Lotus 72: 55 years of legacy on the track (Part 1)

Written by Lorenzo Baer, Edited by Gabriel Tsui

Jochen Rindt at the 1970 Dutch GP. The race would be a game changer in the history of the Lotus 72. Credit: Jim Culp

The Lotus 72 continues to be one of the synonyms of evolution in motorsport. Groundbreaking with bold concepts, the legendary car from Hethel built a spectacular history on its trail, forever changing the face of Formula 1. 

In the first part of this special, we will delve into the development of the Lotus 72 and some innovations that elevated this car to one of the most revolutionary machines of its time.

The Path to the Lotus 72

Perhaps one of the most emblematic names in motorsport is that of the team created by Colin Chapman in 1954. Founded on simple foundations in a small shack in the suburbs of London, Lotus became one of the great game changers in the history of F1, with a squad led by the genius of characters such as Len Terry, Maurice Philippe and Keith Duckworth. 

It's safe to say that Lotus became a powerhorse due to its desire to push to the limit, transforming what many other teams considered impossible, or even ridiculous, into the truth.

Lotus's first major break with traditional Formula 1 models came with the revolutionary Lotus 25, in 1962. The car, built on a stressed monocoque chassis, as opposed to the spaceframe chassis employed by all Formula cars of the time, became a symbol of an innovation that still has its influence on today’s F1 cars.

Next, it was the turn of the 1966 Lotus 43, which despite not being one of the team's most competitive cars, was important for using a specially designed engine that was also a stress-bearing structural member of the vehicle, a very singular technology in F1 so far. 

The next big step in the team's evolution came with the 1967 Lotus 49, as it became the very first F1 car equipped with a Ford Cosworth engine, a machinery that would establish a dynasty on the tracks in the 1970s and 80s.

In 1968, an evolution of the Lotus 49, the B spec, would become the first F1 car to use aerodynamic mechanisms (wings) mounted directly to wheel hubs. This innovation forever changed F1, promoting a huge breakthrough in aerodynamics..

Despite the success of the 49 model, it was clear to Lotus at the end of 1968 that it was time to evolve again. The failure of the futuristic 1969 Lotus 63 (an experimental F1 4WD car) opened a gap for the development of an even more radical vehicle, which would demonstrate all the genius of the team's designers. Thus begins the story of the Lotus 72.

Breaking up with rules

First public appearance of the Lotus 72, in January 1970. Much of the car's inspiration came from the previous Lotus 56 and 63 models. Credit: Classic Formula 1 via Facebook/Meta

One idea was common to all designers involved in the 1970 Lotus project: the basic cigar-shaped design of F1 cars, which had been evolving since the 1930s, had already reached the limit of its development cycle.

Looking for inspiration, Lotus turned to its own products and ideas. The first was the aforementioned Lotus 63 which, despite having shown little on the tracks, was a car in its own right, and presented a clear evolution in the design of a Formula-type vehicle, with an edge-shaped rear bodywork and integrated wings.

The second major influence on the design of the soon-to-be-born Lotus 72 came from the Lotus 56, another of the team's radical designs. Developed for the 1968 Indianapolis 500, the car was powered by a gas turbine.

Nevertheless, the Lotus 56 most striking feature was its wedge-shaped design, due to absence of a radiator in its nose - which allowed the section to be truly slim and aerodynamic. This novelty would be the first step towards the aerodynamic refinements that were to come in the following years.

With these two models in mind, work began on developing the new car. Headed by Chapman (head of Team Lotus at the time) and Philippe (chief designer of the team), the project was based on an aluminum monocoque chassis, which already presented innovations with its very narrow front section.

From then on, almost everything was an innovation for a F1 vehicle. Firstly, it was decided that the “wedge” format, imported from the 56 and 63 models, would be chosen for the new car, as that would be the most adapted to the demands of the new design. 

Another feature to be carried over from the team's past models was the low profile nose, a clear influence from the 56 model. 

However, although the turbine car seemed to be an interesting basis for the development of other parts of the model 72, a major incompatibility existed between the two vehicles: while the Lotus 56 was thrusted by a turbine, the Lotus 72 would have to be powered by a combustion engine.

The Lotus 56 would serve as a major insight for the type 72. The car's wedge-shaped bodywork would influence almost all F1 cars that would follow. Credit: IndyCar

The clearest consequence of this was that the Lotus 72 would have to have radiators, something that did not exist in the 56 model. Such a feature could have ended the 72 project, if it were not for a brilliant move by Chapman and Phillipe.

Leaning over a drawing table, the duo found a solution by placing the radiators on the sides of the car, in a position flanking the driver. The 'side-pods', as they later became known, improved aerodynamic efficiency, while guaranteeing other great advantages, such as weight reduction, improved vehicle stability and better handling.

The two radiators mounted on the flanks were no higher than the car's waist and were integrated as an essential element in the vehicle's design. Initially, two small snorkels on each side of the roll-bar fed air to the engine, but starting with the 72D model, a tall air box was installed on top of the V8.

This solution allowed the nose of the vehicle to be unobstructed, just as Chapman intended. For him, from the start of the 72 project, a great emphasis was to be put on aerodynamics.

To achieve this, wings were part of the project from the scratch, something that until then no F1 team had attempted to do. Since the beginning of the aerodynamic revolution in late 60s, teams adapted the chassis to receive aero devices – Lotus, on the other hand, went against this tide, creating a car around a cell already prepared to receive such refinements. 

Thus, the nose of the Type 72 was designed with a built-in wing, something that significantly helped with the stability. Complementing the front, another large wing was placed at the rear of the car, guaranteeing an equal generation of downforce, a differentiator in the new car.

One of the few privateer Lotus 72, this 72C was part of Brooke Bond Oxo Racing team in 1971. Credit: GP Library 

In addition to these clearest evolutions, other major innovations helped elevate the Lotus 72 into one of the most promising cars on the 1970 F1 grid: most of the mechanical structure of the car was in-board mounted, such as the brakes and part of the suspension, something that considerably improved the performance of the vehicle on bumpy surfaces. 

The car was also equipped with a brand-new suspension system, as the front suspension was assembled with “anti-dive” geometry, which prevented the car from diving into the ground during braking. Similarly, the rear had an “anti-square” geometry, which prevented the model 72 from sagging while accelerating.

Closing the Lotus 72's package was its ‘heart’: a naturally aspirated 3.0-litre V8 Ford Cosworth DFV, one of the best machinery on the grid. In 1970, this engine generated approximately 440 hp, and by 1975, this value had already risen to 475 hp. Complementing the engineering package, a Hewland FG five-speed gearbox. 

At the beginning of 1970, everything was ready for the debut of the new vehicle. Would Colin Chapman's risky move pay off in the end?