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Discussion Starter · #1 ·
I do not think we have talked about this, and I don't want to take this for granted for some of the newer autocrossers, but...

It occured to me as I was reading another post that mentioned overheating race tires, that I should share this bit of information--it is especially helpful to those who run heat-sensitive tires like Falken Azenias.

Get one of these at the local garden center



...after each run liberally spray on some plain old H2O on the tires--I do the fronts first then the rears. They will cool off rather quickly and be much better for your next run
(If you are making any heat at all, by the time you finish spraying the 4th tire on your car the 1st tire will be almost dry...)
 

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I've noticed some local guys doing that with Falkens....How hot are tires getting? Can you feel them going away? I've always tried to keep heat in my tires between runs, true I use Kumhos, but this goes against everything I learned about heating tires prior to a run- parking with sun on both sides when possible, warming blankets...(just kidding), etc. How do the European Series guys complete a full race using Falkens??
 

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warming blankets aren't unheard of, certainly!

i've experienced Azenises getting greasy after a few runs in close frequency, i can see where cooling them off would help. but wouldn't the water only cool the outer layer of rubber, leaving the inside warm?
 

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Discussion Starter · #4 ·
warming blankets aren't unheard of, certainly!

i've experienced Azenises getting greasy after a few runs in close frequency, i can see where cooling them off would help. but wouldn't the water only cool the outer layer of rubber, leaving the inside warm?
I dunno for sure. It seems that they cool off pretty thoroughly--certainly enough to make them less greasy on subsequent runs. I watched all of the really fast guys at divisionals do it. What is that saying??? If you can't beat them...
(yet
)
 

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I will be spraying down hoosier too....the repetitive heat cycling kills the stickiness over time.

Hoosiers become less sticky over time, despite having plenty of tread on them.

All serious autocrossers I now with Falkens spray them after every run...It's been proven you cannot be faster run-after-run without cooling the tires....
 

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Again, my question is, does this really apply to anything but a "street compund" like the Falkens
. How do Enduro guys make Toyo, Kumho, and Hoosier last a full race, realizing they are compounded for higher temps?
Sure heat cycling takes a toll on tires, but would it help a Hoosier after the damage is done? Wouldn't cooling them make them cycle more....rather than a fairly constant elevated temperature?
Has ayone put a pyrometer to the Falkens? We have an event this Sunday. I'll take some readings on my Kumhos and some of the Falkens on other cars. Enquiring minds want to know
 

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Discussion Starter · #8 ·
It is certainly more relevant to someting like the Azenias specifically, but as an example, the Hoosier autocrossers or even--just as an example--like the Old BFG R1 "Runoffs" compound could benifit.

The Falkens may not be any hotter than a "R" compound on the pyrometer--in fact I doubt that they will be as hot--the point is that they dont like the heat that a "R" tire does and will get greasy and inconsistant if pushed at elevated temps for too long.

This post was mainly intended to enlighten the Azenias guys, with perhaps a few other types benifiting.
 

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Right, I wouldn't expect them to like heat like a R tire, just curious where they go away, as I kinda liked the Contis for autoX and they got pretty warm (ripples). Long time since I played with a pyrometer at an AutoX. I'll try and post what I find after this weekend.
 

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Discussion Starter · #10 ·
look forward to the info...
 

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Again, my question is, does this really apply to anything but a "street compund" like the Falkens
. How do Enduro guys make Toyo, Kumho, and Hoosier last a full race, realizing they are compounded for higher temps?
Sure heat cycling takes a toll on tires, but would it help a Hoosier after the damage is done? Wouldn't cooling them make them cycle more....rather than a fairly constant elevated temperature?
Has ayone put a pyrometer to the Falkens? We have an event this Sunday. I'll take some readings on my Kumhos and some of the Falkens on other cars. Enquiring minds want to know
I share that query as well. What sort of course length and interval are you guys running? Sure, a lot of R compound guys with heavier cars cool rubber with water, but that's with 90 second courses and reasonable intervals and very high ambient temps........but the goal is to maintain a temp, not cool the tire too much. For the Victoracer, everyone claimed it ran better at a temp slightly cooler than Kumho recommended, around 160* +-
if my brain isn't farting.

I'd imagine ambient would need to be close to triple digit before I'd not want the most heat to be retained between autcross runs in a street tire like the Azenis, especially since the run length people usually report around here are incredibly low..........but hey results are results.......hmmmmmmm.......I never replaced the pyrometer I drove over.


In talking to few tire dudes from Toyo and Kumho about rheacer's question in the past, they both shared that road course temps would definitely be higher, but then stabilize if the car wasn't overdriven. Both driving technique and set-up is then obviously used to stabilize the temps as much as possible.......as the car and driver take the tire out of that "window".....degradation in performance and life is then exponential.

So I'll guess that you should think that the water could be used to stabilize the tires temp through a set of autocross runs to keep it in it's zone........but Azenis on 40 to 60 second courses?? Yikes....I'm still perplexed on how they are overheating in that environment.


but as rheacer and ZTS alluded to, mr. pyrometer doesn't lie.
 

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Your are correct sir.
While the V700 tread compound operates well over a broad temperature range, it is most effective in the 160° to 200° F range.
From past experience, I don't get near those temps at most (any?) events (ours average 45-60 second). I don't remember ever getting them to the point I couldn't hold my hand against them, but still see ripples so they must be getting close. Stay tuned.
 

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This cooling tires after a run is getting out of hand
. Saw a guy on Hoosiers doing it this weekend...as were 2 of the Falken guys. Didn't get to check anyone else's tires between runs, but I did manage 160+ degrees in both fronts-rears stayed around 130-135. We ran 5 runs on a 37-38 second figure 8 course- second gear the entire course with 20-25 minutes between runs. Did manage to wear down second rib from outside on drivers right on FULL tread Ecstas-bad choice.-last corner was a tight 90 degree right. Ambient temp was 93-96 degrees, tires cooled to 110-111 fronts and rears cooled to to 95-97 -just above ambient. Fronts would gain 2-3 lbs of pressure, rears about 1 lb. Ran 38 front and 36-37 rears. I'm thinking this was pretty optimal for the day. I still don't see the reasoning here, other than "everyone else is doing it".
 

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Discussion Starter · #14 ·
Were the guys you saw some of the "top" guys, or just "also-rans"? This whole thread was started because I noticed some of the top STS/Falken guys at a CENDIV doing it--and it seemed like a good idea as it is pretty well established that Falkens do not like to be real hot (because they get greasy)... Now that you mention it, though, some stock class drivers with Hoosiers were doing it too--Miatas and new MR2s that I recall seeing...
 

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.. Ambient temp was 93-96 degrees, tires cooled to 110-111 fronts and rears cooled to to 95-97 -just above ambient. Fronts would gain 2-3 lbs of pressure, rears about 1 lb. Ran 38 front and 36-37 rears. I'm thinking this was pretty optimal for the day. .....
hmmmmm....well there is real data to chew on.....and I am at a loss why anyone would want their tires cooler than what you noted on that day.
I could see on a day with maybe a 90 second course and small intervals, but otherwise


I guess another way to ask is.......how would any tire, the Azenis included, grip better at or close to ambient instead of a bit higher temp? I don't see how they could?

and in Dave's example, the "watered" tires could have easily been cooled even more than that......maybe this is a good "secret" but I having a hard time wrapping my surfer brain around the logic of it
 

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I use an infrared surface pyrometer. In my experience, Azenis start to get greasy at around 140. I've had them as high as 165 at autox and 180 at Watkins Glen. I've heard that DOT-Rs like 180-200.

The 165 was after an immediate back to back run at a mirrorkana event. The asphalt temp was 110. Our first run was a dead heat, and in the second, I lost by at least 50 yards.

A mirrorkana (not sure of spelling) is where two cars start at the same time on a full loop autox course going the same direction, but half way around. The first one to get back to your own start/finish line is the winner.
 

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Discussion Starter · #18 ·
IA mirrorkana (not sure of spelling) is where two cars start at the same time on a full loop autox course going the same direction, but half way around. The first one to get back to your own start/finish line is the winner.
Kind of tangent to the thread, but that sounds like Big FUN--almost like a ProSolo
 
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