Proper way to heat cycle Dunlops
Discussion
I figured you guys on the other side of the pond might know the best way to heat cycle Dunlop tires when new. I race at Spring Mountain in Nevada and it is starting to get pretty cold out there now and I could use a few pointers.
On my last set of tires I feel I didn't get enough heat into them and only let them sit over night rather than at least a full 24 hours. I did three laps at 50% on a 1.5 mile track. I just didn't feel like they had as much grip as they should have. Yes it was a bit colder than normal, but it still felt off to me.
Is there any guidance from Dunlop on the recommend scrub in procedure? Any real world advice would be appreciated too.
Should I run the tires witth a few more lbs of air during the scrub in session?
Thanks!
On my last set of tires I feel I didn't get enough heat into them and only let them sit over night rather than at least a full 24 hours. I did three laps at 50% on a 1.5 mile track. I just didn't feel like they had as much grip as they should have. Yes it was a bit colder than normal, but it still felt off to me.
Is there any guidance from Dunlop on the recommend scrub in procedure? Any real world advice would be appreciated too.
Should I run the tires witth a few more lbs of air during the scrub in session?
Thanks!
This took some finding (not on PH!) >
One of the ROC Member Racers wanted to get a feel for how many heat cycles Radical 13" Dunlops can go through from new (he happens to have a PR06, but I don't think that changes things particularly) without losing too much of their performance. He'd noticed that whilst they can still look good to go, they can still be to the point where they only have a considerably reduced grip left.
This is the advice we obtained from a (then and still) Works SR8 Driver which I think you'll find useful; here's his reply >
Just fairly briefly, there’s no fixed answer. Two BIG variables: Of what does a heat cycle comprise and what is meant by “too much” of their performance? Answer maybe also varies according to the make of tyre. If a heat cycle is a 20-odd minute race then I wouldn’t expect them to maintain podium pace for much more than two to three races. If a heat cycle is somewhere below race pace then a lot longer.
Without doubt the single best way to maintain a tyre’s durability and longevity is to put it through a shortish heat cycle - for as long as possible before they are used in “anger”. At a meeting, I’d do 4-5 laps at ¾ race pace and then take them off, leaving them overnight before racing them. I’d tend to use the final trackday session or last part of qualifying the day before so that they could properly ‘cure’ for 12 hours or more. I think this is a good strategy and something I still try to do to this day.
More than anything else, the best (only?) way to get the best out of a tyre is to:
1) Heat-cycle them the day before
2) Use a pyrometer (needle probe type, rather than infra red)
3) Use the pyro readings to adjust pressures especially between front and rear, but also between the two sides of the car
4) Use the pyro reading to adjust cambers more precisely – different tracks require different cambers.
And one more thing.I ALWAYS remove the pick-up from my tyres whenever I can. Heat gun and paint scraper.
1. The action of the heat gun has no heat-cycle effect.
2. Yes it is important to do. Listen to many people and they’ll tell you it’s not. Ask Dunlop and they’ll say it is. Ask me and I’ll say it is, and what’s more important is that if it's a rolling start, as I launch the car at the first bend I want to think “these tyres are the dogs b
ks” not “ahhh, they’ve got all that debris on them so they’re a load of old bks”.
3. No you don’t run the pick-up off in the first couple of laps
Hope the above is of use
One of the ROC Member Racers wanted to get a feel for how many heat cycles Radical 13" Dunlops can go through from new (he happens to have a PR06, but I don't think that changes things particularly) without losing too much of their performance. He'd noticed that whilst they can still look good to go, they can still be to the point where they only have a considerably reduced grip left.
This is the advice we obtained from a (then and still) Works SR8 Driver which I think you'll find useful; here's his reply >
Just fairly briefly, there’s no fixed answer. Two BIG variables: Of what does a heat cycle comprise and what is meant by “too much” of their performance? Answer maybe also varies according to the make of tyre. If a heat cycle is a 20-odd minute race then I wouldn’t expect them to maintain podium pace for much more than two to three races. If a heat cycle is somewhere below race pace then a lot longer.
Without doubt the single best way to maintain a tyre’s durability and longevity is to put it through a shortish heat cycle - for as long as possible before they are used in “anger”. At a meeting, I’d do 4-5 laps at ¾ race pace and then take them off, leaving them overnight before racing them. I’d tend to use the final trackday session or last part of qualifying the day before so that they could properly ‘cure’ for 12 hours or more. I think this is a good strategy and something I still try to do to this day.
More than anything else, the best (only?) way to get the best out of a tyre is to:
1) Heat-cycle them the day before
2) Use a pyrometer (needle probe type, rather than infra red)
3) Use the pyro readings to adjust pressures especially between front and rear, but also between the two sides of the car
4) Use the pyro reading to adjust cambers more precisely – different tracks require different cambers.
And one more thing.I ALWAYS remove the pick-up from my tyres whenever I can. Heat gun and paint scraper.
1. The action of the heat gun has no heat-cycle effect.
2. Yes it is important to do. Listen to many people and they’ll tell you it’s not. Ask Dunlop and they’ll say it is. Ask me and I’ll say it is, and what’s more important is that if it's a rolling start, as I launch the car at the first bend I want to think “these tyres are the dogs b
ks” not “ahhh, they’ve got all that debris on them so they’re a load of old bks”.3. No you don’t run the pick-up off in the first couple of laps
Hope the above is of use
Splitty's post is all good and one I have tried to follow as & when possible.
The only thing I would add is from my experience the tyre scrapping with the aid of heat gun is such a lot of phaff & hard work, I've only done it the once & never again. Even so I'm not known for struggling for pace on the first lap!
The only thing I would add is from my experience the tyre scrapping with the aid of heat gun is such a lot of phaff & hard work, I've only done it the once & never again. Even so I'm not known for struggling for pace on the first lap!
Edited by dsl2 on Sunday 28th November 20:37
Thanks for the info!
I think I am going to invest in a Pyrometer to make sure I dial in this process. I think my issue may not be adjusting my break in process when the weather gets cold.
I did find some interesting reading from the Hoosier FAQ (tctr6_a6.pdf).
Seems like good info for tire break in no matter what tires you use. Note the comment Not “the next day” below, waiting 24 to 48 hours is even better.
From Hoosier FAQ------------------
TIRE bREAk-IN PROCEduRE
Proper break-in will not affect initial performance but will increase the competitive life of the tire.
The procedure can be broken down into phases. 1st phase: The initial run
2nd phase: The length of the time the tire is allowed to “cure”
ThE INITIAL RuN hEAT CYCLE
R6 Roadrace
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 pos- sible 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.
A6 Autocross
For autocrossing, the A6 does not need the same break in procedure as the R6. The A6 needs a minimal scuff-in session before the first autocross run. This “session” can comprise of simply driving around the event site at minimal speeds on the A6 set of tires. By scrubbing off the newness of the tread (no or minimal shininess remaining) prior to your first competitive run, the A6 tires will be more consistent in handling, grip and responsiveness on the first run. If this is not completed, running on un-scuffed A6 tires on your first run may result in the tires not gripping properly, or feeling like they “skate” over the course surface. You are welcome to run 3 - 5 psi higher when scuffing in a new set of A6’s, but be sure to reset them to the correct operating pressures before your first autocross run. As you compile autocross runs on your new A6’s, they should become more consistent in run times.
“Cure” Time
After completing the initial run phase, the length of time the tire is allowed to set is possibly more important. The barest minimum for this process to be beneficial is 24 hours. (Not “the next day”). Any less than this is a waste of time. The best situation would allow a week before using the tire again.
Proper tire management is a difficult process. To accomplish this almost always requires a second set of wheels. The payoff is greatly increased competitive tire life.
Following the recommended break-in procedure will require a lot of planning to make it work. The benefits to doing it right include greatly increased tire life as well as consistent performance and durability under stress. Please make an effort to educate your team on the importance of this. It can save you a lot of money.
TIRE TEmPERATuRE RECOmmENdATIONS
For best performance the expected temperature range will vary from track to track. Generally, optimum traction will be generated when the pit lane temps show 180-200 degrees for the R6 in Roadrace applications, and 110-140 degrees for the A6 in an Autocross application.
Note: Use of static infra-red pyrometers is an inaccurate method to monitor tire temps.
I think I am going to invest in a Pyrometer to make sure I dial in this process. I think my issue may not be adjusting my break in process when the weather gets cold.
I did find some interesting reading from the Hoosier FAQ (tctr6_a6.pdf).
Seems like good info for tire break in no matter what tires you use. Note the comment Not “the next day” below, waiting 24 to 48 hours is even better.
From Hoosier FAQ------------------
TIRE bREAk-IN PROCEduRE
Proper break-in will not affect initial performance but will increase the competitive life of the tire.
The procedure can be broken down into phases. 1st phase: The initial run
2nd phase: The length of the time the tire is allowed to “cure”
ThE INITIAL RuN hEAT CYCLE
R6 Roadrace
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 pos- sible 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.
A6 Autocross
For autocrossing, the A6 does not need the same break in procedure as the R6. The A6 needs a minimal scuff-in session before the first autocross run. This “session” can comprise of simply driving around the event site at minimal speeds on the A6 set of tires. By scrubbing off the newness of the tread (no or minimal shininess remaining) prior to your first competitive run, the A6 tires will be more consistent in handling, grip and responsiveness on the first run. If this is not completed, running on un-scuffed A6 tires on your first run may result in the tires not gripping properly, or feeling like they “skate” over the course surface. You are welcome to run 3 - 5 psi higher when scuffing in a new set of A6’s, but be sure to reset them to the correct operating pressures before your first autocross run. As you compile autocross runs on your new A6’s, they should become more consistent in run times.
“Cure” Time
After completing the initial run phase, the length of time the tire is allowed to set is possibly more important. The barest minimum for this process to be beneficial is 24 hours. (Not “the next day”). Any less than this is a waste of time. The best situation would allow a week before using the tire again.
Proper tire management is a difficult process. To accomplish this almost always requires a second set of wheels. The payoff is greatly increased competitive tire life.
Following the recommended break-in procedure will require a lot of planning to make it work. The benefits to doing it right include greatly increased tire life as well as consistent performance and durability under stress. Please make an effort to educate your team on the importance of this. It can save you a lot of money.
TIRE TEmPERATuRE RECOmmENdATIONS
For best performance the expected temperature range will vary from track to track. Generally, optimum traction will be generated when the pit lane temps show 180-200 degrees for the R6 in Roadrace applications, and 110-140 degrees for the A6 in an Autocross application.
Note: Use of static infra-red pyrometers is an inaccurate method to monitor tire temps.
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