Tuesday, 11 October 2011

Understanding F1 car - V1: Transmission - Clutch

F1 cars did used to run on the same basis as normal road cars in that they had an accelerator, brake and clutch pedals and H-pattern gear boxes. In the 90's this changed to the same pedal configuration but with sequential gearboxes, in other words you just push the gear control in the same direction and it changes up or down in sequence.
In the late 90's/early 00's this changed to sequential gearboxes and FULL automatic gearboxes for one season, with a hand controlled clutch that was basically a button with a spring underneath it.
Finally you now have a sequential gearbox but with a computer-controlled clutch. The cars even have an anti-stall procedure where if (for example) the driver spins the car, the ECU will automatically knock the clutch out so the car doesn't stall. This is why drivers spin all over the place now and keep the engine alive. Sebastien Vettel complained about this in Sepang because his car spun in the rain and his anti-stall did not operate as it should, he thus stalled. His complaint was that if he actually had a clutch he could operate himself he wouldn't have stalled!
Semi-automatic sequential gearboxes have regulations stating a 4–7 forward gears and 1 reverse gear, using rear wheel drive. The gearbox is constructed of carbon titanium, as heat dissipation is a critical issue, and is bolted onto the back of the engine. Full automatic gearboxes, and systems such as launch control and traction control, are now illegal, to keep driver skill important in controlling the car.
The driver initiates gear changes using paddles mounted on the back of the steering wheel and electro-hydraulics perform the actual change as well as throttle control. Clutch control is also performed electro-hydraulically, except to and from a standstill, when the driver operates the clutch using a lever mounted on the back of the steering wheel. A modern F1 clutch is a multi-plate carbon design with a diameter of less than 100 mm, weighing less than 1 kg and handling around 720 hp. As of the 2009 race season, all teams are using seamless shift transmissions, which allow almost instantaneous changing of gears with minimum loss of drive. Shift times for Formula One cars are in the region of 0.05 seconds. In order to keep costs low in Formula One, gearboxes must last four consecutive events, although gear ratios can be changed for each race. Changing a gearbox before the allowed time will cause a penalty of five places drop on the starting grid.

So practically, the clutch(means 2 pedals one at right and other at left(both doing the same thing - act as clutch) in the back of the steering wheel under the changing gear pedals) is used only for moving off from standstill, as follows: you got to pre-set one clutch position(generally right pedal) half way to full, and the other clutch to full position(left pedal in this example) and when you want to start release as faster as you can the full clutch pedal(left pedal), and when you get some traction you release the other clutch pedal(right pedal).

The engine is linked directly to the clutch, fixed between the engine and gearbox. AP racing and Sachs produce Carbon F1 clutches which must be able to tolerate temperatures as high as 500 degrees. As i say, the clutch is electro-hydraulically operated and can weigh as little as 1.5 kg. The drivers do not manually use the clutch apart from moving off from standstill, and when changing up the gears, they simply press a lever behind the wheel to move to the next ratio. The on-board computer automatically cuts the engine, depresses the clutch and switches ratios in the blink of an eye, just about seamlessly and are only 100 mm in diameter.
F1 clutch test
high temp is 1400Cfriction response at very high energies
more on youtube video description

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