Original Mod by BrianB.
Updated Physics, Extensions and Collider by Team WSC Legends.

During 1961, highly regarded ex-Ferrari and Alfa Romeo engineers Carlo Chiti and Lodovico Chizzola established Delta Auto in Feletto Umberto, Udine. The firm offered engineering services to motor manufacturers and soon picked up a commission from Alfa Romeo who wanted to make an official return to motor racing. The Milan company already had a production-based 1.6-litre GT car in the very early stages of development, but its real priority had been to get the new Giulia range into production. As work on the Giulia approached its conclusion, Alfa Romeo contracted Delta Auto to help create a purpose-built GT racer to replace the old Giulietta SZ (Sprint Zagato).

The new machine would be conceived for Group 3 GT racing which stipulated a production run of 100 vehicles within a twelve month timeframe. At the time, GT racing was at an all-time high with the FIA having switched the World Sportscar Championship to focus on these production-based Group 3 Grand Touring cars as opposed to Prototypes. The Prototypes were still eligible to run a limited number of events, but points scored by these more highly developed cars went towards a separate Coupe des Sports.

Zagato unveiled a prototype of the new Giulia TZ at the Turin Motor Show in October 1962. The TZ moniker stood for Tubolare Zagato which referenced the car’s new tubular spaceframe chassis and Zagato coachwork. On March 5th 1963 Delta Auto was re-branded Autodelta. TZ production began in earnest later that year with the chassis manufactured by SAI in Perugia and the coachwork by Zagato in Milan. Final assembly subsequently took place at the Autodelta works in Udine. The Giulia TZ was homologated on January 14th 1964, by which time the model had already made a victorious debut at the Monza Coppa FISA.

The TZ’s special new tubular spaceframe chassis was fashioned from small bore steel tubing by aviation company SAI Ambrosini in Perugia. This arrangement offered considerable weight-saving and rigidity advantages compared to the regular Giulia’s unitary steel bodyshell. The TZ’s body was effectively an evolution of the Giulietta SZ Coda Tronca that had emerged in 1961. Now even more streamlined and with the tiniest possible frontal area, the TZ looked every inch like a baby Ferrari 250 GTO. To facilitate a super low profile hood, the TZ’s engine was installed at a 15° angle. In addition to its trick chassis, the TZ featured significantly uprated suspension which was now fully independent all round. Up front were double wishbones per side with coil sprung hydraulic shocks. Meanwhile, instead of the standard Giulia’s live rear axle, the TZ incorporated a lower wishbone with the driveshaft acting as the upper link and track control taken care of by the radius rod.

Depending on a car’s specification, a TZ could weigh anything from 640kg to 660kg. Towards the end of production, a small number of Tzs were equipped with fibreglass instead of aluminium bodywork to save even more weight. In 1965 Autodelta began racing the TZ 2 which meant the TZ had limited opportunities in a works capacity.

Although the Zagato-bodied Alfa was disadvantaged by the Division II category of the 1964 World Sportscar Championship allowing cars of up to two-litres, many event organisers still ran a sub category for up to 1.6-litre cars where the TZ excelled.

That year, the Tubolare Zagato took a long list of class wins, all of which were achieved by the quasi-works Scuderia Sant Ambroeus outfit unless otherwise noted. The year kicked off with victory at the Sebring 12 Hours (Jim Kaser / Chuck Stoddard) which was followed up with a class 1-2-3 finish at the Targa Florio (where Roberto Bussinello / Nino Todaro finished third overall). Thereafter the TZ took a class 1-2 at the Nurburgring 1000km (Giampiero Biscaldi / Ernst Furtmayr), a class 1-2 at the Le Mans 24 Hours (Roberto Bussinello / Bruno Deserti), a class 1-2 at the Coppa Citta di Enna for privateer Salvatore Panepinto, a class 1-2-3-4 at the Monza Coppa Inter-Europa (Silvio Moser), class wins at the Bridgehampton 500km (for privateers Harry Theodoracopulos / Bob Grossman) and the Tour de France (Jean Rolland / Gabriel Augias for Ecurie Mediterranee) plus a class 1-2- at the Paris 1000km around Montlhery (Silvio Moser / Karl Foitek for Squadra Foitek).