Heat cycling DOT-R's. Does it help?

trekkor · 04-07-2007, 03:12 PM

I don't really know?

I have a brand new set of 710's ready to go for Monday.
I was planning on putting them on the car right now, getting them up to 150-160 degrees and then loading the car on the trailer. They'll have two nights to cool off before my first session.

What is the benefit? Is it worth the effort and why?

I went out on brand new rubber at TH and the 710's felt a little skatey during the first session.
After that, they felt great and still produce very good lap times for me. They are just getting down to the wear bars. Likely north of 40 heat cycles and a few a/x's.
I'll still a/x on them during the morning runs until corded.

Same with that last set of R-Hoosiers. Ran 'em new at Laguna last year.
40 heat cycles later as well, they are just a little off the pace, but still fun to drive on.
They were only 1/2 a second off a fast fellow 914's pace at Altamont autrcross on good "A"-Hoosiers.
I was able to match my best lap times a Laguna compared to when they were new but they were 3 seconds off the pace at Sears.

I may run the Hoosiers at Reno Fernley on the first day.

I'm feeling a little lazy right now. I just woke up from a nap.

I'd rather put the tires on in the paddock after the driver's meeting.

Now, if I have something to gain...

KT

ted · ted's Garage

I asked our local Kumho sponsored SCCA AX champ if 710s need the initial heat cycle and rest period. His response was "why waste a good layer of rubber". On his advise I just run'em.

Jack Olsen · 04-07-2007, 05:00 PM

R-Compound isn't a precise term -- you really need to look at it on a tire by tire basis. Usually, you can email the particular manufacturer's rep to get suggestions on pressures and things like heat cycling and shaving.

trekkor · 05:35 PM

I'm just trying to see if heat cycling will make them last longer.

After 40 heat cycles, does it really matter?

KT

Jack Olsen · 04-07-2007, 09:21 PM

It depends on the tire. Some don't benefit from it at all. Some do. There's some skepticism about the type of off-the-car heat cycling that Tire Rack does. The accepted method seems to be a single hot session, followed by 48 hours of the tire off the car and on its side.

jaydubya · 04-08-2007, 05:04 AM

Not sure about V710s but heat cycling the Hoosier R6 (on the car, at the track, wait at least 24 hrs) makes a big difference in both consistency and longevity for me.

I would do whatever the Kumho engineers say though. As Jack mentions, not all r-compound tires are the same as far as care and feeding.

Plavan · Plavan's Garage

I heatcycled the V710's one time, and another without. can't tell a difference. The V710's heat cycled out long before the tread is gone, so why waste a heat cycle?

trekkor · 04-08-2007, 12:12 PM

Thanks for the replies.

I'll be going out on stickers tomorrow morning!!

KT

cstreit · cstreit's Garage

Quote:

Originally posted by Plavan
I heatcycled the V710's one time, and another without. can't tell a difference. The V710's heat cycled out long before the tread is gone, so why waste a heat cycle?

I have the same experience. I heat cycle out tires long before I wear out the tread... I think this is more useful on heavier cars that cord out tires before heat cycling them out. The only time I've seen cords on my racecar (1950 lbs dry) is running them for 6 hours in an enduro....

Now I did have some problems with the V700's if I didn;t heat cycle them, got some blistering if I didn't go easy on them the first few laps, but didn't have that issue with the V710's

Mahler9th · 04-09-2007, 07:31 AM

It is always BEST to heat cycle ANY DOT sticky tire or slick. What you gain is the part that depends on the tire. Understanding and caring for the tires is critical to going faster, and heat cycling is a natural part of that. However, what you gain is dependent, and the hassles involved may not be worth the gain.

I would never use a set "go fast" DOT tires like the Hoosiers without heat cycling, unless due to logistics I had to. Same for slicks.

Do some reading to find out what heat cycling does to the rubber. Read articles by real experts/engineers. Its not all about prolonging tread life. Most of thos folks don't read or post to internet BBs.

- Mike
"It's all about the tires."

trekkor · 04-09-2007, 10:30 PM

Well I ran at Laguna today.

Really fun!! But... My lap times were only a split second faster than the 40 heat cycled Hoosiers and 710's from a few weeks ago.

I'm at a loss.

KT

Jack Olsen · 04-10-2007, 10:31 AM

Whenever you change tires, you're usually looking at slightly different optimal suspension settings that will work with them. Also, it usually takes some getting used to driving the car with the different-behaving tires.

trekkor · 04-10-2007, 04:16 PM

These are the third set of 710's on my car with no suspension changes.

Same 26 PSI cold.

KT

Jack Olsen · 04-10-2007, 05:14 PM

Ah, I thought you were moving to slicks.

Different days at the same track -- especially with temperature changes -- can make a big difference.

Plavan · Plavan's Garage

Quote:

Originally posted by Jack Olsen
Ah, I thought you were moving to slicks.

Different days at the same track -- especially with temperature changes -- can make a big difference.

2nd that

trekkor · 04-10-2007, 09:09 PM

I'll be at Sears on Monday. If I can't get below my best of 2:00, I'll be sad.

KT

trekkor · 05-19-2007, 09:59 AM

2:01 with passenger...

I'm sad.

KT

trekkor · 05-19-2007, 10:00 AM

My best lap times on all tracks come in the fall.

KT

cbeers · 05-20-2007, 07:50 AM

Whatever, next it will be the gearing

Trek, a lap around the track with you is always fun

-Chris

scca_ita · 05-20-2007, 08:26 AM

I think some of the terms are being interchanged (heat cycling through a machine and Shaving). Heat cycling on a tire machine does NOT remove material. It brings the tires up to temperature so that the top layer of oil is burned/rubbed off the tire surface, leaving very nice sticky rubber that is ready to go. This oil residue is part of the tire molding process. If you are running on a track with fresh tires, I would perhaps save the $15 per tire that it cost to heat cycle them. On a track it is easier to operate your race car at 70-80% to gradually scrub the tire surface. This does remove material. For AutoXing (which is what I am using the tires for) there is not enough time to get heat into the tires unless you do multiple runs at near 100%. It is also hard to get a uniform scrub with fresh greasy tires on an AutoX.

Heating tires on a heat cycling machine is not Shaving the tires which removes material. IMHO Heat cycling will add life to the tires because they are ready out of the box.