I was thinking recently about tire pressures at track days and came up with a device.

Basically, my idea is to have a second valve stem that is set to release any pressure above X psi (X = your desired hot track temp). the thought is that before you go out on track you just inflate until the release valve opens (no gauge needed). then as the tires warm up on track they bleed off air so you always hold X psi until they cool down (you'll fill tires again before next session). the device would be 100% mechanical with some sort of adjustment ring / screw

thoughts?

 

Yup... Longacre sells them... You'll have to drill an 1/8" NPT hole in your rims and set the relief pressure. Never used them myself but know of others that do and they like them.

http://www.longacreracing.com/catalo...id=580&catid=9

 

very cool.

 

or you can just fill with nitrogen and not worry about pressure differences

 

good idea though

 

Helium, like you're floating on air!

 

Nitrogen’s coefficient of expansion is .8, as compared to air’s 1.0. So there’s only a 20% difference in the reaction to temperature changes.

 

i'd skip it, because you should be making tire checks more often, based on how the car is doing, conditions around, etc.

I NEVER run the same pressures front to rear (hot), so you'd have to adjust them after every session, every time you flipped the tires, etc.

And last thing i want, is the possibilty to lose a tire out on track, due to an extra hole in my wheels. I've lost one once, and i don't care for it again.