In 1970, after several years of underwhelming performances, Ferrari introduced the 312 B model to Formula One. For the first three years, it provided a moderately successful return for the Scuderia, but by 1973 they were being overtaken once again. It was becoming clear that some of the handling issues that plagued the 312 B3 chassis could not be designed out, so it was time for a more significant redesign.
For 1974, Ferrari made big changes. First was signing Niki Lauda away from BRM. The second was the development of the 312 T in preparation for the 1975 Formula One season.
The first variant of the 312 T was designed by Mauro Forghieri. It was a simple, uncomplicated, and elegant design that was very receptive to mechanical upgrades. The new car was built around the flat 12 cylinder engine, which was considered extremely reliable, and produced approximately 510 hp. Perhaps most innovative about the 312 T was it's transverse mounted gearbox – signifying the T in the cars name. This configuration allowed the gearbox to be positioned ahead of the rear axle, giving the car a low polar moment of inertia. The 312 T suspension design was also a significant departure from the previous car. The new design was inherently more neutral, versus the inclination to understeer that belied the 312 B3 model. The chassis was otherwise pretty standard issue for other Formula One cars for the time, with aluminum panels attached to a tubular steel spaceframe.
Although the 312 T was completed at the conclusion of the 1974 season, the team utilized the older 312 B3 chassis in the first two races of the 1975 season. The new 312 T's ultimate debut at the South African Grand Prix was rather unfortunate, with Clay Regazzoni's car being set up poorly, and Niki Lauda's car suffering from low power due to a technical issue with the engine.
After continued testing, they ironed out some of the issues of the new design. Lauda eventually won four out of the next five races, before ultimately winning the season championship in Monza with a podium finish. Regazzoni won the Monza race, securing a constructors championship for Ferrari - their first since 1964. Lauda put an exclamation mark at the end of the season, winning the US Grand Prix, and validating Ferrari's superiority in 1975.
The team started the 1976 season right where they left off, with Lauda winning the first two races, and Regazzoni winning the third. But the technical regulations were being modified for the 1976 season. The high mounted air boxes were being banned after the third race. Ferrari was prepared with a successor – a revised version named the 312 T2. Since the high mounted air box was no longer legal, Ferrari instituted NACA-styled air intakes on either side of the cockpit, which fed air into each cylinder bank of the flat 12 engine. The wheelbase had been extended an additional 42 mm, and a new rear suspension was incorporated, although ultimately they would return to their more conventional design.
The 312 T2 was proving more successful than its predecessor. Lauda won another three races and was leading the world championship comfortably before the now infamous 1976 German Grand Prix at Nürburing, where his accident, suspected to be caused by a rear suspension failure, nearly burned him to death.
Miraculously, he returned to racing only six weeks later. Despite missing several races, Lauda ultimately lost the driver's title by one single point to James Hunt. But the 312 T2's superior performance provided Ferrari with it's second consecutive Constructor's title.
The 312 T2 was utilized without major modification for the 1977 season, but the other teams were working on some big ideas - like Lotus with the ground-breaking 78. As the season progressed, Lauda became increasingly unhappy with the performance of the car, and asked for several changes, including a new rear wing, revised bodywork, and suspension. Once Ferrari executed these changes, Lauda went on to win the 1977 South African race.
Despite the improvements to the car, the Goodyear tires the team was using were becoming increasingly unusable for Ferrari. Goodyear was developing their tires to work in conjunction with the high downforce Lotus 78. That made matters increasingly difficult for the Ferrari. With significantly less downforce, it was very diffuicult to build up sufficient tire temperatures.
Despite these issues, the 312 T2 was sufficient to win the drivers championship for Lauda in 1977 – probably more a result of the car's reliability than it's outright speed. The Constructor's championship was Ferrari's for a third consecutive season. Despite their Championship success, Lauda walked out on the team before the season had fully concluded. He would ultimately be replaced by Gilles Villeneuve.
The neutral handling of the 312 T2 did not at all suit the loose, sliding driving style of Villeneuve. Ferrari knew they were going to have to make some significant changes for 1978.