Video: Alfa Romeo GTA/ GTAm Track Day
Alfa was very active in motorsport. Autodelta, the racing division of Alfa, developed a car for competition resembled to the roadgoing model. These cars were named GTA instead of GT, the ‘A’ standing for “Alleggerita”, Italian for lightweight. The GTA was produced first in 1965 as a 1600 (1570 cc) and later as a 1300 Junior version. The GTA automobiles were also manufactured in either street (Stradale) or pure race (Corsa) trim.
The GTA had aluminium outer body panels instead of steel, (the inner steel panels were also of thinner gauge, the inner and outer panels were bonded and pop-riveted together), magnesium alloy wheels, clear plastic side windows, an aluminium rear upper control arm, different door handles and quarter window mechanisms, and lightweight interior trim.
The engine had a new double ignition cylinder head (called twin plug, later in the eighties the system was called twin spark) cylinder head with a Marelli distributor from a Ferrari Dino, 45 mm carburetors instead of 40 mm and magnesium camshaft cover, sump, timing cover and bell housing.
The transmission gear ratios were closer than standard and the gears were machined for lightness and quicker shifting. Dry weight of the 1600 was approximately 1,640 pounds (740 kg). In stradale form this car boasted approximately 115 PS (85 kW; 113 hp) (up from 106 PS (78 kW; 105 hp)). In full race form this engine could produce up to 170 PS (130 kW; 170 hp). The 1600 GTA did not have a brake booster and had a thicker radiator than the standard vehicle. For homologation 500 cars were made for racing and road use.
The GTAm (1969–1971) could produce up to 240 PS (180 kW; 240 hp) in the 2000 cc car—a car usually related to the GTA, but unlike the GTA derived from the GTV 1750 (US version). The 1750 GTAm (later called 2000 GTAm when the 2000 GTV was introduced) was created in 1969
The car had a full steel body modified with aluminium and / or plastic parts. Because of an increased minimum weight in 1971 (up from 920 to 940 kg), the GTAm’s had less need for aluminium and / or plastic parts. The base for the GTAm was the 1750 GTV with a SPICA mechanical fuel injection system.
The majority of the genuine GTAm’s built by Autodelta have a chassis number starting with 105.51.XXXXXX. The European market 1750 GTV with dual carburettors from Dell’Orto or Weber carburetor and chassisnumbers starting with 105.44.XXXXXX was also used as a base