Charley Hoyt

I always hear people refer to making sure tire temperatures are taken correctly....please share the correct methods. This is what I have learned so far:
1) use a quality probe sensor.
2) take the temperatures as soon as you come off trach after a hot lap
3) take three readings per tire starting on the inside of the tire that is under the greatest load and then moving to the center, then the outside...making sure not to get too close to the edges and not in any rubber picked up off of the track.
4) keep a log of the tire temps including the ambient temperature and the track .

What else is recommended?

Thanks for the help,
Charley

LateBreak

That pretty well covers it, Longacre sells a nice probe Pyrometer with 10 Memory spaces, makes it very quick to measure and log all your temps without having to write them down as you read them. If you do have to write them down to record them, I like to put a piece of tape on the fender above each wheel where the temps can be written down quickly after each sesson, then when you have more time you can either put the tape right into a book or transfer those numbers into a logbook.

rfn026

Make sure the probe goes below the surface of the tire. You really don't care about the surface of the tire. You want to know what the temp is of the rubber below the surface. Then wait a second of so for the temperature to stabilize. I usually insert the probe at and an angle. Here's an article I wrote about tire tools a couple of years back.

Richard Newton

Bill32

The Longacre probe is adjustable so you are always measuring the same depth.

The Longacre gauge will tell you when the reading stabilizes by jumping to the next reading. The first reading is on the RF outside but that doesn't matter that much if you only have a single reading meter.

Longacre has sheets to record the data, I made my own,

I measure the track temp with an IR gun.

When taking into account the camber affect on the inside readings, you can average (add the inside to the outside and divide by 2).

Keep in mind that where you get your air from may affect the temp rise, air from your frequently drained compressor may have less moisture content than air from the track's compressor. A nitrogen setup pretty much eliminates this problem.

It's best to have someone take the readings in the hot pit in mid session. A cool down lap will mess up the readings. If you have to take readings at session's end, push the car hard in the corners but run the engine easy. If you have to come the whole way to your pit, take the readings as soon as you get your helmet off.

The temps drop at different rates outside/inside vs the center.
If you get to see realtime data (12 sensors mounted on the car taking temps while running), you would see why taking the temps right away helps.

Crepitus

Print out some tire temp forms and keep them on a dedicated clip board. Reading with in a few seconds after pulling off the track is important. A cool down lap is good for every thing except tire temps. If you can have the same person take them the same way with notes every time the car comes off the track that would be great. Turning the wheel can make it easier to get to the tread. A realtime readout like Bill mentioned was a huge revelation for me. I wish I had a setup like that. There a a lot of things that cloud evaluating readings. A lot of camber and toe will make the inside look like it is carrying more load in the corner than it really is. Finding a nice looking temp balance is good but that is a over all reading. Focusing on the exact place where the tire needs to be working best is not easy. Especially for you road race guys. I have really enjoyed your threads, Keep us in the loop!

BryanPendleton

real-time tire temps ftw: http://www.techmor.com/ir-tire-temperature-kit/



Actually I have been looking at the following budget kit for our crapcan racers.

http://www.opti-grip.com/


Just another approach.

Crepitus

^That is a lot cheaper than I thought it would be. The 3 sensor box looks like the slick setup. I had been looking at a thermal imaging package but there is no way I can afford it. As much as I hate the digital/electronic stuff it may be time to start a basic Data Log system for next year.
Thanks!