Banned! Continuously Variable Transmission (CVT)

Alain Prost, Damon Hill, Williams-Renault, 2007Williams unleashed one of the greatest technological blows the sport has ever seen in 1992 when their computer-controlled active suspension FW14B stormed the championship.

The technological onslaught continued in 1993 as traction control and anti-lock braking became commonplace and Williams’ rivals up and down the pit lane grappled with active suspension.

Astonishingly even as the FIA sought to ban the expensive innovations, several teams concocted radical new technologies even though they knew they would be illegal in 1994. Benetton’s four-wheel steer (discussed in an earlier ‘Banned!’) was one.

Another was Williams’ Continuously Variable Transmission – which could have revolutionised the way F1 cars sound, had it not been banned.

Great engineering innovations often start with an inspired logical observation. Here’s one:

If a car’s engine is constantly decelerating and accelerating, it is not operating at maximum efficiency. To do that it should rev constantly at the optimum point of power and torque.

This point was well understood by car engineers outside of Williams long before 1993. One solution was to do away with a conventional gearbox and instead use a system of pulleys to adapt the engine’s power in line with what the driver required.

The system – continuously (or “continually”) variable transmission – existed in various different forms. DAF had produced a road car in 1958 called the 600 (or “A-Type”) which featured a “Variomatic” gearbox – which was essentially a CVT.

The problem for using such technology in racing cars was the difficulty of finding a strong enough belt to transit the power from an F1 engine.

In 1993 Williams cracked it and David Coulthard tested the car on a wet July day at Pembrey in Wales. It was later driven by touring car racer Alain Menu (his Renault 19 race car was prepared by Williams at the time).

At first it was feared that a ban on electronically controlled gearboxes would do away with the CVT before it could race. But in the end the FIA came up with something much more direct to get rid of it.

They stipulated that, from 1994, F1 cars had to have between four and seven fixed gears – and for good measure added a sub-clause specifically banning CVT.

Williams’ CVT car sounded revolutionarily different to contemporary (and modern) F1 cars because of the different way it used the engine. Instead of the revs rising and falling with each corner they remaining constant through each bend – a wholly unusual sound for spectators.

There was also speculation that it had instantly proved several seconds per lap quicker than the conventional Williams – which was already streets ahead of its rivals.

Although the technology and offshoots of it have been used in road cars it remained too exotic for the increasingly stringent demands of Formula One. A lone, unraced Williams-Renault CVT sits in a DAF museum somewhere.

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17 comments on Banned! Continuously Variable Transmission (CVT)

  1. Number 38 said on 3rd May 2007, 15:50

    I’ve got some experience with the ECVT transmission and readers might like to know the drive through the “belt” is NOT a pull but a push. The “belt” is made up of 1000s of hardened and ground links and wrapped with many bands of very flexible steel. The bands hold the links in place lest centrifugal force throw them outwards. The drive from the primary pulley PUSHES one link against another towards the secondary pulley. BOTH pulleys are variable width and the width positioning (i.e. RATIO) is controlled by hydraulic pressure,
    the pressure is control by a valve body much like that of an ordinary automatic gearbox and the valve body is controlled by electric information from several sensors; i.e. engine speed, road speed, throttle postion, manifold vacuum, wheel slip sensors, pulley position sensors, and on and on. Even temperature and fluid viscosity can play a part. Engine braking is ackomplished by over-ride features which keep the pulleys at specific positions rather than changing ratio dramatically. If F1 was truly the “Pinnacle of Motorsport” every F1 car would use this advanced technology, to consider the ECVT gearbox a ‘driver aid’ is ludicrious, one has to learn how to use it!!! More on this subject if there’s interest……..#38

  2. I was waiting for a techie to pick me up on something!

    I wonder though if the real reason CVT (ECVT?) has never been re-legalised is because it would make the cars sound so different?

    People can be very hostile about that sort of thing – there’s been a lot of grizzling about the quiet-sounding Audi and Peugeot diesel Le Mans racers.

  3. Perhaps that goes to show where the real development is; my thought on CVTs in racing is that I would expect the belts to be unable to last under the stress, to which I say, more power to you if you want to dare to use it.

    The beauty of a certain Shell advert is hearing the Ferrari’s engine change in note from the 60′s to the present day; I think certain folks will just have to get used to the different sound.

  4. Journeyer said on 4th May 2007, 2:04

    It depends on how you see it, really. I want to see F1 as the pinnacle of motorsport. I want to see the best drivers duke it out, not necessarily the best technology.

    I don’t like ECVT not because it might be a driver aid, but because of the sound issue. I would say I like the noisy engines as they are now. ECVT would be good for road cars, but maybe not for F1. Many people say that the cars look so alike already; would we want them to sound alike too?

  5. Number 38 said on 4th May 2007, 16:27

    Now there’s THREE responses I can’t explain …… pinnacle of motorsport (that’s just a slogan) and everyone is concerned about the SOUND !!!!!!
    I will tell you one thing, if SOUND is your concern you will be DISAPPOINTED in the ECVT as the 18K and 19K revs will never happen…….typically the ECVT is going to operate at peak engine TORQUE which is clearly lower that the scream we’re so accustomed to. SOUND ??????
    Are you folks serious or are you just ‘playing with me?’

  6. Journeyer said on 4th May 2007, 22:36

    Sure, sound. A lot more people actually like that than one would think at first.

    Then you’d realize: why do people love hearing the sound of a Ferrari V12? Why do people talk about how they heard the sound of a Cosworth DFV live? Sure, it’s not the most important part, not by a long shot, but the sound is part of the mystique of the sport.

    If ECVT ever came into the picture, spectators would eventually get used to it. But odds are you’d catch them reminiscing about the roar of those V10s and V8s into the distance.

  7. It’s a European thing, Number 38. Heck, we never even took to auto transmissions – we like being involved with the engine. Hence the call for the return to manual gearchanges in F1. Make ‘em interact with the machine, that’s our view. ;)

  8. Number 38 said on 5th May 2007, 6:47

    Okay lads, I loose this round…..so you think SOUND is part of F1. I’m shaking my head in disbelief. Journeyer “likes reminiscing about the roar of those V10s and V8s into the distance.” I drive a BUICK V-8 everyday, I guess I just don’t appreciate it quite enough. Kidding aside, and to support your thoughts if only slightly,
    I have been treated to the SOUND of a 1950 B.R.M. V-16, that is a sound you don’t forget, the SOUND of the 1960s STP Turbine (Indy car),
    and even the SOUND of my A.J.S. cycle which has but one cylinder! Now there’s a SOUND you pray never stops; at 7000 revs in top gear, if you loose the spark, the compression will slow you so fast that being tossed over the handle bars is a real possiblity! Be quick with the clutch! And all of this started with a discussion about the ECVT transmission. CHEERS!

  9. And there’s nothing quite like the thunder of a big American V8, Number 38 – gets ya right in the gut! But a BRM V16, now there is something I wish I’d heard.

  10. Andres Beltran said on 10th September 2008, 9:05

    Bueno es cuestión de tecnologías y no de cómo se escucha bonito.
    La formula uno es eso y no se pueden estancar en boberías, en este momento necesitamos desarrollar la tecnología mas eficiente, en CVT tenemos una carrera por la mas eficiente y NO se puede quedar fuera la F1.
    Actualmente la CVT es cara delicada débil inestable complicada y lo peor de todo para POCO PESO.
    DE ANTEMANO AGRADESCO LA ATENCION:
    Para mi es un gran gusto poder escribir la presente, esperando que en un momento de tranquilidad puedan leer estas líneas y cuantificar el contenido, y de esa manera darme un poco de su Atención que para mi es de ALTA IMPORTANCIA.
    Por esta y otras muchas razones me dirijo con respeto.
    Quiero DESARROLLAR MI INNOVACION Ustedes son La Clave, por los conocimientos y contactos que tiene.
    Uno de mis proyectos es interesante por el resultado de sus funciones.
    TRANSMISION CVT (PARA TODO VEHICULO TODO PESO)
    Ahorros Aproximados:
    a- 25% En todo tipo de Combustibles.
    b- 40% En todo tipo de Motores., (controlado régimen de RPM)
    c- 30% Emisión de Contaminantes.
    d- 35% Tiempo aceleración (Velocidad de Crucero)
    e- 30% Caída de velocidad en Pendientes.
    f- 70% Crucetas (No hay jaloneo)
    Es difícil creer en alguien o en algo, hasta que se puede comprender, y para esto tengo que demostrar el funcionamiento del EQUIPO EN CUESTION.
    Muy bajo CAPITAL:
    1- PROTOTIPO: Para demostrar su funcionamiento y enumerar cada una de sus cualidades, como primer paso y estar seguros antes de patentar.
    2- PATENTAR: De esta manera ya convencidos del buen funcionamiento del EQUIPO y con Gusto se conformaría la SOCIEDAD, y seguir con los gastos de Patentes.
    MI CVT ES (TODO VEHICULO Y TODO PESO) bici coche tráiler locomotora etc..
    ATTE: Andrés Beltrán T. jabt57@yahoo.com.mx jabt57_@hotmail.com

  11. oogabooga said on 28th March 2009, 6:01

    Sound? Pfft, whatever. The fun thing about this is that anyone who thinks the cars will just zoom around to a constant sound is completely wrong. Not only do engines change tone and volume immensely as loads are put on them, but as someone already correctly pointed out, around corners, torque is very important. So drivers would drop the revs there, but there would still be the usual increase in pitch along straights as power starts to become far more important.

    I just looked up what this new KERS is, and to my astonishment, the mechanical version appears to be a horribly complicated add-on that is basically a flywheel and a CVT. It should have simply replaced most of the geartrain. The whole system seems unnecessarily complicated and completely backwards now (the electronic version is unrelated and still makes sense).

    Amusingly, I 1st heard of CVT when I was a kid reading my grandfathers old amateur auto magazines from the 1930s. I’m still infatuated with the idea. Back then the strength and endurance of the the system was a prohibiting problem, but if they developed working versions in 1993, I see no reason why it’s not in my everyday road car yet – it’s more efficient, it’s a smoother ride, it’s easier on the engine, it’s easier on the rest of the drive train… the list goes on.

    The only reason I can think of is that infinite gear type gearboxes just keep getting banned in racing. As we all know, almost nothing gets mass produced without 1st being tried in racing. This one in particular, is a horrifying shame in my opinion.

  12. Andres Beltran said on 9th April 2009, 18:13

    México D.F. Abr. 2009
    TRANSMISION CVT Flexible (Todo Vehículo Sin Límites de Peso)
    INNOVACION, se Vende o Renta, escucho Propuestas)
    CUALIDADES y AHORROS aproximados:
    a- Fabricación sencilla en Aceros Convencionales
    b- Vehículos (Bici – Motos – Autos – Camiones – Locomotoras Etc…)
    c- Motores (Eléctricos Gasolina Diesel Etc…)
    d- Motor mas pequeño (Mismo Rendimiento)
    e- 35% Combustibles
    f- 40% Motor
    g- 40% Contaminación
    Andrés Beltrán – jabt57_@hotmail.comjabt57@yahoo.com.mx
    Buena Oportunidad para Recibir apoyo como Innovador, Gracias.

  13. Muy informativo. Saludos

  14. ANDRES BELTRAN said on 4th September 2011, 5:38

    HOLA COMUNIDAD:
    El hecho de contar con una página para exponer nuestras ideas ya es un avance, Toda Mi Gratitud.
    Y si ustedes lo permiten, ayudemos a la humanidad, en el medio ambiente y otros.
    Tengo un importante invento Innovación:
    Transmisión CVT. Con Las Siguientes Cualidades:
    Contamina 35 a 40% menos.
    Ahorro de combustibles 35 a 40%.
    Fabricación más barata con Aceros Convencionales.
    Vehículos de Todo Tamaño. Todo Peso. Todo Motor.
    Beneficios Ecológicos y Económicos.
    Tengo el apoyo de La UNAM, IPN, ICyT D.F. en gastos de patentes.
    EL CLUB de INVENTORES de ESPAÑA.
    Pido apoyo económico en sociedad, para construir Prototipo, para recibir ayuda con los gastos de Patentes.
    ATTE: Andrés Beltrán.
    Mail jabt57@yahoo.com.mx

  15. Andres Beltran said on 4th December 2011, 8:22

    HOLA , (Alemania y Japón) soñar es la parte Grandiosa del Ser Humano, las Posibilidades de que este Comunicado llegue al Conocimiento de las Personas Indicadas, Son bajas, La Certeza en el Proyecto y Mi Espíritu, me Impulsan.
    Mi Gratitud Infinita, a las Personas de Gran Mente y Capacidad:
    SOLICITUD, Ayuda, Económica en Sociedad, Es una inversión pequeña para Armar el Prototipo, el cual Puedo Construir y Ponerlo a Trabajar en Muy Poco Tiempo.
    El Resultado, es el Requisito que me Piden las Instituciones, (IPN, UNAM, ICyTDF), Ofrecen Pagar los Gastos de Patentes y Trámites Legales.
    Las Ganancias Podrían ser Altísimas y con la posibilidad de Patentar y Fabricar en México, y crear Trabajo y Riqueza.
    Otra Opción Relevante, es Rentar las Patentes a las Grandes Empresas armadoras de Trasmisiones, como (JATCO en Aguascalientes, TREMEC en Querétaro) (Alemania y Japón) Etc.
    PROYECTO:
    Alta Tecnología 100% Mecánica, Con Bajo costo de Fabricación.
    Transmisión CVT – TODO (Vehículo, Peso, Motor, Torque y Energías).
    Propósito, Bajar Costo de Fabricación y Subir Utilidad.
    BENEFICIOS Para la Humanidad Muy altos, Ecológicos, Económicos, Alto Desempeño y Rendimiento en toda clase de Energías.
    Las actuales Transmisiones CVT, costosas y delicadas, si se descompone, casi es preferible comprar otro vehículo.
    Es la Gran Oportunidad de juntar nuestros Esfuerzos, Formar una Sociedad.
    Podemos Lograr que Funcione.
    México D.F.
    ATTE: Andrés Beltrán.
    Mail jabt57@yahoo.com.mx
    Celular (México 52) 044 55 3888 5195

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