"Exotic" CFC for inflating tires -

Well, I guess you can learn something new every day.

Just read in R&T that in the new F1 rules for slicks, the fine print says that you can inflate them only with air or nitrogen - no "exotic CFC mixes such as Ferrari and McLaren have done in the past."

What does this mean? I take it that CFC is akin to some grade of Freon - so would just guess that it had some kind of heat transfer purpose - but does it mean they are trying to cool the tires, heat the tires, or what?

Can anybody comment on this?

 

That is a reasonable guess - less pressure buildup with heat. So you think this special CFC may not follow the ideal Boyle's Law?

I was kind of going with the idea of less heat transfer from those outside the wheel front brakes...but who knows?

 

You are where I am at - but still it makes me wonder, WHY WOULD THIS BE BANNED? Surely just the gas in the tires could not be that expensive, compared to what even the lowest team spends on everything else to race.

Please, please, do not tell me that this is "environmental correctness" because the FIA is afraid that this tiny amount of CFC might inexplicably get into the upper atmosphere in the Antarctic??? Surely the gas could be recovered provided that the tire had not totally failed on the track...

 

A second thought on Steve's "deviation from the ideal of Boyle's law" idea: *** PURE SPECuLATION WARNING *** - and, BTW, Steve is absolutely right that many gas mixtures differ quite a bit from this ideal law. Steam is probably the most obvious example (Adiabatics).

What if the molecular nature of this mix affected the "springiness" or "bounce" (for lack of a better word) factor with the tire/inflation system? Could it have a minor "shock absorbing" factor that kept the tread in better contact on rough surfaces, yet be pretty well dampened against excess rebound?

Also, after thinking about this over the weekend - maybe the ban is more in the nature of keeping everybody honest (or at least decently matched)? Maybe Ferrari knows more about this than anybody else (or at least more research has been done since McL got their paperwork?)

If Ferrari did not want to tell the world, maybe FIA is telling them "you cannot use this Witchcraft, then"?

 

Thanks very much, but as far as I could see, that just said the gas was C02 (!) rather than a blend of CFC - and that it was being banned along with traction control.

I did not see where it said anything about "why"? - "why it was used, how it worked, and why it is being banned..."?

Still reading it and looking for related links -

 

OK, that was from March 2008 - and it speculated that the "gas" - whatever it was, was supposed to cut down on sudden heat buildup if you spun the rear tires or lockied the fronts (as there was no traction control). The gas mix is claimed to be a temperature control device in some unstated manner.

I somehow think that there has to be more to the deal than that - for example, wouldn't you think that drag racers (with all their technical prowess on "traction control" while spinning rear tires like crazy) - would know all about this?

Anyway, don't tires get MORE traction when HOT??? OK, I guess up to a point, but still...

 

Logical on that. It is not going out through the axel spindle and the brakes.

However, think along with me on this - if you release all the air pressure in a small bottle of compressed regular air, it will get a LITTLE colder.

If you dump the pressure in a small CO2 cylinder, it gets quite a bit colder.

If you dump the pressure in a can of Freon - it will form a LOT of frost on the outside.

Could they have some kind of subtle pressure release system to vent some of this CFC gas from inside the tire to thus release the latent heat in the compressed mix out to the atmosphere? As a sort of temperature control device - ??? Surely it could not be anywhere near enough to cool the brakes or anything - does rubber transmit heat well enough from tread to inner liner (and v/v) to make this work at all? Like on the tread, where the rubber meets the road?

Intuitively, this all sounds so far-fetched to me that it hardly seems worth the while of an F1 team, hence my fascination with it all...

Chilling light metal alloys supercold and then letting warm up little by little sounds pretty esoteric too, as a matter of fact - and that seemed important enough to the FIA to get it banned as well.

 

You know, of course, that if you are right (and it seems to me to be the most well reasoned statement so far), that Steve Magnuson was also right in his very first post about the pressure buildup (and hence the 'springiness') and nobody needed my little pet physics thread...