinders 2303 cc (141 ci), front-mounted, 16 valves (4 each cylinder)), Bosch injection, 5-speed, manual, rear-wheel drive. power : 200 bhp @ 6750 rpm. Top speed : 235 km/h (146 mph); 0-60 mph : 7,5 sec.