rec.autos.simulators

Some others here may have some more technical answers, but my rule of thumb
with air pressures is to look at the inner/center/outer tread temperatures
of a hot tire.  If the center temp is running cooler than the edges then the
pressure may be a little low, if it is high then the pressure may be a
little high.  This is due to the shape of the tread as pressure is changed.
A little higher pressure also gives you slightly lower rolling resistance,
slightly lower pressure gives a little more grip.

If the inside/outside tread temps are significantly different (a degree or
two can be good depending on your setup) then you have some other setup
issues (camber for instance).

I am no expert, but this seems to work for me pretty well (in simulations at
least).

When you measure tire temps on a kart do you just make a single measurement?
I am not familiar with kart setups at all, but I would assume the same
principals would apply.

-Dave

Generally speaking though, a higher pressure will run cooler and vice versa.
As a non-racing example, remember all of those people last year driving
their Ford Explorers in the US with low tire pressures - this caused heat
build up which caused tire failure.

Strange that this seems to be completely opposite of what you deal with on
your karts.  I know there are some other kart owners here, maybe someone
else can add some comments.

I agree with Damien that the tire model does not appear to be real accurate
in F12001.  I typically turn off tire wear and just work with pressures to
get the best grip - or I suppose you could buy F12002...

-Dave

I agree on F1 2001. My understanding is that the FIAGT-mod had to make
some serious tweaking regarding tyretemps and it didn't get quite
right even then. In the first installment I constantly got like 160
deg. on the fronts in the Porsche no matter what... While I never got
any temp at all in the F1's.

Firstly, a tyre with a higher pressure will have lower rolling
resistance and thus produce less heat, and so run cooler.

Secondly, a tyre which is running cool doesn't increase its
pressure so much over the cold value, and so a higher cold
pressure is needed to reach the same operating pressure.

Not sure if that helps or not... :-)

Jonny

   I used to think that too Richard, but the dang tire modeling is just to
wrong.   If you slide into a corner, then you can almost bet you will be
swapping ends on the next turn.   I too like the idea of saving your tires,
but they have just botched it with 2001.   In the demo of 2002 this appears
to have been fixed.
I got the 'turn off tire wear' from the mod makers, FIA GT at simbin.  and
I've carried that over from the mods to the F1 cars also...(but then I only
drive the F1 cars to make sure the sim is working right...then back to the
Vipers or LMP cars...)  :)
dave henrie

I suppose it is enough to say that what we see in F12001 isn't completely
realistic.

It appears that on karts maybe due to the small tire size, light kart
weight, greater % weight change from the driver, that possibly some of the
standard rules don't apply to the same degree.  You can look at several
resources including Carroll Shelby's Drive to Win book, stuff from Skip
Barber, Rodney Arndt's Nascar 2002 setup guide, even the original GPL Four
Wheel Drift guide and all point to the standard high pressure = less grip
and lower temps and vice versa.  These references cover everything from
street performance radials to nitrogen filled slicks used on Winston Cup and
open wheel cars.  All of the simulators that I have used all seem to follow
these guidelines.

Try the center vs. edges tire temp rule of thumb I mentioned on the PC and
see what happens.  You can also probably get a little more grip on that
inside front tire by playing with the anti roll bars and/or springs (just a
little).  Since the inside front tire isn't working too hard, you are
probably feeling a little understeer as the front end pushes through the
turn.

Also download the F12002 demo and see if it makes a difference.  I haven't
really tried it yet.  Got enough to do with GPL and N2002.

Thanks for the info on the karts, have been considering trying them out
myself sometime.  I have a buddy near Sears Point in California that has won
some regional kart championships and has been tempting me to try it out for
the past year.

-Dave

-----------------------------------------
Dan Belcher
Webmaster,
http://simcrash.fameflame.dk