Become Your Own Tyre Technician
Have your been maximising the potential of your powerful built-in data acquisition sensors?
We certainly are able to learn so much from our tyres. Our tyres are a critical component in the race car chassis set up. In fact, it all starts from our tyres, so why not make the very most of the amazing data our tyres are screaming to us the moment we pull up in pit lane.
You don't need powerful software or laptops, just a good tyre pressure gauge and pyrometer (infrared temperature gauge). Decent quality units are available online for less than $50 each, so they're very affordable and essential tools.
The critical aspect of reading tyre temperatures is that they must be done immediately at the completion of some race pace laps. This is pit lane stuff, the very moment the car pulls up. It's no good waiting for the car to get back to the carport. By that time, the tyre surface will have cooled and valuable data lost. Your pit crew must be waiting ready to converge on the car armed with the pyrometer and clipboard.
It's best to always start with the working tyre. The working tyre is the tyre that is taking the majority of the load and is usually the outside tyres and mostly outside front. At Wakefield Park, the working tyre will be the front passenger side (L/H) as this is a clockwise track. At Sydney Motorsport Park, the working tyre will be the front driver side (R/H) as this is an anti-clockwise track.
Measuring tyre temperatures involves taking readings at three points across the tread face. These are the outer edge, middle and inner edge. Inner and outer temperatures should be taken at a point approximately 25-30mm from the sidewall. Pyrometers usually feature a laser pointer to guide the position of measurement and it is best to point into the valleys of the tread pattern in order to avoid inaccurate readings from dust & debris on the tyre surface. Be consistent with this measurement point with each and every measurement session.
- Middle higher than inner and outside edge. Tyres are over-inflated. Bleed back tyre pressures.
- Inner & outer higher than middle. Tyres are under-inflated. Inflate tyres.
- Inner edge hot with middle and outer edges progressively cooler. High negative camber. Negative camber may need to be reduced. However, inner edges slightly higher overall is considered OK and is desirable to ensure maximum camber thrust and tyre bite.
- Outer edge hot with middle and inner edge progressively cooler. Not enough negative camber. In this situation, you are throwing away cornering force and traction. The optimum level of camber is critical for cornering force. As a rule, negative camber equals cornering force (lateral grip). You must work on optimising your camber levels with these settings possibly varying from track to track. If your MX-5 is competing in standard class, then the range of camber available is limited and your best option is to increase tyre pressures slightly to achieve a more gradual temperature profile.
- Overall high tyre temperatures possibly on one tyre or a front and rear set. This could be the result of spring rates being too high or a corner weighting problem.
These outcomes are only just the beginning. It cannot be stressed enough how important your tyre pressures and temperatures are when attempting to finely tune your race car chassis for the ultimate set up and tyre traction. At the end of the day it will be "traction, traction, traction" that will win the day, and this is all about maximising the contact area of those four tyres.