The original TZ, currently sometimes referenced as TZ1 to differ from later TZ2, was developed in together with Autodelta, a company led by Ex-Ferrari engineer Carlo Chiti. It featured a 1,570 cc twin cam engine and other mechanical components shared with the Alfa Romeo Giulia and carried a 105 series chassis number, but was a purpose builtsports racing car, with a tubular spaceframe chassis, light all-aluminium bodywork, disc brakes and independent suspension. The result was a lightweight coupé of only 650 kilograms (1,430 lb) and top speed of 134 miles per hour (216 km/h). The TZ was built both for street and racing trim, with the latest racing versions producing up to 160 brake horsepower (120 kW). Alfa’s twin-spark cylinder head, as also used in the GTA, contributed to the speed of the TZ; the standard Giulia alloy block with wet steel liners was installed at an angle under the hood of the TZ to improve airflow.
Aiding the TZ in its quest for performance was the treatment of the rear bodywork. Incorporating the research of Dr. Wunibald Kamm, the TZ used a style called “coda tronca” in Italian, meaning “short tail.”, otherwise known as the Kamm tail. The principle is that unless you are willing to incorporate an aircraft-like extended tail (not practical for an automobile), there is surprisingly little, if any, increase in drag and a marked decrease in lift or even some downforce by simply chopping off a portion of the tail. Zagato had previously proved the success of this tail treatment in their “coda tronca” Sprint Zagato sports-racing cars, and it was a natural evolution to adapt this to the Giulia TZ.
The car debuted at the 1963 FISA Monza Cup, where TZs took the first four places in the prototype category. At the beginning of 1964 the TZ was homologated (100 units were needed for homologation) to the Gran Turismo category. After homologation it started to take more class wins in Europe and North-America. Of the first TZ, 112 units were built between 1963 and 1965. Only built as limited amount these TZ models are quite collectibles nowadays