Tire PyroMeter Tuning Guide
 

A tire pyrometer is a very valuable device for the track especially when your trying to setup your car. A basic tire pyrometer comes with an electric headunit wired to a heat sensor that is usually inside a needle. You push the needle just a bit into the tire to get an accurate heat temp reading. You should take readings as soon as the car stops from its lap to make sure your readings are accurate and the tire has had no time to cool down. From the moment you stop coming off your hot lap you will have about 30seconds till the temps change and that's another reason you have a needle.

You will be measuring three point on the tire. See the chart I drew below.

http://img443.imageshack.us/img443/5...erchartxn0.gif

A good basic meter is something like this:
http://www.longacreracing.com/catalo...st.asp?catid=7
This company makes very reliable products and is trusted by many racers/teams.

Notes:

• For correct camber the two edges of the tread should have equal temps.

• For correct tire pressure the temp of the center should be equal to the average of the edges.

This will help you save tires too! If you have some extra cash you want to spend You could buy electric tire heaters to save the tire warm up laps giving you ever more useful life out of the tires.

Special thanks to Fred Puhn

You don't have to try for exactly equal temps side to side. It's perfectly fine to have the inside be 10 degrees or so hotter. For instance that second spread would be just fine and would be normal for a lot of properly set up cars.

Most racing organisations ban tire warmers on grid. You could use them in the pits, but by the time you grid and get on track the tires will have cooled significantly, mostly or totally negating any benefit. One thing that some racers do use to help with first lap performance and consistency is to have bleed off valves set at the desired tire pressure. That way your pressure on lap one will be equal to the last lap for more consistent feel and handling. It's a much more economical thing to do compared to tire warmers, as I think they're usually in the $1k+ sort of price range.

+1 I'm reading that book too and was wondering about this, chart nicely done :)

that's a really nice job explaining how you do tire temps. it is correct that you need to get them ASAP. (do the pressures after the temps... keep a log)' i also like the Longacre pyrometer.

that said, part of the info is, at minimum, confusing.

part of the reason you use a pyrometer is to set your suspension to go fast.

fast is 20 degrees hotter on the inside of all four tires. if you don't have it, you are going slow. you do make the point that a hotter inside tire is a function of negative camber. you are certainly correct.

in addition to reading each tire i take all three temps on each tire add them and divide by three to get the average of all 4 corners to get a feel for overall suspension trim. i also look at total temps front to rear and left to right.

overall a really nice post but it would be helpful if we could edit it.

howard

Depends on the association but a lot of the PCA guys use them just in the pits and they say it helps..does it really? I dono, they have insane budgets for the yr. As a track junkie with extra cash I'd love to use em. :rlaugh:

Bleed valves are a good recommendation I almost forgot to mention those, thank you! As advice to someone who doesn't use them, check your tire pressure after making stops.

If you can provide me with "FAST" data numbers (enough to show a couple overall suspension trim averages), I can plug them into my cart and have one more scenario to illustrate. I can even go as far as making an excel formula sheet that will let you just plug #'s in and it will calculate for you. I'm very open to idea of adding more charts.
Thank Howard:icon_tup:

THanks and indeed an excellent book but I was hoping for him to explain high and low suspension frequency so that maybe I can get myself into dynamics suspension tuning. You know for the price of $3 on half.com its an excellent read.

Actual tire temps that work best will be somewhat dependant on the tire, as different tires operate at different temps. For instance if we're comparing a Hoosier A6 to an R6, they look the same, but the A6 is meant to operate at a lower temp so that it's sticky for autocross. Consult your tire supplier for proper operating temps. Your temps taken in the pits will be a bit lower.

If you really want to get fancy, mount some thermal imaging cameras in the wheel wells.