Nitrogen instead of compressed air
Discussion
mmm-five said:
What problem are you trying to solve?
Scientifically, rather than purely in a tyre-filling scenario...
If you're comparing completely dry gases, then there's less than 1% difference in heat-related pressure increases between compressed air and pure nitrogen.
Moisture levels would make more difference as temps rise as this will expand more than any of the other gases in there.
It might matter in Formula 1 where 1% is meaningful, but probably not in club/national racing levels.
i,m trying to find a good start point of inflation from cold, if i wanted to end up at 35psi hot what should i start with . I used to start on compressed air 22psi cold to reach 30psi hot.Scientifically, rather than purely in a tyre-filling scenario...
If you're comparing completely dry gases, then there's less than 1% difference in heat-related pressure increases between compressed air and pure nitrogen.
Moisture levels would make more difference as temps rise as this will expand more than any of the other gases in there.
It might matter in Formula 1 where 1% is meaningful, but probably not in club/national racing levels.
TimCrighton said:
Ideally use it on newly fitted tyres.
The benefit of it, to those nay sayers above, is that in many cars tyre pressures are in effect part of the combined spring rate (as the tyre compression and side wall movement allows some initially element of damping and movement before the suspension components are engaged). Also it can be desirable for example to maintain a softer tyre pressure and allow the tyre sidewall to roll and/or the contact patch to be enlarged - sidewall movement also generates heat which increased pressure and therefore reduces this element over time. Additionally where a car is running over long periods it can be advantageous to control or help to control the growth in tyre pressures over a long stint.
We use it in several of our cars and it serves a purpose.
Like everything you need to test it to see what it will do in your car but for us where as we might have seen a 6-7 psi increase cold to hot that might be reduced to 2-3 psi with Nitrogen.
Tim I take compliments and insults from those that know no better LOL, your point about stabalising pressure over a period of time is going to save a lot of faff. I was thinking that an advantage to already been at pressure from the get go would give me an advantage into the first few laps all be it heat will still take time but less to come up,using nitrogen. There is obviously an advantage other wise why would all the top teams with top cars be using it. I use 305 645 18 tyres so will as you surgest start 3 psi down and wave good bye to the nay sayers LOL The benefit of it, to those nay sayers above, is that in many cars tyre pressures are in effect part of the combined spring rate (as the tyre compression and side wall movement allows some initially element of damping and movement before the suspension components are engaged). Also it can be desirable for example to maintain a softer tyre pressure and allow the tyre sidewall to roll and/or the contact patch to be enlarged - sidewall movement also generates heat which increased pressure and therefore reduces this element over time. Additionally where a car is running over long periods it can be advantageous to control or help to control the growth in tyre pressures over a long stint.
We use it in several of our cars and it serves a purpose.
Like everything you need to test it to see what it will do in your car but for us where as we might have seen a 6-7 psi increase cold to hot that might be reduced to 2-3 psi with Nitrogen.
Tim will see you in anglesey later in the year i hope i,m using it on this LOL................................................
20200820_070241 by flat chat, on Flickr
20200820_070241 by flat chat, on Flickrliner33 said:
We used to use dry air from dive cylinders when drag racing gave more consistent results which were key when you are talking about 1/4 of a psi and less than 8 psi to start with . Easy to source also
i had thought of that and went for nitrogen because it is more stable over time. carl_w said:
Yes, because compressor air has water vapour in it. I'm trying to understand your use of nitrogen vs divers' dry air. Surely for motorsport applications they are equivalent? Maybe if you're keeping the gas in the tyres for months there will be a difference.
all tyres be it road or motorsport will contain water within the carcase of the tyre. nitrogen does not obsorb water molicules so thats why i went with nitrogen .Clearly some will not see the benifits and it is i think just a small advantage but all those small advantages add up to a few tenths a lap. who doln,t love a plastic trophy wink. as an aside divers air and nitrogen about the same price .leef44 said:
I've looked at the various options and found this one to be the most economical.
no one said motorsport was cheap and as i can afford to do some think different why not ? nitrogen is cheap to buy in my opinion, granted not as cheap as compressor air but thats not what i wanted to know. Gassing Station | UK Club Motorsport | Top of Page | What's New | My Stuff