Hi,
Can someone explain the possible reasons of Fisi's engine stall during his pit in Silverstone.
And some relating questions:
- do f1 engines have idels cicle (not sure that it's right word in english but I hope you understand me) or a pilot has to use brakes and clutch to stand still on a pit?
- if so can the Fisi's accident be a driver mistake (wrong acceleration work after using clutch)?
Heya,
I cant answer all your questions but feel that I might be able to help.
To pull away from the pit-stop the driver pushes a button (launch control), so i doubt its his fault. Martin B spoke about an anti-stall system that was not functioning. To me it would seem that this system monitors the RPM or (and or torque) and releases the clutch if the RPM is reduced below a certain amount.
So we can only speculate as to why the system did not operate properly, so i guess jumping to conclusiong would be silly.
The launch controls on a modern F1 car are fairly sophisticated, I'm sure, and I don't have details of how they function. But most stalls leaving the pits are due to the clutches used.
Stalling, when launching from standstill, with any high RPM race engine using a carbon-carbon (CRC) clutch, is fairly common. Even for an experienced race driver. The reason is that the CRC clutch has virtually no "slip" before it engages. So it acts basically like an "on-off" switch.
With conventional clutch facings, like asbestos or metallics, the clutch facings touch and generate heat, the relative coeff. of friction between them DECREASES, and they slip. This allows the car's driveline to come up to speed without stalling the engine.
CRC clutches (or brakes) work exactly opposite. Carbon has the unique property that when it gets hot, its coeff. of friction actually INCREASES. So when the clutch facings in a CRC clutch touch and momentarily slip, they generate heat, which in turn causes the CRC clutch to grab tighter instead of slipping.
They don't use launch control anymore. The driver uses the clutch behind the steering wheel to launch from a standstill in the pits or on the starting grid.
