I agree with with......... a lot of what Al said. CHT is a useful mertic. Most I'll bet do not use EGT and are missing a real gem.
I can tell you for a fact tire temps work. I have used them effectively at 34 degrees of outside temp.
I have used a stack data logger with IR sensors and what a tale they tell.
The tires are the connection between the track and the kart itself. It has a tale to tell, you just have to know how to read the story.
Why not use an IR? Lets say a kart is loose, using an IR device would show the kart is tight (pushing) because the surface of the tire is really hot because it is sliding. That makes the surface of the tire really hot but deep in the tread of tire it is cool. The tire seems really hot but you have no AP gain. The tire is not gripping. If the tire were gripping, it would be hot deep in the core and therefore you would have AP gain, where as if it were sliding it would have no AP gain, be cool in the core, but hot on the surface.
Hell, even your shoe soles tell a story and guess what? They even generate heat when you walk.
Most people have no clue as to why you run so much cross on dirt but very little on pavement., where on pavement it is more balanced and even on syrup indoor tracks.
The reason is on dirt the grip between the LR and RR is imbalanced.
On dirt, I always measure the moisture content of the racing groove between the RR and LR. More weight equals more grip in a tire. Therefore, if the track has less grip you have to balance not only rears but also the grip the RF can handle compared the drive the LR is giving. Tire temps will tell that story.
If your driver comes off the track and the kart sits for a while the heat disipates in the tire and is useless.
No matter what data you collect and use you must repeat the results meaning no matter what you are measuring just do it at the same time or you end up playing with yourself!
Mike McCarty
Chassis Manual (Only $17.95)
www.kartcalc.com