Ferrari 275 GTB Competizione Speciale
For the 1965 racing season, 4 lightweight 275 GTB Competizione Speciales were built and equipped with 250 LM engines.
For the 1966 season, Ferrari decided to build 12 lightweight 275 GTB/C cars, they were constructed between the end of the 275 two-cam production run and the start of the 275 four-cam production run; even though they very much resembled the road-going 275 GTB, not one body panel was the same and underneath very little of the road car remained.
Mauro Forghieri designed a special super-lightweight steel and aluminum version of the 275 GTB chassis. A regular suspension was fitted, but it was made slightly stiffer by the addition of extra springs. Scaglietti bodied the chassis with an ultra thin aluminum body; the panels were about half as thick as the ones used on the GTO and the Cobra - even leaning on the 275 GTB/C would dent the body; the entire rear section was reinforced by fiberglass to prevent it from flexing at the slightest impact. In all, this focus on saving weight made a difference of over 150 kg (331 lb) compared to the alloy bodied road cars.
Like the four 'Competizione Speciales', the 275 GTB/C was powered by the 250 LM engine. Somehow Ferrari 'forgot' to mention to the governing body that the 275 GTB had a six carburetor option, so only a three 'carb' engine could be homologated. Specifically for the 275 GTB/C, Weber constructed the 40 DF13 carburetor of which three would replace the six 38 DCNs found on the 250 LM. The rest of the drivetrain was similar to the 275 GTB, but strengthened slightly.
Two of the twelve built were sold for street use. Unlike the race cars, these street cars were fitted with alloy wheels shod with Pirelli tires. Competition cars were fitted with special Borrani wire wheels, shod with Dunlop's latest racing tires. It was this combination that would prove to be the weak spot of the 275 GTB/C; the tires had so much grip that they could overstress and break the spokes on the wheels. After the 275 GTB/C, no competition Ferrari would be fitted with wire wheels again.
A British-entered 275 GTB/C finished 8th overall, gaining class victory in the 1966 24 Hours of Le Mans.
Source: Wikipedia, 2014
Photo Credit: RM Auctions