Originally Posted by xbgs351
Obviously the author isn't well informed.
Agreed! The author is certainly not talking from experience when he says to increase pressures for track days. Hacking the car thru corners and hard braking on track days puts a LOT more heat into the tyres - consequently the internal gas (air or nitrogen) will expand at a greater rate. Running higher pressures means the tyre pressure will EXCEED even the manufacturer's recommended max. Your road going tyre pressure aint gonna cut it on the track - THEY NEED TO BE REDUCED FOR TRACK DAYS!!!! The ambient air temp makes a diff too.
Things that have an impact on tyre pressures:
- weather conditions - air temp, rain, snow!!
- driving conditions - hard corners or straights
- driving style - turn in hard or take the long apex through a corner
- gas used - air or nit
- tyre compound - thermodynamics of the compound
- suspension setup - camber, toe, spring and damper rates etc
- road surface - guage of top coat (country road or hot mix), dirt etc
Bottom line - every car and driver is different and there is NO one pressure that is perfect. You have to play with your pressures in order to find what is right for you and your setup. It takes time but is worth it.
Pressures are certainly a science with lots of variables. They aren't like a "bolt on" where it either works or it doesn't. Its more like the weather, you can try and try to get real close but never exact, sometimes you're not even close. Ultimately, the only way to get accurate results is to use a pyro. Have a look the thread (18" tyre pressures) for some info on pyros and tyre temp.