Although it looked pretty much like a standard E30 3-Series from a distance, the M3 shared only the bonnet with its less-exotic sibling. The most obvious difference was the wider front and rear wings while only the most observant would have noticed the more steeply raked rear window and raised boot, changes made in the interests of aerodynamic efficiency. Necessary chassis improvements included lowered and stiffened suspension, wider wheels, five-stud hubs, ventilated front brake discs, ABS and a limited-slip differential as standard. The gearbox was a five-speed close-ratio Getrag.
Though ultimately not as well known as Alpina, AC Schnitzer replaced the more famous brand at the de-facto factory race team in the late 1970s and 1980s. To capitalize on their success at the race track (including the successful campaigns in the DTM), in 1987 AC Schnitzer launched their first brand-specific model based upon the new E32. That was followed by a more sporty E30-based model, dubbed the ACS3 Sport in 1989. It was available based upon either a normal 3-series, or those with the funds could opt to allow Schnitzer to modify their prized M3. And modify it did; subtle changes outside included revised mirrors, a light change to the rear end and a single-wiper conversion to really channel the DTM spirit. Wheels were either 17″ multi-piece Schnitzer design, or the ever-popular BBS RS model in 16″x8 or 9. As Alpina did, Schnitzer included their own steering wheel (4 options available), a numbered plaque, bespoke suspension 20mm lower than the standard ride height, and a unique rectangular-tipped exhaust.
However, the real treat was the full 2.5 conversion, which really packed some extra power in the S14. Schnitzer brought the total displacement to 2,431 cc – just shy of the 2,467 BMW themselves would produce in the 1990 Sport Evolution. Coupled with a revised DME, the S3 Sport 2.5 produced an impressive 245 horsepower. This was partly due to improved gasflow in the intake and exhaust systems, balancing of the pistons, and increased stroke from the billet steel crank, which delivered more torque and better acceleration than the comparative BMW offering. Working with Bilstein, Schnitzer designed a sport chassis with a 20mm lower ride height, which was very neutral in feel yet very stable at high speeds.
The design of the S3 Sport 2.5 predated BMW’s own 2.5 litre M3, and provided performance comparable to the Motorsport Division’s best efforts. With 245bhp, the Schnitzer could accelerate from 0-100km in 6.7 seconds, and could achieve a top speed of 250 kmh.
Wearing AC Schnitzer plaques on the dashboard and in the engine compartment stamped “0000”, this is an early pre-production prototype of the E30 M3-based Schnitzer S3. Believed to be one of only seven such examples produced and finished in Diamond Black metallic with a grey leather interior, the S3 shows just 73,000 kilometres recorded from new.
Make no mistake, this is a hugely significant motor car, a must-have for the dedicated BMW collector and both a much rarer and more exclusive alternative to the later Sport Evolution model of the M3.