# What a dragster!

1. Nov 22, 2003

### Loren Booda

Why are a dragster's tires allowed to slip, rather than obey positraction? Is it that friction of rubber is idealy a nonlinear function in this particular range of temperature, or that the Clorox applied needs to be evenly distributed and incorporated for coherence? (Maybe to avoid starting out with a wheelie?)

2. Nov 22, 2003

### krab

In order to get really sticky, the tires need to reach a certain temperature.

3. Nov 23, 2003

In a race, the idea is for them NOT to slip. If you start wheelspinning, you've lost!
As Krab says, the burn out at the start is to get the tyres to their (very hot) operating temperature.

Incidentally, the 6000bhp 'top fuel' cars do the 1/4 mile in around 4.5 seconds with a terminal speed of over 320 mph! Awesome!

4. Nov 24, 2003

### Stingray

The big wheelspin before staging is to warm up the tires. There is still a little bit of slip during the race though. Smoky burnouts don't give any traction, but all tires must slip a little to generate forces. The simple type of friction taught in most physics classes doesn't apply to rubber at all.

5. Nov 25, 2003

### Mr. Robin Parsons

As a scientific person I am rather certain you will understand that 'Bleaching' is actually a process, not a substance, (in this use of the term) as the stuff they put on the tire, for the warming up the tires, by 'burnout', is water.

As for the 'slip' of the tires, the positraction simply ensures the energy transfer to the tire with the most traction, but can do nothing to stop either of the tires from slipping, as it has no 'control effect' upon the amount of torque being exerted.