Originally posted by maski
Bigdog> will Take-Off 32 good in asphalt about 50 degrees C? i usually use Sorex 36R.
Maski- I've found there's a split temp there. In other words, a CS27 wil work well in the first half of the Srox 36r temp range, and the CS32 picks up from there.
I would say CS27 up to 120 deg F and the CS32 from there on up. Of course, different tracks will be different. Our track is a little corse compared to say a smooth finish fresh asphalt, so our track requires moving to the next tire compound earlier in the temp range simply because the corse track generates more heat and begins to overheat the tire before the 5 minutes is up.
The best way to tell is to watch for feathering on the contact patch. If it begins to look feathered, then move up a compound and see how they work.
For those racers who aren't sure what is meant by feathering- Feathering looks similar to tiny wrinkles that go the same direction as the outside of the tire. Thy generally occur in the center of the wear pattern and move out from there. Feathering occurs when the compound begins to overheat and get too soft. Those drivers who have a good "feel" of the car when it's on the track will usually notice a slight push as the tire begins to overheat. A very balanced car that doesn't overheat the front tires before the rear will notice the car beginning to "float" to the outside especially in the sweepers.
While we're at it- blistering is the next step of overheating. You can't miss blistereing- It looks as if someone peeled the "skin" off part of the contact patch of the tire. Blistering is exactly what it says- a blister or really hot spot (area) forms on the tires' surface and literally peels off. It won't come off in a big chunk, but there will be a noticable difference between the blistered area and the nonblistered area as opposed to a feathered tire where there isn't really any area of the contact patch missing, it just has that fine wrinkly look.
I should note that driving has a lot to do with heat generation in a tire. If you're running the "perfect" compound for your temperature and track which is the softest possible compound you can run without overheating or losing traction before the end of the run, you can actually overheat the tire with driving style where another guy might not overheat his (same) tires. This happens especially when you "overdrive" the car. Pitching the car into turns is one very serious example of overdriving the car. Quick direction changes and turning the steering wheel further than the car is actually turning are two more examples. Most of you have read the information on tire traction and the adhesion circle which dictates the most traction a given rubber tire can generate. Any time you surpass that circle, you force excessive heat generation. So if you have never understood why the "fast" guys preach smooth driving, gradual corner transitioning and "slower is faster", now you know a huge part of it.
One last thing- I'm certainly not a pro or sponsored driver, so if anyone who has more knowledge of these aspects of racing wants to add or correct me, please feel welcome. I'm merely trying to help those who want to help themselves....