Model history: Anticipating a war, Alfa Romeo hid their competition cars and production moulds before manufacturing would be suspended. When the hostilities of the Second World War were over, Alfa Romeo only needed to dig up the cars and moulds to immediately continue production. This gave the Milanese manufacturer an apparent edge over the competition, but the lack of high quality materials hampered production. One of the competition cars concealed was the Alfa Romeo 158 Grand Prix racer, which took the first Formula 1 Championship in 1950.
Production of the 6C 2500 road car recommenced early in 1947. Being the only luxury supercar available, the 6C 2500 SS was the most expensive new car. With the production 6C 2500 being similar to the pre-War model, it would have not been a surprise if the competition version would be similar to the Corsa of 1939 and 1940, but Alfa Romeo had other plans. In 1946 work was started on a new Berlinetta racer based on the Mille Miglia 2nd place finishing 6C 2500 SS Corsa.
Of the many modifications carried through, the shorter wheelbase and revised rear suspension are the most obvious. Another 20 mm was cut off the already short 6C 2500 SS, to save weight and increase the car's cornering ability. The all-round independent suspension was retained, but the rear torsion bar / friction damper setup was replaced by a single transverse leaf spring and twin hydraulic dampers. Engine performance was also increased, the six cylinder engine now produced a factory quoted 145 bhp, opposed to the 120 bhp of the pre-War racer.
The short wheelbase chassis was bodied in the factory and was designed with aerodynamics in mind only. The ultra low 'drop snoot' nose and elongated driver's compartment made the 6C 2500 Competizione's body a very efficient one; top speeds of over 200 km/h were reached in testing. The grill was shaped unlike any of those seen on previous Alfa Romeo road-racers, but it did resemble that of the 158 Grand Prix racer. The rear-end shared similarities with the Touring bodied coupe version of the 1939 Corsa.
Due to the shortages right after the War, it took until 1948 before the 6C 2500 Competizione made its racing debut. In the few races organised, notable results were achieved. Highlight of the Competizione's sporting career were the two third place finishes in the Mille Miglia of 1949 and 1950, and the 1950 Targa Florio victory. A third car was constructed in 1950 and fitted with the 3 litre engine also found in the 6C 3000 Saloon. It made only one appearance, but with the 6C 3000 prototype it was quickly abandoned.
After the first two Formula 1 Championships in 1950 and 1951, sights were once more set on sportscar racing. Although the 6C 3000 made only one appearance, it formed the base for Alfa's 1953 contender. Dubbed 6C 3000 CM (Competizione Maggiorata), the new car used a similar six cylinder engine, but now displacing just under 3.5 litre. Compared to the 6C 2500 of 1948, power had doubled, making the CM a strong contender for the victory in the all important Mille Miglia. Four Coupes and two Spiders were constructed.
Competition was strong from Ferrari's hugely powerful sports cars and the sophisticated Lancias designed by Vittorio Jano. The highlight of the Coupe's career was a second place finish in the 1953 Mille Miglia, behind the victorious Ferrari. A Spider scored a win in the 1953 Supercortemaggiore. Alfa Romeo campaigned a Spider equipped with disc brakes as late as 1955, but it proved no real match for the strong competition.
This is the first of the two Colli Spider bodied 6C 3000 CMs constructed. The pictured Spider was driven to victory in the Supercortemaggiore race at Merano in 1953 by Juan Manuel Fangio; the type's only win. The second car used a modified, shorter chassis and three-litre engine and was prepared for the 1954 Supercortemaggiore. Sadly the short-wheelbase car was destroyed during its first test and before it could be immortalized in pictures.
Fangio's winning machine was retained by the factory and served as a test-bed for disc brakes in 1955. Today, the car is still owned by Alfa Romeo, who show the car in their excellent Museo Storico as well as at various events around the world. It is seen above during the 2006 Retromobile show and the 2009 Goodwood Festival of Speed.