Looking for reading material on adjusting alignment and tire pressures based on a laser pyrometer reading. Any guidance would be appreciated.

 

Get temp info appropriate for your tires from the manufactuer. Michelin CUP and Pirelli Corsa like 170- 200 deg F. Mine ran 178 -183- 185 outside to inside this weekend. Measure this right after hot laps - no cool down! Imagine the tread cut into thirds, measure all three outside, middle and inside portion. The outside and middle should be close - within 10 degrees ideally less. The inside can be 10 degrees hotter than the outside this is a result of toe in. The perfect set-up would have even temps but that rerely happens.

Temps should be pretty even across the tread. It is normal for the inside edge to be about 10 degrees warmer than the middle due to toe in. Make every effort to take the reads fast - the outside cools fast! and keep a consistent distance between the pyrometer and the tread. This will probably prompt the guys who prefer the needle type probe to chime in about the superiority of their tool

If the temp is low in the middle the tire is probably underinflated. If it is too high then reduce pressure - 2 lbs max per test.

If the temp is highest on the outside third you need to check alignment. It could be a lack of camber or, a toe condition. Observe tire wear too, not enough negative camber will have the outside wearing much faster then the rest. A too high reading onthe inside also suggests an alignment problem - perhaps too much toe in or too much negative camber.

Hope this provides a start.

 

Bob: I agree with what you wrote but interpreting tire temps after pitting can be quite difficult. The track configuration is always going to influence the temps you get. For example, if you have three hard rights befoe the pits, the right tire temps will be wrong while the left temps might cause you to add too much camber to even the temps but in straghtline braking, you may be overcooking the inside.

What you really want, is real time 3 position temperature monitoring to look at temps during laps. I have one now and will have two installed shortly.

 

CC I agree. On the other hand he has a laser pointer pyrometer. Track config affects the readings for sure but when you see say 180-182-186 on the left side and 170-173-177 on the right, one might consdier the last few turns....!

Best,

 

The laser will make it much more difficult. You really want an insertion probe sensor.

 

CC - I quote my above post:

"This will probably prompt the guys who prefer the needle type probe to chime in about the superiority of their tool".

 

Bob, yes, but you must admit insertion is preferable ... yes?

Wait a second ... what are we talking about here ... oh yea, temperature probes.

 

CC,

Where did you purchase the temperature probes from and what was the cost?

thanks,
Adrial

 

Hmmm...

So I don't even really need to chime in, eh Bob? My "tool preference" has been well documented.

Well, Jim;

Taking accurate temps is indeed a tricky task. There are a lot of factors, some mentioned here. Having an infrared pyro doesn't make it any easier. They read the surface, not under the cap ply where the heat is focused. They are quite useless for keeping tires healthy (properly inflated) because they don't measure the point of concern. Once you know you are in a safe range, they work OK, but only for optimizing "chemical" grip (getting the rubber hot), and only in a very general sense. Real time is the key, and this is not generally feasible.

Do a search. This has been discussed extensively before.

 

This is what I use, it works great for both rotors and tires and is cheap for what it can do:



DC Volts: 0-200mV, 2V, 20V, 200V, 1000V
AC Volts: 0-200mV, 2V, 20V, 200V, 750V
DC Amps: 0-10A
Ohms: 0-200 ohms, 2K, 20K, 200K, 2M, 20M
Hz (freq.): 0-200. 2K, 20K
Secondary Tach: 0-10,000 RPM
Dwell: 3,4,5,6,8 cylinders
Temp: C and F to 1500
Duty Cycle (%Dwell): 0-100%
Continuity Beeper
Diode test
Battery test
External adapter

http://www.esitest.com/cart/1025.html

 

I use this one on my son's kart:
http://www.longacreracing.com/catalo...id=875&catid=7
(no, I don't use it on my car )

And Longacre's take on IR/non-contact vs probe/contact measurements:
http://www.longacreracing.com/articles/art.asp?artid=9

 

Adrial:

This is the pyrmoeter I use in the pits. It is the quickest reading probe available (critical for most accuracy and valuable information) as it predicts the final temperature without having to wait for the reading to stabilize.

http://www.longacreracing.com/catalo...id=193&catid=7

For the real time tire temps of my DAS, I think I should point you to my shop as they have all the info:

http://hometown.aol.com/parbrowser/

 

Guys,

Jim asked a question based on the use of an IR pyrometer. I answered it. Telling him to use something else is not an answer to his question is it? Fact is an IR pyrometer can be used. For tires it is not as good as the needle probe, but it is better than nothing at all - a lot better. Lewis the links to the Longacre FAQ were very useful, thanks.

Rgds,

 

$200 is CHEAP?!?! Come on guys, give me the $25 solution. McMaster Carr maybe? Radio Shack? Williams-Sonoma?

 

I did a quick search of eBay and found this new Longacre non contact pyrometer for $79.95:
http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW
That was the cheapest pyrometer listed on eBay.
I'll keep looking.