GTA, The derivatives -2 part
During the Sixties, the Touring category was one of the areas of motor sport most followed by the public and consequently also by the Manufacturers. Cars derived from standard production models battled it out on the main circuits watched by crowds of fans. And the best drivers were not ashamed to race in this category. Great names included Jim Clark, John Whitmore and Andrea de Adamich. Alfa Romeo wanted to be part of it all and the company decided to commission an workshop to Autodelta, headed by Carlo Chiti, a world-famous designer from the Ferrari stable. The resulting marriage between engineering and motor sport has become the stuff of legend. On February 1965, Autodelta's first creation was presented at the Amsterdam Motor Show and to Geneva car show. The car was a development of the Giulia GT, rechristened the GTA , The letter A stands for alleggerita (lightened) because 205 kg was shaved off the weight of the standard production model through the use of light alloy outer panels fully riveted to the structure (without antinoise panels). The racing version weighed just 700 kg. The interior body was the same as that of the GT, but the exterior trim was made out of Peraluman 25 a Special Aluminum alloy, The side windows and rear window were also replaced with plexi-glass. Furthermore, many components used exotic materials like magnesium in the wheels and other castings, a light alloy of aluminium, manganese, copper and zinc. The new car differed from its sister externally in the addition of front air intakes, handles and the triangular Autodelta badge.
Alfa Romeo Giulia Sprint 1600 GTA stradale
The 1600 Twin Spark twin shaft engine underwent rigorous reinforcement to increase the power output from 106 to 170 bhp. The first ever racing outing of the Giulia GTA was in 1965 at the hill climb race of Trento-Monte Bodone, a race in which the GTA won its class on debut. Giulia 1600 GTA The first GTA to go into production was the Giulia 1600 GTA in 1965. There was the option of two trims available to the prospective buyer. The first being the “Stradale” or road going version of the car, and the second being the “Corsa” or pure race trim. The engine for this GTA was the legendary double overhead cam, aluminium motor which was modified to a twin spark with 8 spark plugs managed with a Marelli distributor as used in the Ferrari and Fiat Dino. This motor featured 45mm carburetors and a magnesium camshaft, sump and timing cover. The close ratio gearbox was equipped with lightened gears for faster shifting. In Stradale trim the GTA produced 85 kW (up from 78kW in the Giulia), while the “Corsa” version was capable of producing up to 130 kW. In order to comply with the Homologation rules introduced into touring car racing, 500 cars were built for racing and road usage.
Giulia Sprint 1600 GTA Autodelta works
The GTA 1300 Junior was launched in 1968, with production continuing up till 1972. The car had a 1300cc straight 4 engine that was based on the 1600 engine, but used a shorter stroke crankshaft. The stradale version produced 81 kW, while the Corsa (Autodelta prepared) fuel injected versions had up to 121 kW. In the stradale form the GTA Junior did not have many of the weight saving features of the 1600 GTA. In total 450 GTA Juniors were made.
Alfa Romeo Giulia 1300 GTA Junior
The GTAm was manufactured between 1970 and1971. Its 2 liter engine was capable of producing up to 180 kW. It is thought that the Am in GTAm, stands for "America" due to the larger engine size that was adopted, derived from the American GT version, in order for the car to race in the 2000 cc classes. The GTAm had a full steel body with modified Glassfibre and aluminium panels. The 1750 GTV was used as the base platform for the GTAm, with its SPICA mechanical fuel injection system. Exactly how many GTAm’s were built is difficult to say due to the fact that some were built by Autodelta and others assembled by private racing teams. The majority of the GTAm’s built by Autodelta have the chassis number starting with 105.51XXXXXX, while the 1750 GTV’s, that were also used as a base had the chassis number starting with 105.44XXXXXX. It is estimated that 40 GTAm’s were produced. Both the 1750 and 2000 GTAm cars were winners of the 24 hours of Francorchamps at the hands of Toine Hezmans. These cars were very successful, winning many races before the competition began to catch up in 1971. Nonetheless the little 2 liter GTAm’s were often able to run with cars with much bigger engines, such as the 3 liter BMW CSL.
Giulia GTAm 1750/2000 Autodelta works
The GTA-SA is the rarest member of the GTA family, with only 10 ever having been produced between 1967 and 1968. It was unveiled to the public at the Third Racing Car Show held in Turin in February 1967. The “SA” in the name makes reference to “Sovralimentato” (supercharged), meaning that the car’s 1.6 liter 4 cylinder engine was capable of producing up to 180kW of power. This allowed the car to reach a top speed of 240 kph. The GTA-SA’s were built for the FIA Group 5 racing series in Europe.
Giulia GTA-SA Supercharged Autodelta
Giulia GTA-SA Supercharged Engine