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Heat cycle questions

215
210
Exp. Type
HPDE
Exp. Level
Under 3 Years
SoCal
Hey everyone. Along with my latest suspension upgrades, I made the move to 19x11 square BC Forged wheels for my S550. I was also able to pick up a set of 305/30R19 ContiForce Contacts from a member of another forum for only $500. The price was too good to pass up. He purchased them on clearance from Tire Rack and never used them. Though they still have the stickers on them, they are 4 years old so hence the price.

The main question I have is about heat cycles. From what I've been reading, heat cycling new tires and then letting them rest for 24 hours or more will extend the life of the tires. What I can't get a definitive answer to is, what constitutes a heat cycle? Would one day spent at the track be considered one heat cycle or would each individual session (approximately 7 or 8) be considered a heat cycle?

Also, would it even be worth the effort to try and heat cycle the tires on the street?

Thanks in advance for you input.
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Hey everyone. Along with my latest suspension upgrades, I made the move to 19x11 square BC Forged wheels for my S550. I was also able to pick up a set of 305/30R19 ContiForce Contacts from a member of another forum for only $500. The price was too good to pass up. He purchased them on clearance from Tire Rack and never used them. Though they still have the stickers on them, they are 4 years old so hence the price.

The main question I have is about heat cycles. From what I've been reading, heat cycling new tires and then letting them rest for 24 hours or more will extend the life of the tires. What I can't get a definitive answer to is, what constitutes a heat cycle? Would one day spent at the track be considered one heat cycle or would each individual session (approximately 7 or 8) be considered a heat cycle?

Also, would it even be worth the effort to try and heat cycle the tires on the street?

Thanks in advance for you input.
Every time the tire comes up to operating temperature and then cools down counts as 1 heat cycle. It is important not to bring them up to temp or cool them down too fast.
A handful of slow laps picking up speed each lap until you are at threshold and then take them off the car and let them cool for AT LEAST 24 hours.
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Here is what HOOSIER recommends:

The first laps for the tire are critical for setting up the durability and competitive life. The first session should consist of no more than 10-15 minutes of running. The early part of the session should be run at an easy pace, with the speed gradually increased until the end of the session. The final lap should be run at the fastest possible speed. The intent is to achieve maximum tire temp on the last lap. At this point the car should be brought in and the tires allowed to cool at a normal rate. During the initial run-in process, the inflation pressure should be 3-5 psi higher than you would normally use. The best progression would have the driver taking 4-7 laps to accomplish this break-in. Each lap should be approximately 7-10 seconds a lap faster than the previous lap. The goal is to have the tire temp as high as possible on the last lap without “shocking” the tire during the warm up laps. In essence, no wheelspin, late braking, or sliding. The last lap should be at, or very close, the maximum possible.
 
215
210
Exp. Type
HPDE
Exp. Level
Under 3 Years
SoCal
Here is what HOOSIER recommends:

The first laps for the tire are critical for setting up the durability and competitive life. The first session should consist of no more than 10-15 minutes of running. The early part of the session should be run at an easy pace, with the speed gradually increased until the end of the session. The final lap should be run at the fastest possible speed. The intent is to achieve maximum tire temp on the last lap. At this point the car should be brought in and the tires allowed to cool at a normal rate. During the initial run-in process, the inflation pressure should be 3-5 psi higher than you would normally use. The best progression would have the driver taking 4-7 laps to accomplish this break-in. Each lap should be approximately 7-10 seconds a lap faster than the previous lap. The goal is to have the tire temp as high as possible on the last lap without “shocking” the tire during the warm up laps. In essence, no wheelspin, late braking, or sliding. The last lap should be at, or very close, the maximum possible.

Yep, I have read all that. I just wasn't sure how to keep track of heat cycles with a set of tires. Knowing now that it's every session helps.

Unfortunately I don't have the luxury of having multiple sets of tires (or wheels) so that I can heat cycle a new set at the track and then run a different set afterwards. I have to run what I brung. That is why I was wondering if it was worth the effort to try and heat cycle these new Conti's on the street or not. I can't imagine getting them up to track temp, but if it helps I will do it. If not, I will just have to run them as is.
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Yep, I have read all that. I just wasn't sure how to keep track of heat cycles with a set of tires. Knowing now that it's every session helps.

Unfortunately I don't have the luxury of having multiple sets of tires (or wheels) so that I can heat cycle a new set at the track and then run a different set afterwards. I have to run what I brung. That is why I was wondering if it was worth the effort to try and heat cycle these new Conti's on the street or not. I can't imagine getting them up to track temp, but if it helps I will do it. If not, I will just have to run them as is.

Most of us have that same dilemma.
Same with bedding in new brakes pads and rotors.
Tire rack has a service that heat cycles the tires before they ship them which a lot of us use. I understand that won’t help you here but in case you didn’t know about it......there’s that.
As far as heat cycling old/new tires on the street first, I don’t know what would happen. The rubber and cords have been deteriorating for a long time now and old/new tires sometimes fail when brought up to maximum threshold. (Ask @antman450) I think I’d rather try to keep them in a controlled environment like a race track.



Sent from my iPad using Tapatalk
 
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Just take it easy your first time out with the tires. Next session pick up the pace and put the tires to use. Probably not as good as a "laboratory" controlled heat cycle but will work just fine for your bargain priced tires.
 
215
210
Exp. Type
HPDE
Exp. Level
Under 3 Years
SoCal
As far as heat cycling old/new tires on the street first, I don’t know what would happen. The rubber and cords have been deteriorating for a long time now and old/new tires sometimes fail when brought up to maximum threshold. (Ask @antman450) I think I’d rather try to keep them in a controlled environment like a race track.

Sent from my iPad using Tapatalk

Well then... That's not the most encouraging news. I wasn't expecting them to perform 100% like new, but I wasn't thinking that they may fail either. Hmmm....
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
Well then... That's not the most encouraging news. I wasn't expecting them to perform 100% like new, but I wasn't thinking that they may fail either. Hmmm....
They may be perfectly fine, just not as fast as a fresh tire.
However, depending on the age and how they were stored, they could fail without warning.
It happens. I've had it happen to me and I've seen it happen to others.
Sometimes they just blister, sometimes the cords separate and produce a bubble.
Sometimes they blow at speed as in what happened to @antman450 just a few months ago.
I'm not here to be a buzzkill...I'm just here to tell you to be careful, break them in gently and check them carefully after every session. Hopefully, they will be just fine.
 
My experience with the only time I have used old tires (albeit mine were older than 4 years - I think 6) is that they blister then explode if you keep running them after blistering. On the other hand, I ran them at full useful speed from lap 2 until they blew. I think you will be fine, but ease them in the first session. I would drive them around for 15 minutes and then jack up the car (or take them off) for 24 hours anyway. This will get them to about 110 F which is enough to loosen up some bonds and let them reshape. Also, make sure if you feel a shimmy (tire blistered) get off the track immediately.

Having said all that, I ran the ones that blew to the full extent I could, but I was at a track where flying off at 100 MPH did not scare me in the slightest. A track with walls and not a lot of run-off is somewhere I would not run old tires. I see you are in SC, so Buttonwillow, Chuckwalla, and Big/Streets of Willow and I would feel comfortable. Fontana, hell no!
 
215
210
Exp. Type
HPDE
Exp. Level
Under 3 Years
SoCal
I'm not here to be a buzzkill...I'm just here to tell you to be careful, break them in gently and check them carefully after every session. Hopefully, they will be just fine.
I'm here to learn from people more experienced than myself, so no worries about being a buzz kill. I appreciate the honest feedback :)

My experience with the only time I have used old tires (albeit mine were older than 4 years - I think 6) is that they blister then explode if you keep running them after blistering. On the other hand, I ran them at full useful speed from lap 2 until they blew. I think you will be fine, but ease them in the first session. I would drive them around for 15 minutes and then jack up the car (or take them off) for 24 hours anyway. This will get them to about 110 F which is enough to loosen up some bonds and let them reshape. Also, make sure if you feel a shimmy (tire blistered) get off the track immediately.

Having said all that, I ran the ones that blew to the full extent I could, but I was at a track where flying off at 100 MPH did not scare me in the slightest. A track with walls and not a lot of run-off is somewhere I would not run old tires. I see you are in SC, so Buttonwillow, Chuckwalla, and Big/Streets of Willow and I would feel comfortable. Fontana, hell no!

Thanks for the info. These are dedicated track wheels and tires, so I will follow your recommendations and slowly warm them up on the street and then take them off the car. I'm very in tune with the feel of my car, so if I get any feedback about a vibration I will pull into the pits and check things out. I will not be running my normal pace anyway since this is the first time I've gone to a square setup and I have done some front suspension changes. It's going to take some time to feel out the new handling characteristics and then determine how to dial things in from there.
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
I'm here to learn from people more experienced than myself, so no worries about being a buzz kill. I appreciate the honest feedback :)



Thanks for the info. These are dedicated track wheels and tires, so I will follow your recommendations and slowly warm them up on the street and then take them off the car. I'm very in tune with the feel of my car, so if I get any feedback about a vibration I will pull into the pits and check things out. I will not be running my normal pace anyway since this is the first time I've gone to a square setup and I have done some front suspension changes. It's going to take some time to feel out the new handling characteristics and then determine how to dial things in from there.
Like I said, might be perfectly fine. But if God forbid something bad happened and you got hurt and I knew and didn't say anything......anyway, just be sensitive to any new vibrations. You know, just in case. :)
 
So I have had a chance to read through all the posts on this thread and am still wondering the best way to get a new set of tires to temp NOT on the track. I recently bought the Toyo Proxes RR's from a recommendation (Thank you Pemberton) and currently put them on the car.

The sidewall height does concern me a little as they are just 295/30/18. However, properly aired up they should be just fine. Have to figure out what the best pressure for these are also.

Anyways, today is Tuesday and I need to make sure they are "Near Perfect" for a solid Saturday run! Now I could "try" and get them to temp on the street but that could prove to be difficult as the temps are not to exceed mid 70's all week. In addition, I could also use Friday to ease them in as written about above.

The rest time for the tire will only be maybe pushing 24 hours depending on what time I can get on the track.

Material I have read says the tire needs to reach between 170-180 degrees then taken off and let to rest.......what should I do? Thank you for any help in advance!
 
Hey everyone. Along with my latest suspension upgrades, I made the move to 19x11 square BC Forged wheels for my S550. I was also able to pick up a set of 305/30R19 ContiForce Contacts from a member of another forum for only $500. The price was too good to pass up. He purchased them on clearance from Tire Rack and never used them. Though they still have the stickers on them, they are 4 years old so hence the price.

The main question I have is about heat cycles. From what I've been reading, heat cycling new tires and then letting them rest for 24 hours or more will extend the life of the tires. What I can't get a definitive answer to is, what constitutes a heat cycle? Would one day spent at the track be considered one heat cycle or would each individual session (approximately 7 or 8) be considered a heat cycle?

Also, would it even be worth the effort to try and heat cycle the tires on the street?

Thanks in advance for you input.
A heat cycle is when your tire reaches its operating temp. Not sure on those tires but somewhere around 165 degrees probably. I run five sessions a track day so that is five heat cycles.
 
1,101
1,071
In the V6L
So I have had a chance to read through all the posts on this thread and am still wondering the best way to get a new set of tires to temp NOT on the track. I recently bought the Toyo Proxes RR's from a recommendation (Thank you Pemberton) and currently put them on the car.

The sidewall height does concern me a little as they are just 295/30/18. However, properly aired up they should be just fine. Have to figure out what the best pressure for these are also.

Anyways, today is Tuesday and I need to make sure they are "Near Perfect" for a solid Saturday run! Now I could "try" and get them to temp on the street but that could prove to be difficult as the temps are not to exceed mid 70's all week. In addition, I could also use Friday to ease them in as written about above.

The rest time for the tire will only be maybe pushing 24 hours depending on what time I can get on the track.

Material I have read says the tire needs to reach between 170-180 degrees then taken off and let to rest.......what should I do? Thank you for any help in advance!
Getting a track tire up to temp on public roads will likely have at least one, and perhaps more than one, of three outcomes: You kill yourself, you kill someone else or you lose your license. It takes about 20 minutes of 1g corners to get the tires up to temp. You might be able to do it in a parking lot somewhere, but the noise will probably attract some unwanted attention.

You may be overthinking this, though. Most people don't bother with the "durability" heat cycle - they just get out and drive. And that's what I do. I've broken in four pairs of new tires this month - minimum first outing was a full day at the track with 6 heat cycles. Tire life will be what it'll be.

What is important, though, is to drive them far enough to wear off the mold release agents on the surface of the new rubber before you get to the event. Otherwise it'll be a very slippery first lap or two.
 
4,651
5,258
With regards to tires..
This can be a can of worms, guys forced to run treaded tires will take a new set, cut them down to minimum tread depth and, depending on the application, heat cycle them. what this does is gets rid of the "tread squirm" present in new treaded tires, by...getting rid of the tread. This is for hard core race guys, to me it's hosing away lots of tire life, however, if you have a relatively unlimited budget and a stack of new tires, then go for it.
New tires, and I'm talking race slicks here, along with most treaded street type tires, will be their absolutely fastest when they are brand new, you will always be able to take a new tire and beat a tire 5 laps older, providing the driver and car is the same. This is why you always boost qualifying pressures, so you don't hose away the "filet" of the tire warming them up, get out, get after it and get it done, because you boosted pressures you may have only a 5 lap window before the tires over pressure, then you're done..not going to happen. The pressures are TOO high AND the filet of the tire is gone as well. Most race organizations will not let you touch the car after it presents for qualifying, so you can't dump pressure, the best you can do is come in and sit on pit lane so the pressures go back down.
With heat cycles, it depends on what you want to do for the tires, heat cycle them by bringing them up to temp slowly, and over a couple of laps will do wonders for the longevity of the tire, so if you are planning to double stint or are running an endurance series this may be a way to go BUT.. those cycled tires will never be as fast as a set of stickers right out of the box. The stickers will always be faster BUT will not last as long as the tires that have been cycled....basically name your poison, speed or longevity.
Old tires, clearly these have been heat cycled, (properly or not) so i would just inspect them, and run them, making sure your first few laps scrape off all the funk and the harder "crust" that accumulates on used tires. You may also use a judicious application of Goat Pee, then wrap them in cellophane and place them in a cool dry area to preserve them between uses. Inspect them thoroughly for impact damage or overheating, especially the inside, a lot of times heat bubbles will form there first and you can also see cord separation there as well. It's prolly more important to check the inside of the tire more than the outside.
I do not have a huge amount of experience with treaded tires, but slicks will blister a long time before they come apart in most cases. I've never seen a slick tire just blow up without some type of warning, unless they are impacted by some type of debris or whatever. They will usually rattle your teeth out from the blistering before they blow in almost every case. I have, however brought cars across the finish line first, second and third, with corded tires at both Homestead and Daytona. Normally we run A7s on most tracks, but we've taken the time to see what works and what doesn't, plus Phoenix has a dedicated tire guy that does nothing except tires. A few years ago we were running A7s at Daytona, we were being chased by a BMW that was forced to run A7s because we were and they wanted to keep up. down the front straight the BMW blew the rear tires off the car, the
Mustang finished the race with blistered tires, but finished, barely.. So the deal is, details count in this game. I have to believe the BMW driver was driving through vibration before they exploded, because AJ never mentioned it and it was only on the inside of the tire.
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
The way I've understood it, you have to bring the tire slowly up to temp (but not beyond) and then let it sit a minimum of 24 hours or its all for nothing. Kind of like bedding pads.
I used to do it but it's just not worth the wasted heat cycle on the tires and the complexity of tire management with multiple sets of tires/wheels and the track time used to run a couple laps and pull in at a track day.
Now next year I may do just that and have one set used for qualifying only and another set for racing, but for track days I just don't bother anymore.
 
4,651
5,258
It's funny, if you read the tech info on Pirellis and Michelins they tell you to never drop or bounce a tire when it's under 45 degrees. One of the Porsches came in air freight on Michelin rains and they advised to discard the tires because of the temps they were exposed to.
Of course, I've also noticed the manufacturers rolling them out of the semi onto the pavement when it was under 45 so.....
 
5,320
6,059
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
It's funny, if you read the tech info on Pirellis and Michelins they tell you to never drop or bounce a tire when it's under 45 degrees. One of the Porsches came in air freight on Michelin rains and they advised to discard the tires because of the temps they were exposed to.
Of course, I've also noticed the manufacturers rolling them out of the semi onto the pavement when it was under 45 so.....
Hoosier says that too.
 

Dave_W

Cones - not just for ice cream
568
660
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
The stickers will always be faster BUT will not last as long as the tires that have been cycled....basically name your poison, speed or longevity.
That's always what I've heard as well. Put me in the frugal camp.

I've heat-cycled tires by doing figure-8s in the high school parking lot at night. Like everyone has said, easy at first, then gradually more aggressive. Avoid sliding, and I try to keep the noise to the "tearing fabric" sound rather than squealing. Took a few minutes and didn't have a tire pyrometer to "stick" the tread to get a definitive read, but hand on the tire felt pretty warm to hot. Back in the FWD days, since the rear tires are just along for the ride, I'd put the race tires on front and street tires on the rear, run the figure-8s, go home, swap the other pair of race tires on the front, and do it again.
 

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