Tyres
Camber
Tyres are a fundamental component on a race car. Camber controls the position of the tread in relation to the road, i.e. negative camber and the wheels are tilted inwards at the top. We leave the positive camber to the oval racers, in Formula 1 and touring car racing only negative camber values are set. The front wheels need more camber than the rear. When going straight, the grip of the front wheels is not so important, but in curves the car leans and with an optimal camber setting (almost) the entire tyre surface is on the road. The rear wheels would prefer 0 degrees of camber, as this gives them full contact with the road surface when accelerating (straight ahead). But the rear wheels also lean into the curve and thus negative camber is also set at the rear. The camber setting is adjusted via the tyre temperatures, i.e. too high a temperature on the inner side indicates too much negative camber.
Principles:
- more negative camber at the front than at the rear
- Never set positive camber, except in Nascar.
- consider the correlation of tyre temperatures (toe-in, pressure, differentials, etc.)
- the inner temperature should never be more than 10°C higher than the outer temperature
Toe-in
Toe-in is the static angle of the wheels (seen from above) to the car. Negative toe-in means that the wheels are positioned like an arrow in the direction of travel. A slightly negative toe-in on the front axle increases stability when driving straight (positive toe-in is again only suitable for oval tracks and Nascars), but affects braking behaviour. At the rear axle, you should only make small adjustments and here in a positive direction. Toe-in is a hotly debated topic and mainly depends on the driving style. However, a slightly negative toe-in at the front and a minimally positive one at the rear is a good starting setting.
Principles:
- slightly negative toe-in at the front minimally positive at the rear gives relative stability
- negative toe-in gives good straight-line braking
Pressure
The pressure in the tyre increases constantly as the tyre temperature rises. The hotter the track, the lower the pressure should be so that even after a few laps (hot tyre) the tread remains flat and does not bulge in the middle.
Principles (pressure):
- high track temperature low tyre pressure
- low tyre pressure better grip
- higher tyre pressure higher top speed
Important things to know about reading tyre temperatures
You have to drive a few laps evenly to get representative tyre temperatures.
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