Cold tires question (R-compound)
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Cold tires question (R-compound)
I'm running the Dunlop SP Super Sport race tires now, but I have never push them when cold. The other day I was out testing my new alignment setting by RRE, and took a sharp turn pretty fast (the tires were still cold). The rear steps out with no warning (almost like driving on a wet surface), but I was able to corrected it. So, my question is, do R-compound tires have no grip when they are not up to temp?
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From: South Carolina
Short answer. Yes.
Long answer.
There are many things that go into when a tire grips and doesn't grip. Its compound is one of the biggest. All tires work in a specific temperature range, under that range they do not offer as much grip, and over that range they dont offer as much grip, when tires get hot you hear drivers saying they got "greasy."
A "street tire" might have optimum grip at 110' an Azeni at 120-125' a Hoosier Autocrosser likes 140-150 Toyo Proxy RA1 likes 180-200' and a Goodyear racing slick operates 200-220'. So when you are on an R Compound, you are very far away from its optimum temperature when you leave the driveway/shop and the tires are at 80' (or less if its cold out) So in that case you do want to give consideration to tire warming. The best way to warm tires is simply to ride the brake. Heat builds up in the rotor, hub, then wheel and goes to the tires. Bursts of acceleration and braking also do this, and all in a straight line so you dont spin the car on the cold tires.
Another major factor though is the surface. Early morning roads have dew on them, they are also cold which makes it harder to put heat in the tires, on a track there is often a thin layer of sand onthe track the first session.. if you are doing it on the street. (which I am hoping you are not, but i wont preach now) It always has grit, oil, etc and in the morning will also be cold.
Also, when testing a new setup with big changes, creep up on the limit, that way it doesn't surprise you.
hope that helped,
Jon K
www.seat-time.com
Long answer.
There are many things that go into when a tire grips and doesn't grip. Its compound is one of the biggest. All tires work in a specific temperature range, under that range they do not offer as much grip, and over that range they dont offer as much grip, when tires get hot you hear drivers saying they got "greasy."
A "street tire" might have optimum grip at 110' an Azeni at 120-125' a Hoosier Autocrosser likes 140-150 Toyo Proxy RA1 likes 180-200' and a Goodyear racing slick operates 200-220'. So when you are on an R Compound, you are very far away from its optimum temperature when you leave the driveway/shop and the tires are at 80' (or less if its cold out) So in that case you do want to give consideration to tire warming. The best way to warm tires is simply to ride the brake. Heat builds up in the rotor, hub, then wheel and goes to the tires. Bursts of acceleration and braking also do this, and all in a straight line so you dont spin the car on the cold tires.
Another major factor though is the surface. Early morning roads have dew on them, they are also cold which makes it harder to put heat in the tires, on a track there is often a thin layer of sand onthe track the first session.. if you are doing it on the street. (which I am hoping you are not, but i wont preach now) It always has grit, oil, etc and in the morning will also be cold.
Also, when testing a new setup with big changes, creep up on the limit, that way it doesn't surprise you.
hope that helped,
Jon K
www.seat-time.com
