rec.autos.simulators

Some time last year I asked about real racing tyres, and how the tyre
pressure would influence their running temperature. (I know it's slightly
off topic, but it does apply to some sims where you can adjust this, any
anyway, this is the best place to have a discussion like this, 'cause
there's a lot of knowledge in here).

Anyhow, someone managed to convince me that increasing the tyre pressure
would reduce the tyre temperature.

Since than I have experimented with real kart racing tyres on a kart, and
found the opposite to be true.

The lowest pressure you can get away with, with my kart is about 15psi, any
lower and you risk it coming off. The highest is 60psi as marked on the
tyre. I started at 15 psi, and found that the handling was very heavy, and
not too accurate, as the tyres were very soft.

I then gradually increased the pressure, and found that the tyre was
noticeably hotter when I got to 20psi, and each time, I had more grip.
Obviously, you get to a point where the contact patch starts to reduce in
size, and you get less grip, a hotter middle, and cooler edges.

I just thought I'd share this observation with you all.

R.

More grip though means more heat, so because of the better grip you
might have generated more heat, but not more heat per Newton of grip.
In other words, there are multiple effects, that are pushing/pulling
the tire to warmer & colder. More grip means you'll get better
G-forces, but this means that more energy is involved, so a warmer
tire. Given 2 runs with a 15psi and a 20psi tire, requiring to turn
every corner with the same G-forces, it might be that the 15psi tire
must work harder and get warmer nevertheless. You just might not have
come this far though, as the 20psi is then just faster/better.

Hope this is a bit clear. ;-) I just mean it's difficult to see what
is doing what, as you'll (be able to) drive differently as well with
different tire pressures.

Ruud van Gaal
Free car sim: http://www.racer.nl/
Pencil art  : http://www.marketgraph.nl/gallery/