Tyres are the only thing that connect your car with the ground. This is why this is the single most important factor to be in control over.
Tyre temperature and pressure are the most important factors to be in control of when adjusting a car for the racetrack. The only way to know if your camber is correct is the measure the temperature distribution over the tyre. This can be done with a temperature probe, this in combination with with a pressure gauge will tell you if your camber is correct if you are in danger of overheating the tyres or not using them hard enough.
The data should then be logged on a tyre sheet to document how pressure and temp are varying with different setup and conditions.
This equipment can be costly to buy for an everyday person and can therefore be rented from me for a small amount of money. Please contact me for prices.