Williams-Renault have used the same AP clutch for the past couple of seasons. When operated it activates a potentiometer that determines how close the clutch is to its bite point, then informs the car's electronic system when to deploy the conventional hydraulic actuation system. But while Jacques Villeneuve prefers the hand-operated version, Hill doesn't, and is more comfortable with the more conventional foot- operated variation.
"AP is continuously making small modifications and improvements to the clutch, sometimes to help it stay alive. It rotates up to 16,000 and something rpm, so it's quite a critical item," explained Patrick Head, Williams' technical director, who provided some interesting insights into Hill's apparent tardiness.
"If you can imagine having a hand clutch and only two pedals, you have the possibility of putting your right foot on the throttle and the left hard on the brake while simultaneously letting the clutch out until you feel the car straining against the brakes as the clutch bites, and then taking your foot off the brakes when the lights change. You have found the bite point, the point at which the clutch starts gripping. You have found that in advance of the start, so all you have got to do is take your foot straight off the brake pedal and boompf! You're going.
"The thing you've obviously got to be careful of is that you don't pump too much heat into the clutch while you're doing that, and overheat it. Slipping clutches these days are not really a problem because the actual material of the plates is carbon, which is capable of taking enormous temperatures. The problem is the housings which hold the plates, which tend to be aluminium, and the diaphragm spring which is steel, so what tends to happen is that you destroy not the plates but the rest of the clutch. The steel diaphragm gets so hot that it tempers down and loses its spring strength, that sort of thing. It's a question of not getting the clutch too hot.
"The problem for Damon is that he's got three pedals and only two feet. And if he's got one foot on the accelerator and one foot on the clutch, he hasn't got one for the brake. And though we can provide him with an electronic handbrake [similar to the system that stranded both Benettons on the grid in Germany earlier this season when the handbrakes stuck on] the problem is that you don't have so much feel. You can't feel through the brake pedal when the car is beginning to creep as the clutch bites.
"In the existing situation Damon has to keep one foot on the accelerator, and one on the clutch. He's off the brake pedal, he's got nothing stopping the car moving, so he can't come back and find the bite point on the clutch. So when the lights change he's got to take his foot back on the clutch and find just the right point at which it is gripping to produce drive, but not get so much grip at low speed that it bogs the engine down. He's got to find that point, whereas Jacques has already found that point before the off."
Starting used to be Hill's strong suit, and this last week in Barcelona he has been practising starts assiduously, though whether he too will finally opt for the hand clutch remains to be seen. "It is a possibility," Head allowed. For Hill, the championship may depend upon it.Reuse content