Story by J.G Pasterjak • Photography as Credited
As everyone’s favorite fictional blonde trespasser can attest, ideal temperature is a key to satisfaction. And while having tires that are too hot or too cold won’t necessarily lead to a bear mauling, ensuring that your rubber is in the “just right” range is crucial to both performance and longevity.
But first, why does …
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In case anyone wants to get in on the Pyro game, I have a few good used Longacres I would let go for not much money.
If you want a reasonably priced pyrometer, get one of these probes and plug it into any digital multimeter that accepts K-type thermocouples:
https://www.amazon.com/gp/product/B07H5H1YV9/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
In reply to ShinnyGroove (Forum Supporter) :
That's very reasonable. Thanks for posting it.
Solid work here, JG. On the money with all points, and concisely delivered.
Some additions, if I may:
1) Regarding heat cycling: you allude to it when mentioning "preconditioning", but don't specifically call out the benefits of an initial heat cycle. Many tires really need a solid initial heat cycle to deliver optimal grip. We have noticed this in our tire testing and now incorporate a pre-test scrub/cycle day to allow all test tires to perform at their best during tests. Yokohama A052, Falken RT660 and Nankang AR-1 are some that change dramatically after that first cycle.
2) There are two basic kinds of grip...the mechanical interlock that you describe, but also adhesive grip. And while heat-induced softening for better mechanical grip is a hallmark of racing tires, so is adhesive grip. The latter is something that street "motorsports" tires do not typically deliver. Adhesive grip works on all surfaces, including those that are polished or smooth. Think of it as "hot glue". That's why the performance delta between street and race tires on some tracks is much larger than others. COTA is a great example of this. For more info on grip components, reference Paul Haney's book, The Racing and High Performance Tire.
3) Electric tire warmers can also be very helpful when you have a car that does not warm it's tires evenly. On our One Lap CRX, we've been using a set of Chicken Hawks for over decade, but only on the rear of the car. There is so little weight back there that the front tires come up to temp way before the rears. This creates a vicious circle where the front is sticking well, but the rear has no grip to generate load to generate heat to generate grip. Adding heat to the rears pre-session allows the fronts to come up to match nicely w/o the car trying to kill you. We do this for NASA TT4 with Hoosier R7's.
4) That temp chart is super useful when you have variable weather throughout a weekend of sessions. Even if you know your typical pressure rise, you need to account for different ambient starting points to hit those target absolute hot pressures. This is especially true for overnight endurance racing like the Thunderhill 25H. Pre-heating with electric tire blankets are one solution (we use these for the Honda team I crew chief for). Or account for it manually.
Noted IMSA crew chief and race engineer Jeff Braun, with thousands of hours of professional enduro experience, suggests a simple rule of thumb...1 psi per 10 degrees of ambient temp. So when you're watching those guys set pressures for the next pit stop during the frigid early morning hours (electric warmers are not allowed in IMSA) you'll know their secrets.
In reply to stylngle2003 :
I see that offer to sell was a long time ago. I would buy one if still available.
In reply to edmknapp :
Sweet! Send an email to William.nolden at gmail and I'll send you some info about what I've still got. Thanks!
I built this contraption for getting inner/center/outer temps all at once. It's not a high dollar setup so it's not instant accurate so i just hold it on the tire and count to 10, snap a pic and do all the tires then go back and look at the pics to analyze.
