The Step1 tuned version of E30 series has non adjustable aftermarket dampers and lowered springs. There are some compromises as the rear subframe chassis spring sockets, can't handle very stiff springs, so the front is more stiff than the rear.
Based on the 1986 model year E30 3-Series, the E30 M3 used the BMW S14 four cylinder engine.The production of the E30 road car was to homologate the M3 for Group A Touring Car racing.
The Sport Evolution model production run of 600 (sometimes referred as EVO3) increased engine displacement to 2.5 L and produced 235 hp (175 kW). Sport Evolution models have 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.
To keep the car competitive in racing following year-to-year homologation rules changes, homologation specials were produced. Homologation (motorsport) 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 wheel 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.