Q: “I’m trying to develop better tire management skills for my lapping days with the Porsche club. Currently I have been simply bleeding back the tires when they are hot, to a targeted pressure and using chalking to try and determine if the targeted pressure is high or low. This has worked okay, but not ideal as I still ended up burning off the three middle sections of my rear tires with little wear on the outside sections. I’m looking to doing tire temp readings after each run, checking inside, outside and middle to determine if the tire pressure is correct. My challenge is I’m usually by myself at the track and getting the 12 temps and 4 air pressures after a run, in time to be valuable will be a challenge. Any insights on tools, techniques for tire management in the dry and wet would be greatly appreciated.”
A: You identified the biggest problem with using tire temperatures to fine-tune your pressures: the amount of time that lapses from when you’ve come off the track to when you check them.
This is one of the biggest mistakes I see drivers make at the track when using tire temps. First, the cool-off lap is not working the tries the way they have been while at speed, and then there’s often a long-ish straight from the last corner and into the pit lane. Often, the driver then has to slowly drive back to his/her paddock spot before being able to get out of the car to check temps and pressures. They will not give an accurate picture of what’s going on while on the track at speed by this time.
Ideally, you would drive as hard as you could, come through the last corner and immediately come to a stop and have someone there with a pyrometer or IR gauge. If you can’t do that (and it’s rare that you can, unless you have a private test day), having someone standing in the pit lane (as close to the entry as possible) with a pyrometer or IR gauge is the next best solution.
Now, you could install IR temp sensors on your car, integrated into your data system. That’s not an inexpensive solution, but it’s the best way of using tire temps to tune your tires and handling. Contact your favorite data system retailer for info about that option.
Of course, if you don’t have time to take tire temps and pressures after each session, you might not have time to download the data and analyze the tire temps, either. I’ve seen more than a few drivers spend a fortune on data systems and then not have the time to fully use them the way they should.
Having said all that, you know what the best tire tuning tool is? You. If you pay close attention to what the tires are telling you, you’ll be able to sense whether they’re providing more or less grip – and that’s all that really matters.
Chalking the tires sometimes work when autocrossing, as the runs are short enough that you can run higher pressures. But if you run high enough pressures to where you don’t see wear on the upper part of the sidewall, you’re probably going to end up with pressures that are too high – and excessive wear in the middle of the tread.
I’m not going to get into the details of using tire temps here, but if you have equal readings across the tire, you’re probably not generating maximum grip, and it’s likely that your alignment is not ideal (for sure, you’re not running the ideal amount of negative camber if your temps are equal across the tread; you should see as much as a 20-30 degree spread across from the inside to the outside).
One last comment here: If you’re looking for maximum tire life, you might find that does not match with maximum grip. Often, when your tires are generating maximum grip, you will wear out one part of the tire much faster than another. You know the old saying, right? “How fast do you want to go? How much money do you have?”