2000BSME

If I went to an event this weekend, and spent four 15 minute sessions for each day of the weekend (sat, sun), does that mean I have 8 heat cycles on my Hoosiers? I had tire rack heat cycle the tires before they were shipped.

could someone clarify for me? thanks.

freefall

yes - 8 cycles last weekend.

AU N EGL

Heat cycle is each time the tire is up to opperating temp and pressures.

0 to 3 heat cycles for acutal W2W racing. - 4 to 10 heat cycles for good track performance 15+ still ok to use and have more grip then street tires. Tires get hard and slide more.
tread depth has nothing to do with heat cycles.

use the tires for track days until you cord them, just watch the sliding.

wtknght1

And OBTW, don't bother having Tire Rack "heat cycle" them for you. It's a big waste of time and money. And, unless you are racing on street tires, I wouldn't shave them either.

Also don't bother with cryo'ing your rotors...or anything else for that matter.

Just FYI - A tire normally has 1 or 2 'golden laps' in them. When they are brand new ("stickers"), the first or 2d hot lap you run will most likely be their quickest - i.e. qualifying! After that, they drop off a little bit but are more consistent.

For the guys running Kumhos, the golden lap(s) is/are basically the 1st and 2d flying laps and then they lose a little bit. Once you qualify on those "sticker" (or new) tires, take them off and let them cool, if at all possible. Once they cool, they come back really strong and are ready to race. I try to race on the 3d or 2d heat cycle...but have raced Nationals on as high as the 6th cycle, and they are still damn fast tires.

Some of the guys in T1, who are running Hoosiers, are actually racing on new tires. They seem to hold up pretty well. I have race the Kumhos when new and they do incredibly well too, but I like racing on a tire that's been cycled at least once. They just seem a bit more consistent to me.

2000BSME

so, what you are saying is that one session of 60 minutes is better for tire grip than four sessions of 15 minutes? I haven't hardly wore down my R6's at all, from the probably 8-10 heat cycles I put on them this weekend. Is the performance all downhill from here on out?

thanks

yellow01

Chris,

Regarding tire rack heat cycling - you mention 1 to 2 hot laps (qualifying) then remove and let cool. Many of us DE-ers don't have this option since we may hit a DE weekend with a new set.

Do you still recommend skipping the tire rack cycling?

Thanks!
Jon

JiminVirginia

I found this thread on SCCA Forums:

http://sccaforums.com/forums/thread/182527.aspx

The Tirerack link refers to the chemistry of it all. I'm struck by the references I see to the cooling/resting period as what defines a heat cycle.

95jersey

For the DE user, heat cycle will make the tire last longer from a tread only perspective. This has nothing to due with performance, per say. But I simply need my tires to last as long as possible no matter how they grip.

A racer won't care about heat cycles because he is done with the tires before they are near the wear bars. On the other hand, I try to get a whole season out of a set of tires (6-8 days) regardless of performance.

I personally don't have the ability to change multiple rims at the track so letting them cool down for 24 hours is not an option. Also, you'll never get the tires up to proper temp on the street, and if you are, you should be locked up because you are driving WAY too fast for the street.

So bottom line, in this scenario getting the tires heat cycled from Tire Rack is a plus.

wtknght1

Let me say this again. Heat cycling from Tire Rack does not help tire life, performance or anything else but their wallet. I love Tire Rack, but their heat cycle is simply not the same as a track heat cycle. The track simply heats it differently and stresses the rubber differently.

I've tested it and there is no difference. Don't waste your money.

If you don't have the time/spare wheels, etc. to take them off and let them cool, you'll still be OK because when you come off track, the tire immediately begins to cool. The longer you can let the tire cool, the better tread life you'll probably have. Tires are so damn good these days though, that you'll probably never notice the difference over the life of the tire.

The best answer for long tread life is not to over drive the car. Small slip angles are enough for really fast lap times and good tread life. If you are really sawing at the wheel , you're probably over driving the car. Back off just a bit, be smoother and I'd be willing to bet your lap times will improve (especially over the entire session), and your tires will really last!

Jason

http://www.amazon.com/gp/product/076...e=UTF8&s=books

provette67

Does a session on the track equate to 1 heat cycle?If so what happens when some sessions are 20min. and some are 40min. does it still count as one heat cycle?What about auto cross heats cycle,35sec. run as apposed to a 60sec. run are they still just one heat cycle???

wtknght1

Regardless of the length, it's still just one cycle. Most of the tires I sell have about 3 or 4 laps for the qual (one cycle), 3 or 4 more laps for the warmup and brake bedding on Sunday morning (cycle #2), and finally the race - normally 14-26 laps (cycle #3).

I may do a test session or two on them during the next national weekend, but that's about it.

Generally speaking, anytime you use a tire, be it on the road or auto-X or track, you've taken it thru a heat cycle. The tire slowly loses it's ability to grip over it's life of heat cycles...and usually gets harder. It's not unusual to see Auto-X tires with 20, 30, 40 or more total heat cycles though because you simply don't wear the tires down to the cord as fast.

Another thing to keep in mind is where the tires were run. Tires from Road Atlanta or VIR or nice tracks like that don't wear the tire down as much as some place like Roebling for instance. 10 heat cycles at Road Atlanta may only wear the tire down to half tread, while 10 cycles at Roebling and you may see cord showing!

AU N EGL

One 15 min, or one 20 min or one 40 min session = one heat cycle. As Chris mentioned above.

Each time the tire is up to opporating temp and PSI is ONE heat cycle.

Scubbing Race Tires.

"Running new tires though an easy initial heat cycle called 'scubbing' allows the rubber and the cords to settle together more uniformly and relaxes some of the high-stress areas. The tires become more resistant to stress the next timethey are used. After scrubbing, tires need a minium of 24 to 48 hours to relaz and reform the stretched and broken bonds. As a absolute minium most race-tire manufacutres recommend a few laps at less-then-race speeds to condition a rire before it sees maxium stress.

Generally the best way to scrub in a new tires is to put them though one heat cycle, gradually loading them up but avoiding sliding. A couple of laps, minutes if the track is short, will do the trick, build up to a final lap almost as fast as a race lap. To complete the heat cycle the tires can cool naturally sitting still in the paddock. It is always best to let new scubbed tires cool while they are unloaded, so either take them off the car or put the cur up on jack stands."

Source: p128 of "The Racing & High-performacne Tire" by Paul Haney

http://www.amazon.com/gp/product/076...e=UTF8&s=books

jkonkle

Okay so then if you do get them heat cycled - wether it be at tire crack or on the track, possible a skid pad day before the weekend - then you are preparing the tire to, and I quote from the book...

The tires become more resistant to stress the next timethey are used.

Am I to assume that this stress would be in the form of friction, thus allowing the tire to perform better initially and over the entire use?

It's been a while since I took organic chemsitry, but I lean more toward having some sort of heat-cycle as opposed to none. Either way, $10 per tire isn't exactly a rip-off. Unless you simply don't feel the difference.

JK

AU N EGL

Yes a the first heat cycle or scubbing in of the tire should be used. The question remains is it best done on your car as you get use to the tires or have some one else do it ?

I think it is best for you to do it in your car. I also wonder if living out in the county with some nice no traffic curvey roads or just take your first session of the first day easy?

dmwhite

i vote for doing it yourself...i mean, who knows what tirerack is really doing when they "heat cycle" your tires for you...scrub in procedures might vary from tire to tire, hoosier has very specific instructions for their tires...

as far as doing it on country roads, it might work for some tires, but for hoosiers, imho, its best to do it on a track (controlled environment) where you can follow their procedure...

as others have mentioned, its not absolutely necessary to scrub tires in, for hoosiers, it depends on if you want them to last longer (and be more consistent) or if you want to take advantage of the "golden lap(s)" for qualifying...

when i ran toyos, i would just slap them on and go...

also, imho, buying new hoosiers for DE's is a waste of money...get a tire that will last longer or buy scrubs if you can

wtknght1

For just DE stuff, I doubt you'll ever know the difference one way or the other. The tire rack heat cycle is just a waste of money though. Tires are so good these days, that you can just bolt them on and go. But if you really want to heat cycle your new tires, just send 'em to me and I'll do a few qualifying laps on them and send them back to you.

We almost always qualify on sticker tires to take advantage of those golden laps. I have raced on sticker tires though (7 different brands to date, and different versions of those brands as well) and didn't notice any real difference in tire wear as opposed to racing on the 2d or 3 cycle. I just think that the 2d or 3d heat cycle tires were a bit more consistent to me.

AU N EGL

I agree with Dave and Chris. New tires, most of us WELL never feel the difference. Many times we attempt to over analyse a situation or parts of the car when just more and more seat time to really learn our and ask our cars to do.

dmwhite

i'd also like to offer up my heat cycling services...of course i need bmw fitments, specifically 245-40-17...i'd be more than happy to do 1-2 laps on them for you, out of sheer generosity, i'll do it for free!

freefall

so, if you pull off track and put tire warmers on, keeping the temps up, would the day be considered a single heat cycle or has enough cooling taken place on the cool-down lap that the cycle is already complete?