Spinners

[David Kirkham]

Originally Posted by A-Snake

I interpret the above as follows;
The peak acceleration of 1.5G’s of an F1 would be achieved at a relatively low speed. It’s not going to achieve 1.5G’s when the car reaches 200MPH. Nothing to do with tires here. The maximum acceleration simply tails-off.
If he is braking hard from 200MPH to 40MPH wouldn’t the G’s remain much more constant then when the car was accelerating from 40 to 200MPH?

No, braking g's tail off (non linearly) from 200 to 0.

As the car goes slower and slower the down force applied to the wheels becomes less and less giving the wheels less and less grip and hence less and less ability to decelerate the car.

In addition, the aerodynamic drag forces on the car become less and less the slower you go (remember the above drag equation from NASA). The equation states drag is a square function of speed. At 200 mph the F1 cars are set up to give the wheels all the braking force the brake system can possibly manage (to take advantage of the enhanced grip and to cope with the increased rotational inertia of the wheels, rotors, and drive line components). Hence, you can brake at a MUCH higher negative g at 200 mph than you can at 20 mph because of increased grip and increased aerodynamic drag at 200 mph.

If the driver nails the brakes while going 20 mph in the pits he will simply lock the tires up. That does not mean, however, there is "too much brake" in the system. He needs all the brake possible to slow the wheels and rotors when they are spinning at speeds Ahamenajad would be envious of.

David