Tire heat cycle

[SNKBYT]

What temperature does a tire have to reach before it has to be countered/considered a HEAT CYCLE? Does driving an hour to the track count as a heat cycle. I have Pilot Sport cups that have 4/32 of tread left. Have used them for 4 track sessions. Buit have driven them 2000 miles maybe. The last time I tracked them they,got greasy after 4-5 laps. This was also the hardest I ever pushed my 09 ACR. Are my tires used up as far as track perforamce goes?

 

[Allan]

About 180 degrees. I ran through 2 sets of Sport Cups last season. 4/32 of tread is still pretty much new. I think you will run out of tread before the tires 'heat-cycle out'. .......just to let you know, these tires cord right away as soon as the tread is gone. I mean, like right away!.......don't ask how I know.

 

[SNKBYT]

When/how do you know when the tires have become hard or heat cycled? I heard that when they become (greasy) loss of traction when hot that they were used up? The last time I ran them,after 4-5 laps they car got very loose in the corners. Never experienced that before. I felt I was driving the car harder than I ever had previously. Tires are 3 years old. Do tires reach heat clcle temperature from driving on the street?

 

[Timnineside]

On the topic of track, do you guys have a track alignment? I have a local shop that does a lot of work for me. Thinking about throwing eibachs on the car over winter. Any suggestions or recommendations I can have to let the guys know where to put the measurements?

08 SRT Coupe.

Thanks!

-Tim

 

[JGarrett]

Snkbyt your tires are probably well past done. Allan the tread can look brand new but the tire is toast. In all honesty one typical DE weekend of eight sessions is really about it, and maybe not that. Depending on setup, braking, surface conditions, it is possible to go through tires in a day or only a couple of heat cycles. I was 3-4 seconds a lap faster on the new tires after one weekend. Huge! For a newbie you might go 2 DEs loafing the car around. I see folks all the time say look I have tread I'm fine. Then spend an entire session getting the tire up to temp because they are so hard and holding up the Miatas. Conversely, I see the folks who have cord showing and say they will flip them to run just one more session. Both are wrong, unsafe, and not nearly as fun as new shoes. I've seen plenty of cars in the wall due to bad tire decisions over the years. Really is one 30 min session worth you're butt? It's an expensive, insanely fun hobby; plan on tires to last a weekend or maybe part of two max at a typical DE. To save money in the long run buy another set of wheels to mount your track tires and drive to the track on the street set. The next step is the tow vehicle to drive the dedicated track car to the track. Remember street tires are not really great track tires. All the best. Drive fast but safe!
Cheers,
Jim

 

[Allan]

Tim, I have track alignment. -amazing difference.
Jim, I was getting 4 days out of a set, 4/5 sessions per day. Tires progressively lost full performance, but still felt OK all the way to the cords. For HPDE as long as you adjust to it, I think it's alright. For competition, that would be different.
SNKBYT, I don't think you can get tires to full temp on the street without getting attention from the cops.

 

[SNKBYT]

So back to my original question. Are my tires used up/junk for the track? What are the telltale signs?

 

[hou99gts]

So back to my original question. Are my tires used up/junk for the track? What are the telltale signs?

When you start sliding around in places you didn't used to under similar track conditions, your tires are done regardless of tread remaining. You will know it when it happens, there will be a big difference in grip level, especially in the rear. When you get a new set of tires on you will notice a big improvement in grip. Mileage, number of track days, street driving, etc. does not matter, you will notice a difference with the cups when they are done.

 

[bluesrt]

usually when i start to slide around, i search for new lines on the track to find grip, its there,you have to find it...

 

[ACR steve]

With our cars there is one fast linethrough a turn , anything else just feels fast in your head.

You can run your cups if there heat cycled out . Just understand they willslide more and may not brake as well. It can actually help you be a smoother driver. The real issue iswhen you have miss matched cycle tires at different corners. This creates avery difficult to predict situation

 

[bluesrt]

there are a few differant fast lines in turns, you have to find them,and sometimes that fast line goes away,you have to find another one

 

[ACR steve]

We have a difference of opinion on that. Oval racing has groves that develop due to changes that happen over a course of a race ( Track temps, tire temps, suspension temps, tire wear Etc Etc) whether it be car or track changes However on a road course in a HPDE type atmospherethe line is the line. I will agree that sometimes you will adjust your turn inbased on what the car is doing at the entrance, middle or exiting a turn .(oversteering or under steering) . But when you say fast line I can assure you afterracing everything from open wheel , showroom stock and Nascar (on a roadcourses) that there is truly one “ fast line”. My competitors may feel like youand think they knew a faster line but after winning around 15 championships in20 years I would beg to diff. and every telemetry session I have driven would not support multiple lines that would equate the fastest lap time that can be attained.

Maybe a better way to say it is that youadjust your line based on the cars responses during that session. It can stillbe fast but not the fastest.

Don’t take this as me being a picky ass it’s just that I teach a lot of instruction and private coaching and the whole idea of driving safely and fast on a track is learning the proper line on the track. The next step is to take the line and develop your ability to carry the maximum speed atainable for that given segment.

"The perfect line will always be there however the perfect lap will never be "-(My quote) - meaning its easier to find the line but much harder to do everything else perfectly

 

[TrackAire]

We have a difference of opinion on that. Oval racing has groves that develop due to changes that happen over a course of a race ( Track temps, tire temps, suspension temps, tire wear Etc Etc) whether it be car or track changes However on a road course in a HPDE type atmospherethe line is the line. I will agree that sometimes you will adjust your turn inbased on what the car is doing at the entrance, middle or exiting a turn .(oversteering or under steering) . But when you say fast line I can assure you afterracing everything from open wheel , showroom stock and Nascar (on a roadcourses) that there is truly one “ fast line”. My competitors may feel like youand think they knew a faster line but after winning around 15 championships in20 years I would beg to diff. and every telemetry session I have driven would not support multiple lines that would equate the fastest lap time that can be attained.

Maybe a better way to say it is that youadjust your line based on the cars responses during that session. It can stillbe fast but not the fastest.

Don’t take this as me being a picky ass it’s just that I teach a lot of instruction and private coaching and the whole idea of driving safely and fast on a track is learning the proper line on the track. The next step is to take the line and develop your ability to carry the maximum speed atainable for that given segment.

"The perfect line will always be there however the perfect lap will never be "-(My quote) - meaning its easier to find the line but much harder to do everything else perfectly

So, you're telling me that you can't break the laws of physics....damn, back to the drawing board

I know that when I went through driving school, I found that being off line by the width of one tire (not even 12") made a big difference in lap times and overall average mph.

Cheers,
George