CVT Technology in Formula One

Behind the scenes of the most exciting Formula One racing competition, there is no less intense rivalry between engineering teams. They put in great efforts in search of sophisticated know-how solutions to yield a competitive advantage for their drivers. But in search of technical benefits, F1 teams frequently exceed the permissible limits. Formula One is considered by many as a pioneer of racing technical solutions, but in many cases new ideas of F1 engineers often come to nothing because of strict rules regulated by responsible authorities (FIA). The history of F1 is full of instances of banned innovative solutions. In this article we will take a look at the story of the CVT transmission technology in Formula One.

It’s hard to imagine a CVT transmission being used in racing competitions. CVTs are equipped with pulleys and belts instead of gears, which ensure improved fuel efficiency and better speed-up characteristics. This technology differs drastically from manual gearboxes that provide a particular set of gear ratios. It also increases the operating capacity of a racing car by allowing the engine to operate at the RPM rate at which it delivers peak power. But, in standard passenger cars, CVTs are usually considered as a “performance party pooper”. Yet, in the nineties, one of the leading F1 teams developed a unique CVT solution for its car.

Engineers of Williams team perfectly understood that since an engine is permanently revving up and down, it is rarely operating at its full power. For an engine to work at its full potential, it is required to keep its speed at the peak of its power – a task that can be successfully accomplished by a CVT solution. The main issue for integration of such technology in racing cars was the matter of finding a robust enough belt to transmit the 850 hp from an F1 engine. Eventually, the Williams' engineers came up with the reliable hardware for its CVT prototype.

Check out a test drive of the CVT-equipped F1 car

In 1993, Williams installed the new CVT solution on its FW15C. The car already could have been equipped with a powerful semi-automatic transmission, but Williams expected that its innovative CVT solution would bring racing performance capacity of the team to a new level. David Coulthard, who was a test pilot in Williams at that time, drove the CVT-equipped racing car on the racing track in Wales and was very excited about the potential of this innovative solution. Paired to the current Renault V10, this transmission allowed the engine to operate at a constant RPM rate where power output was optimal, and ensured the solid tractive effort.

Compared to other F1 cars, Williams' CVT FW15 car sounded quite differently while driving because of a new approach to the engine operation principle. The engine was electronically linked by sensors to the gearbox, thereby keeping the engine speed within its peak power range. It was rumored that the CVT-equipped test car turned out to be much faster than the standard Williams - which was already the leading F1 Championship contender of that time. Long-time F1 fans can confirm that the leading positions of Williams at that time were unassailable. The CVT endeavor took place during a golden era for Williams; the team had access to the best technologies, employed the best drivers, and it seemed like a real competition was only for 2-nd and 3-rd places.

Subsequently, the FIA introduced a rule stating that from 1994 F1 transmission units must have "a minimum of 2 and a maximum of 7 separate gear ratios, thereby banning the CVT solution. It is interesting to note that this rule was approved in a suspiciously speedy fashion after the 1-st practical test of the CVT-equipped car. Despite the fact that the news about successful testing of the new gearbox reached the public shortly after the test drive, there were only few protests from within the Williams team.

Williams' CVT FW15 in DAF Museum

So the unique CVT-equipped car never even saw a race weekend. The test car is now on display at the DAF museum in Eidenhoven in the Netherlands.

What if CVT had it not been banned by the FIA?

Despite the fact that this CVT solution seemed like a real engineering breakthrough of its time, some experts believe that this technology would cause more harm than good.

The primary basis for such a negative forecast of the CVT future in Formula-1 is the fact that if one F-1 team had at its disposal a technology with potential performance advantages, other teams would have to invest significant financial resources in R&D of a similar shifting unit to remain competitive. So this would lead to so-called “arms race” in the racing world, but at that time not all teams wanted or could afford that. Moreover, it is claimed that the CVT technology adaptation in Formula-1 would also require the redesign of engines used in F-1 cars to cope with technical peculiarities of CVTs, thereby increasing development significantly increasing development costs. It should be also borne in mind that CVT transmissions would also require more expensive maintenance service.

Secondly, if you watch the video footage of the test drive, you will notice that the noise of the car is almost constant. Some F-1 enthusiasts at the time thought it would spoil or destroy the show to the public because one could not relate noise to speed. Moreover, F-1 fans could have been disappointed by the fact that the new technology would completely exclude the pilot from the process of gear shifting. The CVT technology is a perfect example of “machines talking to machines”, where the electronics does all the gear changing work, while the pilot can concentrate on the road. Some people also believe that even if CVTs were allowed in F-1, they would likely be dropped shortly after because of friction losses badly affecting torque delivery. All in all, despite the fact that CVTs didn’t become integrated in F-1, this interesting transmission technology found a wide application in road cars from automakers like Nissan, Subaru, and Honda.

Check out creation of a CVT FW15 PC replica