21 replies to this topic

[Speedsterp]

I was just about to order some Toyo RR's along with TR Motorsports wheels C1M and noticed they have option for heat cycling.  I am very new to SM 6 HPDE days.  I have been purchasing take offs and decided to try out a new set.  Is having Tire Rack heat cycle something that is worth doing.  I have read a number of posts about proper break in on tires and they 24 hour post run seems common. Is that simply for the 1/10ths of seconds or does it impact into the 1-2 second range.

 

 

[Caveman-kwebb99]

the heat cycle at the tire dealer is a little better then not doing at all, to me personally not worth.

 

Best result is heat cycle and put away for a week or two or longer then run again afterwards.  This will make the tire last the longest with the slowest fall off of times from HC to HC.

 

Most of us are only running the SM6 a max of 4 HC competitively, so we dont care that much about proper break in.  We qaul on stickers and then race on another set of stickers or on 1 HC tires, and turn that tire into a practice set after the 4th HC.  

 

As we have all said previously every track likes something different.  Some tracks like Mid Ohio like a hardened up old tire where other tracks Like a new tire. It all depends what your going to do with the tires and where your going to run them, as well as what your personal goals are.

 

But IIMO i would not get a tire Hcycled at the tire dealer, that HC is the tires fastest period! so why pay money to lose the fastest HC???

[Johnny D]

So just so we're clear...

RR's are for NASA SM.

SM6 and SM7 are for SCCA SM.

Doesn't matter what tire for HPDE.

 

RR's don't need HC.

SM6-7 should, to make them last.

 

Have I got all theat straight ??

J~

[Johnny D]

Play book for those playing at home.

 

RR          tire by Toyo

SM6-7    tire by Hoosier.

HC         Heat cycle

HPDE    High performance driving experience

MX5      Car by Mazda

SM        Spec Miata Class and type of race car.

 

J~

[LarryKing]

What does S&M stand for?

 

For us po (poor) folk that have to try and get 10-12 HC (heat cycles) out of our HoHos (Hoosier SM6) I do notice a distinct increase (more) in longevity (midpack) when I buy the pre-heat-cycled tires (Phil's Tires)

 

NASA - National Aeronautics and Space Administration

[ChrisA]

For us po (poor) folk that have to try and get 10-12 HC (heat cycles) out of our HoHos (Hoosier SM6)

Which is occurs in essentially one 2-3 day Race or HPDE event weekend.

[Johnny D]

What does S&M stand for?

 

 

         

 

http://www.youtube.c...h?v=5TX9KuXD8dI

[Stix37867]

Since we are defining terms, what is considered a heat cycle? Whenever the tire is heated past ambient temperatures? Whenever brought to "race" temperatures? Somewhere in between perhaps?

When does the heat cycle end? Once is cools to ambient? Near ambient? Anything below "race" temperatures?

Maybe it's time oriented. Would letting the tire sit for a hour, then reheated be considered a heat cycle? Half hour? 10 minutes? Did the full course caution at the Runoffs put a heat cycle on everyone's tires?

And lastly, what is "race" temperature?


Sorry...everyone was doing it!

[Johnny D]

Many tire manufacturers use very aggressive tread compounds for the Track & Competition DOT-legal tires they’ve developed for autocrossing, track days and road racing. And just like other high performance parts, these tires will provide more consistent performance and last longer if they are properly broken in.

The first time Track & Competition DOT tires go into service is very important. All tires deflect under load and their tread rubber compounds repeatedly stretch and relax as they roll into and out of contact with the road. This stretching breaks some of the weaker bonds between the tread rubber molecules, generating heat. If new Track & Competition DOT tires are initially run too aggressively, too hot or too long, some of the stronger bonds will also be broken which reduces tire grip and wear.

Putting new Track & Competition DOT tires through an easy initial heat cycle and then not running them for a minimum of 24 hours allows the rubber bonds to relink in a more uniform manner than they were originally manufactured. Heat cycling actually makes Track & Competition DOT tread compounds more consistent in strength and more resistant to losing their strength the next time they are used.

While it’s important to heat cycle tires, how it’s done isn’t as important.

On the Track
Heat cycling can be done by installing tires on the car and running 10 to 15 minutes on a racetrack. Start with easy laps, and build up speed as the session continues. End up running 5-10 seconds off your normal pace and be careful not to spike the tire temperatures by spinning, sliding or locking the tires.

An important step in tire heat cycling is that after being brought up to temperature, the tires require a minimum of 24 hours to relax and relink the bonds between the rubber molecules. Drivers attempting to heat cycle tires in the morning for use a few hours later in the afternoon will not experience any benefits from the morning attempt at heat cycling. Heat cycling tires on Saturday means not using them again until the same time on Sunday.

By Tire Rack
The heat cycling service begins by mounting the tire on an appropriate-width wheel and inflating it to the desired pressure. It is then placed in our heat cycling machine which has three rollers positioned at the corners of a triangle. The tread flexes where it comes into contact with each of the rollers, stretching the rubber compound enough to progressively bring it up to temperature all the way around the tire and across the tread. There is no artificial heat added by an oven, forced air or heat lamp.

The tread temperature is monitored with a pyrometer to confirm when the tire has reached the desired 170-180° F temperature. The tire is then dismounted and stamped as Tire Rack heat cycled. Since the minimum 24-hour waiting period typically occurs while the tires are in transit, the tires are ready to use when they arrive!

The only thing our heat cycling service doesn’t do is scuff in the tires.

Choices
While both ways will get the job done, many driving enthusiasts have chosen Tire Rack’s heat cycling service because it allows them to maximize their time on the track. They don’t have to invest in extra sets of wheels to manage multiple sets of tires, nor dedicate early weekend sessions to heat cycling new tires for the following days.

We’ve compared tire heat cycling done on our test track and in our heat-cycling machine. Measuring the tread temperatures with a tire pyrometer has confirmed we can’t quite duplicate the heat cycling machine’s controlled process with tires mounted on a car. We found on-the-car heat cycling was challenged by different driveline configurations (front-wheel, rear-wheel or all-wheel drive), vehicle weight distributions and competition camber settings that made it difficult to generate even tire temperatures on front and rear axle positions, as well as across the entire tread. Our heat-cycling machine allowed us to achieve appropriate and more consistent temperatures across the tire's tread without causing treadwear.

[Speedsterp]

Appreciate the input! I decided to go with heat cycling on this first set.

Any recommendations for tire pressure on Toyo RR. I ran used Hoosiers SM 6 at 29 left side and 28 on right. This was at Thunderhill my best time was around 2:13. Hoping to attend HPDE at Infinion/Sears Point in a few weeks. First time at Sears Point.

[LarryKing]

 

Which is occurs in essentially one 2-3 day Race or HPDE event weekend.

 

Three weekends if you do it my way. Sat. - qual and race; Sun. - qual and race: 4 heat cycles.

[pat slattery]

What do you guys think about heat cycling tires on a dyno.  Can you get enough temps with this?

[Johnny D]

Appreciate the input! I decided to go with heat cycling on this first set.

Any recommendations for tire pressure on Toyo RR. I ran used Hoosiers SM 6 at 29 left side and 28 on right. This was at Thunderhill my best time was around 2:13. Hoping to attend HPDE at Infinion/Sears Point in a few weeks. First time at Sears Point.

I'd go higher for Sonoma, even higher for TH if those are hot just off track pressures.

If you're doing consistent lap times, play with the pressures and adjust to what works better for you.

Id have the pressures even all around to start.

 

There's a setup guide in the downloads up top. Not sure if you're in full SM trim yet.

Also there's TFB at the top of the hill at Sonoma that can set your car up if needed, cross weight, alignment, also coaching

or if you have an off and screw something up alignment wise.

J~

[LarryKing]

Speedsterp, do you have, or have access to, a pyrometer?

[RussMcB]

<snip>.

 

Most of us are only running the SM6 a max of 4 HC competitively, so we dont care that much about proper break in.  We qaul on stickers and then race on another set of stickers or on 1 HC tires, and turn that tire into a practice set after the 4th HC.  

 

<snip>

Am I reading that right?  "Most" SM racers (at your level) are buying eight new tires for each race?(!)

 

That's really depressing.

 

Club racers shouldn't even need one new set of tires for each race weekend.  Why bother racing on DOT tires?

[marcusmazza]

Speedsterp,

 

Pressures are going to depend. Your driving style, car setup, the track, etc. all play into it. I played with pressures at the begining of the season (@ NJMP), as the RR was a new tire for us. I started out high, dropped 2psi each session, and measured tire temps until I found what I felt was 'ideal'. Using tire temps, the goal is to get a linear temperature profile across the tire. The SMs run a decent amount of camber, so you will find the inside of the tire will run hotter. Usually 10-20 degrees hotter. Depends on the track. Lot's of long straights, you'll see hotter inside temps. Tight track with short straights, you might not see a huge temp difference inside vs. outside. I found 41psi (hot) to work well for me on most tracks. I ran similar pressures with the RA1s, but many people ran lower pressures with those (36-38ish). I assume the 28-29psi numbers you are throwing out are cold? I'm not familiar with Hoosiers. I can't give you cold pressures, since it really varies with outside temp., track conditions, air vs. nitrogen, etc. I run air, and my cold pressures are usually between 30-35 psi.

 

Marc

[Speedsterp]

I should have noted those were cold pressures at 29 and 28 outside temp was around 45 degrees. I was looking into buying a tire pyrometer, but an experienced driver said the SM is pretty well figured out just ask someone like AIM (tire distributor) for numbers for Toyo RR. Think I might pick one up to better understand setting tire pressure and effect. Is there a link someone could post on proper use of pyrometer and what data means.

Any recommended cold starting pressures for RR?

[Speedsterp]

Also is the AccuTech Deluxe pyrometer for $150 work well enough. I understand optimally you take temps ASAP preferably with assistant. I see some $400 units hold all 12 test spots. While not sure but may need to write down all 12 numbers while taking them with AccuTech. It would seem data best closer to actual off track temp, but would all 12 spots cool uniformly. So data is good for inside middle outside to see if pressure is good. What are you learning with more immediate data more accuracy or how hot tires are actually getting.

[Ron Alan]

I should have noted those were cold pressures at 29 and 28 outside temp was around 45 degrees. I was looking into buying a tire pyrometer, but an experienced driver said the SM is pretty well figured out just ask someone like AIM (tire distributor) for numbers for Toyo RR. Think I might pick one up to better understand setting tire pressure and effect. Is there a link someone could post on proper use of pyrometer and what data means.

Any recommended cold starting pressures for RR?

You will find tire pressure preferences all over the board. I will speak to the RR here...and all my numbers are hot pressures.

 

I've seen guys win coming in at 42psi. Ive seen guys win coming in at 32psi. And of course many things in between! So much depends on how you like to drive the car and the type of feedback you like to have. One end of the spectrum may give better grip but less straight line speed...testing and data will tell you this. Tire wear and life will also be affected by pressures. Bottom line is...experiment and see what works for you! I watched a guy go out on 18psi cold on RR and run top 3 I believe in a tough field! YRMV

 

As far as the pyrometer...i've been told(no expert here) as was mentioned above, 10-20 degree swing. Basically, you want to be using the whole tire surface. So between camber and tire pressure you find that combination which gives you pretty equal temps across the tire. If this is incorrect, somebody please correct me!

[chris haldeman]

Am I reading that right? "Most" SM racers (at your level) are buying eight new tires for each race?(!)

That's really depressing.

Club racers shouldn't even need one new set of tires for each race weekend. Why bother racing on DOT tires?

Sadly this is true. Since the switch too Hoosiers myself and anybody wanting too qual and race in the top 15 around here have been using 8 new Hoosiers per weekend :-( as a comparison I have purchased 2 sets if toyo's all year and have 5 race wins thru out 3 race weekends on the same 8 tires