Conserving your tires during a race?

[JimLill]

Originally Posted by Stack

Man what I wouldn't give to see video of this!!

but even the greats..........

http://www.youtube.com/watch?v=ZgItEAtm79A

[Magnus]

Originally Posted by bbailey

Have your car set up correctly to begin with.

+256879!

Don't know what car you drive, but there can be a major difference in setup depending on if you're doing qualifying laps and endurance laps.

Run the car as light as you can. Weight is your enemy.

High Camber and Toe angles are both tire killers in this case. Camber can somewhat (not much) be compensated with Caster.

Avoid over heating your tires.

Avoid aggressive turn in and out from corners. Make sure to use the width of the track even if it makes you a little bit slower at some sections.

Slow breaking might be tempting, but odds are you'll burn out your brakes by dragging them.

GL

[emilio.battistini]

You should try to adjust the hot pressure to the target suggested by the manufacturer or to your personal experience. Try doing more than 5 (depending on the track length) timed laps in a race-like driving style, stop, check the pressure and adjust it to the target. Repeat the procedure at least once. Note down the measurements and the changes you made. Then you can calculate how to adjust the cold pressure before the start of the race to achieve the desired hot pressure. Remember, when doing the calculation, that you are actually adjusting hot pressures, but you will be setting cold pressures, reduce the adjustments in the cold/hot pressure ratio. You can also let the tyres you used in testing cool down for some hours (better one night), then measure the cold pressure.

Have fun, bye.

Emilio

[Eric]

Emilio, Welcome to the Board!!

Good to add to the European contingent! If you get some time, give us a run-down of where you track and what you track with. I'm curious to see what kind of tracks you run there in Italy.

[billy]

Emilio you are bang on. John and I did exactly what you are suggesting at the last race and it worked well. Bleeding hot tires out in the last session to factory optimals and then checking the cold pressures the following morning works very well to see relative tire pressures as well as the difference the afternoons make on tire temps versus the morning.

[Magnus]

A warning on this!

If the cold/hot difference is too big, change compound. Don't start racing on too cold tires. Even if you get one or two warm-up laps before start. You can severely damage your tires and get an accident if you are running at too low pressure. I strongly recommend adjusting tire pressure when pitting for driver change (or adding fuel if it's not at safe zone).

[billy]

MAgnus has a good point. When I went to Tremblant last year, I saw people with GT3s running Pilot Cups are too low a pressure and the bead was heating up, because it was slipping against the rim, to the point it would slip and the tire deflated. The cups are about 25/28psi cold and 31 or so hot but they were venturing below those levels...

[bbailey]

You can always use nitrogen instead of normal air. Your pressures will only change a few pounds maximum. Maybe the trackpedia group can buy and share a tank?

[emilio.battistini]

Originally Posted by Eric

Emilio, Welcome to the Board!!

Good to add to the European contingent! If you get some time, give us a run-down of where you track and what you track with. I'm curious to see what kind of tracks you run there in Italy.

Hello Eric, and all the guys,

I am a race engineer, working for Maserati. I was engineering an MC12 in the FIA GT international championship the last 3 years. Most of the tracks are in Europe, some in Asia. Never been in USA, although some of my colleagues were in the ALMS/IMSA in 2005, and in Petit le Mans this year.

Bye

[emilio.battistini]

Originally Posted by billy

MAgnus has a good point. When I went to Tremblant last year, I saw people with GT3s running Pilot Cups are too low a pressure and the bead was heating up, because it was slipping against the rim, to the point it would slip and the tire deflated. The cups are about 25/28psi cold and 31 or so hot but they were venturing below those levels...

I agree with Magnus. I forgot to specify that the tyre manufacturer usually suggests a minimum cold tyre pressure, that is the limit to apply when doing the procedure suggested above.
Also, if you run low pressures in the beginning of the race or practice, be careful to avoid running into curbs until the tyre is warm, otherwise you may damage wheels, tyres, or also have sudden leaks which will lead to running with too low pressure for the entire race, with consequent danger of tyre blow.
A benefit could be to pre-heat the tyres with heating cupboard or blankets, if the regulations allow.