Track forum general chit chat.

[SAMM3Y]

Originally Posted by M3 Number 86

Drift city! Black flags imminent. :

Dayum!! 😂

[P1zzaboy]

Originally Posted by tsk94

If you're not competing, why bother getting rid of them? Driving on heat cycled out tires (which again I don't think an RS4 is heat cycled out after only 25 heat cycles) is good practice. Doesn't matter if you're a second or two off your PB in an HPDE.

Use em till they cord!

[IMG]

View post on imgur.com

[/IMG]

Because heat cycled out rs4's don't last to the cord like some other tires do. Once some small chunks appear(like the inside thread on the picture) there is not much life in them. There will be large chunks very soon! I usually do 6-8h total track time + commute to the track, for a total of +- 30 separate sessions before they look like this and go to trash.

[derbo]

Originally Posted by P1zzaboy

Because heat cycled out rs4's don't last to the cord like some other tires do. Once some small chunks appear(like the inside thread on the picture) there is not much life in them. There will be large chunks very soon! I usually do 6-8h total track time + commute to the track, for a total of +- 30 separate sessions before they look like this and go to trash.

hmm..

[Bartledoo]

Originally Posted by P1zzaboy

Because heat cycled out rs4's don't last to the cord like some other tires do. Once some small chunks appear(like the inside thread on the picture) there is not much life in them. There will be large chunks very soon! I usually do 6-8h total track time + commute to the track, for a total of +- 30 separate sessions before they look like this and go to trash.

Might be worth trying an intro heat cycle and cure next time, before going ham, to avoid the chunk fest. Everybody who endurance races on these does that to avoid potential chunking.

[slcook54]

Originally Posted by Bartledoo

Might be worth trying an intro heat cycle and cure next time, before going ham, to avoid the chunk fest. Everybody who endurance races on these does that to avoid potential chunking.

Can you expand on what that entails?

[turbo_joe]

Originally Posted by slcook54

Can you expand on what that entails?

Take them out for one session, once they are up to temp come in and take them off the car and let them rest for 24 hours. Can be a pain in the ass even with multiple sets of wheels

[DRLane]

Originally Posted by turbo_joe

Take them out for one session, once they are up to temp come in and take them off the car and let them rest for 24 hours. Can be a pain in the ass even with multiple sets of wheels

What he said ^

It's advised for R comps, DOT slicks, and no DOT slicks. Hopefully an engineer can pipe in, but that first heat cycle, gradual cool and 24 rest allows the rubber molecular bonds to restructure.

It's why you can order them "heat cycled" from the distributor.

[derbo]

Originally Posted by DRLane

What he said ^

It's advised for R comps, DOT slicks, and no DOT slicks. Hopefully an engineer can pipe in, but that first heat cycle, gradual cool and 24 rest allows the rubber molecular bonds to restructure.

It's why you can order them "heat cycled" from the distributor.

http://www.hoosierdirect.com/tire-heat-cycle.html

Heat Cycle Chemistry

Let's look at what a heat cycle is, and what it does to the tire. We will concentrate on the tread compound, but there are similar benefits for the other compounds in the race tire that actually hold everything together. To understand what happens in a heat cycle, let's talk about the molecules that make up the compound. For those of you who don't remember your high school chemistry classes, the molecules that make up polymers are long chains of atoms. To kind of visualize this, think of a bunch of rubber bands. Imagine that they have all been cut with a pair of scissors so that they are not closed loops anymore. Now throw a bunch of them into a box and shake it up. Those represent the polymer molecules.

In addition to being highly intermingled, these molecules are connected, (or attracted), to each other by a variety of chemical networks. For simplicity, we will refer to all of these networks as chemical bonds. These bonds, (or attractions), are what we are concerned with here. During the manufacturing process, these bonds form in a more or less disorganized way. Some of the bonds are very short and strong. Some of them are very long and weak. The rest of them vary between the two.

Now, when you take that tire and run it, things start to happen. The molecules get stretched and compressed. This first causes the weaker bonds that connect these molecules to break. When the bonds break, heat is generated. As the heat builds and the flexing continues, more bonds break, more heat is generated, stronger bonds break, more heat is generated, and so on... Remember that these bonds are what connect the molecules to each other. They give the compound its strength. When this strength is reduced, the compound can't grip the road surface as well. It rubs off instead of holding together. The result is less grip, more slip on the road surface, more heat generated, and more tread wear.

So then, what happens in a heat cycle that can improve the performance and durability of your brand new tires? Well, actually, the situation described above is the first step in the heat cycle process. You want to break all of those "uneven" bonds. What happens next is where the real magic of alchemy comes into play. After these bonds have broken, and this heat has been generated, and the tires are finally allowed to be set aside and relax, the bonds tend to REFORM! But now they reform in a much more uniform manner! This means that they are more consistent in strength. Therefore, the compound becomes more resistant to losing its strength the next time the tires are run. That doesn't mean that you can't make the tires give up anymore. The bonds will still break if you exceed the limits of the compound, (both mechanical and thermal). But they will be more resistant to it because they are working together now as equals (in parallel), instead of individually (in series). And, given the time to relax again, they will reform again in the same uniform manner. Here is the most important thing to learn, and remember about this process. These bonds MUST be given ENOUGH TIME to do their magical reformation. The tires must be allowed relax for an absolute minimum of 24 hours after that initial heat cycle. If you don't give the tires enough time to reform those bonds though, then you are going out on tires with a weakened compound and their performance will show it. Understanding how this works, and how to use it to your advantage, is important to getting the most from your tires.

That said, I don't think its needed for 200TW tires. I'm also beyond that point even if that was sound for street tires.

[tsk94]

Originally Posted by P1zzaboy

Because heat cycled out rs4's don't last to the cord like some other tires do. Once some small chunks appear(like the inside thread on the picture) there is not much life in them. There will be large chunks very soon! I usually do 6-8h total track time + commute to the track, for a total of +- 30 separate sessions before they look like this and go to trash.

What others have said, and I also wasn't being that serious. Just thought it was a good time to show a set of well used tires from last season of tracking lol.

[tsk94]

Heat cycling can definitely apply to 200tw as well. Put it this way, it can only benefit you, it can't make reduce performance or longevity.

[derbo]

Good discussion people!

I'll probably end up driving there with my street tires as spares and just enjoy the day.

[Bartledoo]

If you a large empty parking lot nearby you can do the heat cycle without wasting track time.

[tsk94]

Originally Posted by Bartledoo

If you a large empty parking lot nearby you can do the heat cycle without wasting track time.

Figure 8's.

Heat cycling can be a pain, so I understand why many people don't do it. Requires you to have 2 sets of track wheels on a single track day.

[M eyedoc]

Originally Posted by tsk94

Figure 8's.

Heat cycling can be a pain, so I understand why many people don't do it. Requires you to have 2 sets of track wheels on a single track day.

I have to admit, I am guilty of wondering if they would fit in the oven at home. Might make it easier than doing it at the track...

[rhyary]

Originally Posted by M eyedoc

I have to admit, I am guilty of wondering if they would fit in the oven at home. Might make it easier than doing it at the track...

I think it needs the friction.
Otherwise a tire warmer can do.

[M eyedoc]

I don't have enough knowledge to give an answer. If so, does Hoosier and Tirerack mount and then dismount the tires before shipping?

[dparm]

LOL I never do the break-in heat cycle my Hoosiers. I usually cord them before they heat cycle out, but they are also huge tires and take a long time to really fall off.

For time trial you probably want to just put on the stickers and send it.

[Bartledoo]

Originally Posted by dparm

LOL I never do the break-in heat cycle my Hoosiers. I usually cord them before they heat cycle out, but they are also huge tires and take a long time to really fall off.

For time trial you probably want to just put on the stickers and send it.

Me neither…but I’m not going to dismiss the efficacy when I’ve seen the difference firsthand.

Time attack tires are only fastest for one lap anyways, so you’re probably not chunking them when you just send n end sesh.

[admranger]

Originally Posted by rhyary

Agreed. RE-71R

4 events is fine. if they don't grip, it does not matter if they are corded or not.

Unless you have something else to try besides going fast. Also, toward the end the wear is not linear. You may find yourself on the cords quicker than you anticipated.

Someone has clearly hacked rhyary account. The correct answer is to run the RS4's on the RR and RF and the RE-71Rs on the LR and LF. Sheesh.

If you can schlep two sets of wheels/tires to the track (drive the to track on the RS4s), then go full send on the RS4s. Explore limits of adhesion at lower speeds if the traction has dropped off but predictability is still there. IF they chunk, then swap for the RE-71Rs.

I ran Toyos RA-1s and then NT01s in the Jurassic period. Fast lap was when they corded. Every time. That was a nice perk as you did not worry about running them to the cords.

[k_mann]

I haven't driven the m2c but this is a pretty sweet deal. Kinda wish i was in the market for a car lol

FS: 2021 BMW M2 Competition - DCT in Hockenheim Silver - Fully Dialed In!!!! https://f87.bimmerpost.com/forums/sh....php?t=1888307

[dparm]

Originally Posted by aututto

I haven't driven the m2c but this is a pretty sweet deal. Kinda wish i was in the market for a car lol

FS: 2021 BMW M2 Competition - DCT in Hockenheim Silver - Fully Dialed In!!!! https://f87.bimmerpost.com/forums/sh....php?t=1888307

Nice spec. I'd definitely want to get some aero on that thing.

[k_mann]

Originally Posted by dparm

Nice spec. I'd definitely want to get some aero on that thing.

That's what I was thinking. A ducted lip and mild wing would make a great dual purpose car.

Do aftermarket brakes or suspension void a warranty?