N2 Wishlist -Thanks Jim!

First off I'd like to express my thanks to Jim Sokoloff for all his efforts and patience in trying to answer all the questions and opinions posted to this newsgroup. I do have one wish that I don't think I've seen posted before, so forgive me if this has been answered already. I really miss the HOT tire pressure info that was in N1. I always used that in conjunction with the tire temps to adjust my setups, just as we do with our real race car. I know everybody has discussed the affects of the "spring rate" of tires, so it seems we are missing some valuable info about the way the tires blow up under stress. Perhaps with the radial nitrogen filled tires this really is'nt a factor as it is with bias ply tires filled with air. But if the pressures are increased with heat, I'd like to know how much blow up is happening so I can change the shocks or weight to compensate. |=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=| | | |=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|=|

If you go out and drive some laps in practice you can get the current hot readings of the tires - just like real drivers do. I think this model is more realistic. /THansen

Dried nitrogen obeys the ideal gas law even better than plain old air. (Since air has water vapor, which is somewhat non-linear) Chemistry 102: (Ideal Gas Law) PV=nRT P = pressure V = volume n = amount of gas (in mass or mass equivalent units) R = ideal gas law constant T = temperature (on an absolute temperature scale) Since n and T are perfectly constant (and V is almost constant), you can generalize the pressure to be completely linear with temperature. (remember to add 483 degrees to the displayed Farenheit temps to convert to Rankin to use in the above formula.) (Of course, after that explanation, it occurs to me that it's obviously easier if we would just calculate it and display it for you, which we don't currently do... :-) ) ---Jim Sokoloff, Papyrus

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>Dried nitrogen obeys the ideal gas law even better than plain old air. >(Since air has water vapor, which is somewhat non-linear) >Chemistry 102: (Ideal Gas Law) >PV=nRT >P = pressure >V = volume >n = amount of gas (in mass or mass equivalent units) >R = ideal gas law constant >T = temperature (on an absolute temperature scale) >Since n and T are perfectly constant (and V is almost constant), you >can generalize the pressure to be completely linear with temperature. >(remember to add 483 degrees to the displayed Farenheit temps to >convert to Rankin to use in the above formula.) >(Of course, after that explanation, it occurs to me that it's >obviously easier if we would just calculate it and display it for you, >which we don't currently do... :-) )

But the calculations in the pits are an estimate, no? Since you don't really know what the actual tire temps are going to be once you get the car on the track. You really need a tire man who can take the on-track temps and make pressure adjustments based on what actually happened. A suggestion for NASCAR 3: I'd like to be able to "examine" the tires after a pit stop, especially during practice sessions, so that I can see if I have a camber problem. Dave Sparks IWCCCARS Project: http://www.theuspits.com/iwcccars Late Night League: http://www.sequoia-dev.com/Hawaii/latenite.html Hawaii Handle: davids

I agree with Rich on this one BTW Rich you said you race cars for real? If you do you have a great name for a racer "Rich Wicker takes the checked flag!!" :)

Thanks for the input Tom an Dave , but I don't think you understood my original post. I was asking about the hot tire PRESSURE not the temperature. If the pressure increases then the spring rate is also increased.

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>>Dried nitrogen obeys the ideal gas law even better than plain old air. >>(Since air has water vapor, which is somewhat non-linear) >>Chemistry 102: (Ideal Gas Law) >>PV=nRT >>P = pressure >>V = volume >>n = amount of gas (in mass or mass equivalent units) >>R = ideal gas law constant >>T = temperature (on an absolute temperature scale) >>Since n and T are perfectly constant (and V is almost constant), you >>can generalize the pressure to be completely linear with temperature. >>(remember to add 483 degrees to the displayed Farenheit temps to >>convert to Rankin to use in the above formula.) >>(Of course, after that explanation, it occurs to me that it's >>obviously easier if we would just calculate it and display it for you, >>which we don't currently do... :-) ) >But the calculations in the pits are an estimate, no? Since you don't >really know what the actual tire temps are going to be once you get the car >on the track. You really need a tire man who can take the on-track temps >and make pressure adjustments based on what actually happened. >A suggestion for NASCAR 3: I'd like to be able to "examine" the tires after >a pit stop, especially during practice sessions, so that I can see if I >have a camber problem. >Dave Sparks >IWCCCARS Project: http://www.theuspits.com/iwcccars >Late Night League: http://www.sequoia-dev.com/Hawaii/latenite.html >Hawaii Handle: davids

============================= Rich Wicker =============================

I realized after the last message that we just check pressures with a tire gauge in the "real" world. I would just like to see the old feature put back in instead of frying my calculator after every run <grin> Rich >(Of course, after that explanation, it occurs to me that it's >obviously easier if we would just calculate it and display it for you, >which we don't currently do... :-) ) >---Jim Sokoloff, Papyrus ============================= Rich Wicker Remove "SpamFree-" to respond =============================