Koen Suyk / Anefo, Nationaal Archief, via Wikimedia Commons, CC BY-SA 3.0 NL. (credit links at the end of the content)
We continue our journey through the unraced cars of the past, having already shared many projects that failed to reach the F1 grid for various reasons. Next, we explore the story of the Brabham BT46C, a car that appeared in practice once and never again. But why did it never race?
It was one of the most unusual experimental cars developed during the 1978 F1 season, the car was designed by Gordon Murray, and it appeared briefly during practice before disappearing from the racing scene without ever making a Grand Prix start.
Unlike the famous Brabham BT46B, known as the Fan Car, the BT46 wasn’t built to challenge the competition with a revolutionary aerodynamic concept. Instead, it was a temporary solution to a serious technical problem that threatened to derail Brabham’s plans for the season.
The Brabham BT46 and Its Radical Design
The original Brabham BT46 was designed for the 1978 season, under the leadership of team owner Bernie Ecclestone, with Niki Lauda and John Watson driving for the team.
The car was powered by Alfa Romeo’s 3.0-litre flat-12 engine, which produced approximately 520 horsepower; its wide engine presented several challenges for the designers, particularly as F1 was entering a new era of aerodynamic development.
Murray attempted to solve these problems with an unconventional cooling system, they didn’t use traditional radiators, the BT46 featured flat-panel heat exchangers mounted along the bodywork.
The concept was intended to reduce aerodynamic drag and improve the car’s overall efficiency, but the system didn’t work as expected.
During early testing, the heat exchangers struggled to keep the engine at a suitable operating temperature, and the cooling problem became serious enough that Brabham needed to alternative before the car could be used reliably in competition.
The BT46C: A Temporary Solution
The BT46C was developed as a response to the cooling difficulties experienced by the original BT46, rather than completely redesigning the car, Murray experimented with a more conventional cooling arrangement, the test car was fitted with two Volkswagen Golf radiators mounted at the front of the chassis.
This unusual setup allowed the team to investigate whether conventional radiators could solve the overheating problem while providing useful information for a more refined design.
The result was a car that looked noticeable different from the standard BT46; the additional radiators were mounted on the nose; creating a temporary arrangement that was more practical than the original flat-panel system but far more the clean design Brabham ultimately wanted.
The BT46C wasn’t intended to become a permanent racing car; its main purpose was to help the team find a workable solution to the cooling problem.
Why the Brabham BT46C Never Raced
The BT46C never started a Formula 1 Grand Prix because its temporary radiator arrangement was quickly replaced by a more suitable design, once Brabham accepted that conventional radiators were necessary, Gordon Murray developed a cleaner front-mounted cooling layout for the standard BT46.
The revised car appeared during the early part of the 1978 season and provided a more practical solution to the problem.
The bulky Volkswagen Golf radiator arrangement was no longer needed, and the team could focus on improving the car’s performance.
The BT46C had fulfilled its purpose as a test car; there was little reason to continue developing it as a separate racing model.
The Shadow of the Brabham Fan Car
The Brabham BT46C was also overshadowed by another experimental project that became one of the most famous cars in F1 history.
The Brabham BT46B, commonly known as the Fan Car; featured a large rear-mounted fan that generated additional downforce by extracting air from beneath the car.
The design was controversial, but it proved effective, Lauda drove the BT46B to victory at the 1978 Swedish GP, giving Brabham one of the most memorable wins of the season.
The car was withdrawn voluntarily following intense opposition from rival teams and pressure surrounding its design.
Although the BT46C and BT46B were both connected to Brabham’s experimentation during 1978, they served different purposes, the C-variant was a temporary cooling system test car, while the B variant was a radical aerodynamic development that actually raced.
Related to Brabham: Explore Brabham’s championship-winning cars that brought the team F1 glory.
A Forgotten Experiment in Brabham’s History
The Brabham BT46C never achieved the fame of the fan car, nor didn’t enjoy the success of the standard BT46.
The team reportedly used the BT46C in practice sessions at Hockenheim and during the 1978 Austrian Grand Prix, but the car never made a race appearance.
For Gordon Murray and Brabham, the BT46C was a short-lived step toward solving a technical problem, once a better cooling arrangement was developed, the car was no longer necessary.
It remains a forgotten chapter in the story of the 1978 Brabham team, showing how even an unusual F1 car could disappear almost as quickly as it arrived.
Related to Brabham: Discover the Brabham BT49C, the championship-winning car that used a controversial hydropneumatic suspension system in F1.
Featured Image Credits: Koen Suyk / Anefo, Nationaal Archief, via Wikimedia Commons, CC BY-SA 3.0 NL.
