R Compounds for the track - size & wheel
- Thread starter CL65 Captain
- Start date
I know. No problem, it's all good. (Two currently common American idioms!)
Why go with the 195/50/16? They also have a 225/45/16 that has a outside diameter of 23.8 872 revs (vs 23.6 oem 879). For the track it would seem like the 225 would give a much bigger contact patch.
When you switch to hoosiers (which you should not drive on the street at all) do NOT go by the numbers, instead get their specs and go by measured specs, ie. sidewall height, width, etc. their specs don't match street tires and I know guys who have wasted the money on a full set that don't fit!
The difference between contact patches on tires of "a bit bigger" and normal is negligible, its more about how the tire deforms (before you start slamming at that statement do two things 1) talk to a race engineer, 2) think about how a wider tire can accept more slip angle because the tread doesn't "twist" as much)
Now, if you're complaining about oversteer, thinner fronts could be part of a solution (or too wide fronts could be part of the problem) but so could be bad breaking techniques!
I run Yoko A005 Hard slicks, 240/610/17 front and 260/640/17 rear. But I have no more splash guards to prevent rubbing.
Agree with Red about the size of contact patches with different sizes of tire.
I think about it this way. The size of the contact patch is directly affected by tire pressure. If you have 1 million psi in there, you will get extremely little contact because the tire will stay perfectly round and will not deform. If you have 2psi in the tire, you will have a very large contact patch as the tire deforms under the mass of the car. At the same tire pressures, different sizes of tires wont have a different contact patch size.
That said, I moved from 205 (RA1) to a 235 (RA1) front and definately notice the improved ability to rotate the car. I didnt realize it, but those 205s (275 rear) were understeering. Logically I expected it, but I did not perceive it until I moved to the bigger tire up front.
I think about it this way. The size of the contact patch is directly affected by tire pressure. If you have 1 million psi in there, you will get extremely little contact because the tire will stay perfectly round and will not deform. If you have 2psi in the tire, you will have a very large contact patch as the tire deforms under the mass of the car. At the same tire pressures, different sizes of tires wont have a different contact patch size.
That said, I moved from 205 (RA1) to a 235 (RA1) front and definately notice the improved ability to rotate the car. I didnt realize it, but those 205s (275 rear) were understeering. Logically I expected it, but I did not perceive it until I moved to the bigger tire up front.
