In the previous article, we looked at the prototype Formula One constantly variable transmission (CVT) system that Williams developed in conjunction with Van Doorn in the early 1990s, and spoke to engineer Arnaud Boulanger who was involved with the project.
Anyone who follows Formula One closely will remember the dominant position that Williams had at that time. The CVT’s development happened during a golden era for Williams; having the best car, they attracted the best drivers and for years were considered ‘kingmakers’ owing to the fact that, more often than not, the world champions drove a Williams. Read more…
More than 15 years ago, a young David Coulthard said he was “very excited” about a new development at Williams, going on to say that “machine is working better than man”. The reason for his enthusiasm was that he had just tested Williams’ revolutionary continuously variable transmission (CVT) system. This was in 1993, and the system so worried other competitors and the FIA that it was banned before it could be raced. There is video on the internet of the car being tested in CVT guise, and it is well worth watching - and listening to.
With the adoption of independent, or de Dion rear suspension by racing car constructors during the 1930s, some means of transmitting the torque from the transmission into the wheel hubs had to be devised that accommodated the vertical motion of the wheel.
In the last edition of Monitor we introduced the concept of ‘Tractive Effort’ curves plotted against road speed to analyse performance.
In recent RET-Monitor features we have considered several aspects of transmission design and engineering, each time with the implicit assumption that some means of gearing between the power unit and road wheels was a prerequisite feature.
One of the problems faced by race car designers is the conflicting requirement of keeping a low centre of gravity for the engine (and transmission), whilst keeping the driveshaft within acceptable values. Whatever the chosen method of coupling excessive angularity will lead to increased power losses and ultimately, failure of the joints.
The appearance of the pull type clutch in the race car world in the last decade was driven mainly by considerations of efficiency, consistency, and component life. These factors are improved by an increase in the mechanical advantage of the release mechanism.
The traditional race car multi plate clutch is essentially a friction drive that transmits engine torque into the transmission itself. Layers of plates are alternately geared to the clutch housing, which is bolted to the engine flywheel and also to the clutch hub, which is splined to the gearbox input shaft. When a heavy axial, or clamp load is applied to the assembly, the friction produced between plates prevents any rotation between them and we have a solid drive without any additional mechanical engagement. Transmitting this drive depends on maintaining the clamp load. This is usually obtained by
In previous Monitor features we have touched upon the automated gearshift of a modern race car and attempted to put it into historical context, but how many of its mechanical design features represent new thinking ?
Up until the end of the 1950s, when the front engined Grand Prix car predominated, it was not uncommon to find it’s transmission attached to the engine bell housing, in classic road car configuration, with the box itself almost always in-line, and often road car derived. But it was equally the norm to find the transmission in unit with the rear axle and differential, particularly in a thoroughbred racing design, in which case it was as common for it to be aligned transversally, as in-line.

