granracing

Last time I tried to heat cycle my tires, it doesn't seem like I got the tires hot enough. I went to a very remote area and did some minor weaving back and forth. On a few of the minor curves, I made sure to use the tires. After doing this for a little while, I felt the tires and they were definately warm but not hot enough. I thought about taking the car on the highway, but know it wouldn't get the tires hot.

I can not think of a place where I can do figure eights safely or without getting in trouble. I also don't want to use a track day to do this - would really like to do it on non-racing time. Even if I did go that route, I will not have a HPDE between the time that I mount the tires and my race.

How do you do it? (Besides having another company such as tire rack do it for you.) The place I buy my tires does not offer this service, but they do the best shaving job I've seen. Any suggestions?

Thanks,
Dave

Catch 22

Run them for practice on Saturday morning them take them off until Sunday.

Easy. You just need at least 2 sets of wheels.

granracing

Practice and qualifying on are on the same day. No racing on Sundays at Lime Rock Park in CT.

I have two sets of wheels - rain and dry. Can't afford three nor would I want to lug them all around.

travis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Catch 22 &raquo;</TD></TR><TR><TD CLASS="quote">Run them for practice on Saturday morning them take them off until Sunday.

Easy. You just need at least 2 sets of wheels.</TD></TR></TABLE>

Easy, but this assumes that you already have a heat cycled set of tires for the qualifying/race on Saturday (meaning you planned ahead at a previous event).

Unfortunately, I don't think you will safely be able to bring the tires up to temp on the street. Even on the highway, it's not the speed that creates the heat but rather the friction. For that, you need to be slipping (bad idea on the highway).

ZygSpeed

I'm not sure you actually need to get the tires hot, since Tire rack says they heat cycle tires by running them on a drum type roller for 15-20 min.

http://www.tirerack.com/tires/...h.jsp

They used to recommend 1/2 hr at highway speeds as a substitute for their heat cycling process, but an important aspect is to let the tires rest afterwards for a day or two. Ed

SM 30 Hatch

I went to a remote place and did a figure eight for about 10 mins.. got the fronts scrubbed real well, but the rears still couldn't get.. not enough weight in the back I guess...

I agree.. the key is to let the tires sit for at least 24 hours after heat cycling.

92TypeR

For my DIY heat cycle I drove from my house to the highway (~15 min), then about 25 minutes on the highway at about 65mph, then about 10 minutes off the highway to the track.

From what I've read and been told, the whole point is to slowly bring the temps up, hold them for a while, then slowly bring them back down.

rpr

I know I'll probably get flamed for this, but just say, hypothetically speaking, I have an old electric oven in my garage, and I wanted to heat cycle some tires, could I use that? Set it at say 150C, bake them for 20 minutes, then shut it off and let them cool down?

No, it's not an April Fools post, I really would like to know. It sounds dumb and smart at the same time...

ZygSpeed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rpr &raquo;</TD></TR><TR><TD CLASS="quote">I know I'll probably get flamed for this, ... </TD></TR></TABLE>

From the above Tire Rack link:

Running new tires through an easy heat cycle first, and allowing them to relax allows the rubber bonds to relink in a more uniform manner than they were originally manufactured. It actually makes them more consistent in strength and more resistant to loosing their strength the next time they are used. An important heat cycling step is that after being brought up to temperature, the tires require a minimum of 24 to 48 hours to relax and reform the bonds between their rubber molecules

It is very important to note that this allows heat to be generated as a result of deflecting (stretching) the tire within its normal operating range. There is no "artificial" heat added (no oven, no forced air, etc). Then they receive the stamp showing they are Tire Rack heat cycled.

CRX Lee

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">I'm not sure you actually need to get the tires hot, since Tire rack says they heat cycle tires by running them on a drum type roller for 15-20 min.
</TD></TR></TABLE>

I have been to the Tire Rack and seen their heat cycling machines in operation and they do get quite hot, hot enough that you would rather not want to lay the open palm of your hand on the tread face for too long. And indeed it is heat generated from within the tire itself and not from external heat.

Catch 22

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by travis &raquo;</TD></TR><TR><TD CLASS="quote">

Easy, but this assumes that you already have a heat cycled set of tires for the qualifying/race on Saturday (meaning you planned ahead at a previous event).
</TD></TR></TABLE>

Yes, depending upon race schedules you do need to plan ahead.

SJR

and the very first time you do it... buy a set of used, already heat cycled tires to race on. Got to start that cycle some how.

Crosser

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SM 30 Hatch &raquo;</TD></TR><TR><TD CLASS="quote">I went to a remote place and did a figure eight for about 10 mins.. got the fronts scrubbed real well, but the rears still couldn't get.. not enough weight in the back I guess...

I agree.. the key is to let the tires sit for at least 24 hours after heat cycling.</TD></TR></TABLE>

That is simple, put the tires you want heat cycled on the front of the car only. So you put two new tires on the front, go out heat cycle them. Come back removed them and put the second two on the front and go out and heat cycle them the same way. Obviously you need to take care having different tires on the car front and back.

descartesfool

Travis, I think you are incorrect on that. It is not sliding or slipping that puts the heat into the tires, it is load. The harder you drive, the more load you put into the tire (from the g forces) and the more that works the carcass and distorts the contact patch, which heats the tire's rubber molecules.

Here is some info from guys who make race tires in England for F3000 and other series. Comments about front tires here apply to rear wheel drive formula cars, and not to FWD Hondas, but the concepts are the same

"Use of Racing Tyres
For most purposes, racing tyres will benefit from an appropriate 'Scrubbing in' procedure. This provides the best combination of performance and longevity under race conditions.

There are several difficulties that arise when using racing tyres if they are not scrubbed in prior to use. The most common is "Cold Graining", where the layer of the tread compound in contact with the track, fails in shear with the layer below. The result is a very visible low frequency, high amplitude rippling effect. This is more common with new tyres particularly when used in wet, damp or greasy conditions.

Cooper-Avon Racing Tyres recommend that a standard scrubbing in procedure be used whenever possible (conditions and regulations allowing). This consists of subjecting the tyres through one gentle heat cycle, gradually loading them up whilst avoiding drifting the car. This should take about three to four laps of a circuit where the lap time is in the region of 60 to 100 seconds. The last lap should only be about 80% race speed. If possible, scrub in at least one new set of tyres during free practice, and put these aside for the race. In this way you will know that they have been balanced correctly, and have no slow punctures etc. Getting this done early is important as the qualifying session may become wet or be red flagged, which could force the use of new tyres in a race.

When regulations or circumstances do not allow the above procedure to be carried out, then the following should be borne in mind: -

Graining of the loaded front tyre can be avoided if it is ensured that they are fully up to temperature before pushing hard.
It is relatively easy to generate temperature in the driving tyres as they are transmitting power most of the time. The front tyres, however, will need to be given more time and be loaded up progressively before they will be 'In' fully. It should be noted that it is the loading of tyres that introduces the significant heat, not sliding or wheelspinning.
For qualifying, the best results have been shown to have been achieved when the front and rear tyre temperatures are the same when measured at the base of the tread. If pushed too early, the rear will come in before the front causing understeer, and taken to the extreme, cold graining as detailed above.
It is quite possible to get the rear tyres to go off before the front tyres come in, which will lead to a car that is never balanced, making set-up and qualifying very difficult.
Thus to get the best from a set of scrubbed tyres, look after the rear tyres by not using full power out of corners, and instead work the front tyres progressively without inducing large amounts of understeer. When the fronts are fully up to temperature, go for a time (really hooked up lap). Push hard for 2 to 3 laps, and then back off the pace for a lap to allow the tyres to recover, and to get some clear track. Repeat this procedure for the best results.

It should be noted that there is always going to be a slight performance peak from new tyres, but it will only be possible to take advantage of this if the car is balanced on its tyres. A correctly scrubbed in set of tyres will always give more consistent performance over its lifetime than a set that has been used hard from new, even if it hasn't grained."

I would get my info direct from the tire manufacturers about heat cycling. As far a I know, the Tire Rack is not a manufacturer, and I have tried many times to get technical info from them about tire setup, but their advice has been all but useless. I have completely given up on those guys! When BFG Goodrich were promoting their track tires, the R1, one of their engineers had written a very good piece on heat cycling. I have a paper copy but it is no longer on their web site. It said more or less the same thing as the Avon article.

rpr

Thanks guys, I was sure it wasn't the right way to do it, I just didn't know why. Now I do!