Hi experts. When out at our track day on Sunday, sunny and in the 80s, we had some new RE-11s on the JCW. The were not shaved or heat-cycled by the rack, fresh new with maybe 25 miles of road time. The RE-11s just would not stick. Any thoughts? They were on the 09 JCW, stock base suspension and alignment. Per the driver, after a first session heat cycle, they felt good for the first lap and a half, then pretty much became slippery. Any suggestions, should we have them shaved a bit? The did not chunk out or look bad, just would not stick in the corners. Thanks, Don
What air pressure were you running? I used to run some 215/45-17 RE01s on the track and street and I loved them. I had read that the RE11s were only better, but have no direct experience with them.
Air pressure started out at 36 all around. After first run the fronts were up at 48, dropped them all back down to 36. These are the 215/45/17 RE-11s. Maybe we were going the wrong way with our start pressures. Thanks for the quick reply. Don
25 miles on them? No, they should not stick. And unless you cooled them down properly between heat cycles there is a good chance they might never stick. I big part of heat cycling tires is the cool down. If not given enough time for the chemical reaction to take place, the rubber compound will not achieve it's intended molecular structure.
Not an expert, but I did locate this as I didn't know what heat cycling was. FTA: The first time a competition tire is used is the most important. During that run, its tread compound is stretched, some of the weaker bonds between the rubber molecules will be broken (which generates some of the heat). If the tires are initially run too hard or too long, some of the stronger bonds will also be broken which will reduces the tire's grip and wear qualities. 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 losing 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. Tire Tech Information - Competition Tire Heat Cycling Service
Yes, we know about heat cycles, probably did not give these tires enough time between runs. Anyone have direct experience with the RE-11? I imagine we will give these some street time and then see if they can stick to the track. Next step will be to shave them a bit and see what happens. The owner/driver is used to R compound tires that have been pre-heatcycled. It will be interesting on the next track day. More inputs needed, great information by all of you. Thanks Don
So, optimally a new set of track tires should see one easy/mild hot session, then rest for 2 days before normal track use? Has anyone here done that exactly and can feel a significant increase in wear and traction qualities?
I would try running that set on the street for about 500 miles. It should bring them back some. Not going to be 100%, but at least you will get some decent use out of them. Yes, I have. You are not going to see an increase, but instead will get the traction and longevity that the tire was designed for. Otherwise both will be diminished.
I agree with you that the brand new RE-11's could have contributed. It usually takes me about 200-500 miles to break in my Star Specs, which are a similar extreme summer performance street tire, and that's mostly for the mold release goo. Another thing to consider - is the driver accustomed to the MINI? It understeers pretty bad with the stock alignment and suspension setup. Is that what caused the lack of grip, or was it specifically the tires?
This is why most tire retailers will offer to heat cycle the tires for you....it is very important to do.
Do you have any numbers? Cause up to now my first heat cycle has been the first session Saturday morning of a DE weekend. I will scrub off the mold release before the first run if I get time. I haven't noticed any performance decrease based on comparison of similiar tires on similiar cars. But I do tend to go through tires a weekend or two quicker than other folks.
You got me there, I don't have any numbers. I think there are too many variables involved it tire use for anyone to provide hard numbers. Unless you have manufacturer or F1 sized budget. I've yet to use the same tire back to back to even draw a comparison for myself in either case. But I am pretty sure Tire Rack did some testing on that subject, so I tend to take their word for it.
According to the folks at Hoosier Tire, proper heat cycling will increase the longevity of a tire, but have no impact on its performance. My local Hoosier supplier offers mechanical heat cycling, but doesn't recommend it. Just buy more wheels so that you always have a heat-cycled set ready to go. No one said that this track stuff was going to be easy or cheap!
Thanks again, I'm traveling this week, but checking this thread. So how would all of you suggest I save these RE-11s? Don
Don, as you've said before. Drive them around for about 500 miles or so at 70% effort. Throw in some twisities and canyons and they should come back to life.
I think that many have Tire Rack pre heat cycle their tires for them, so they are delivered in track-ready shape.