Jump to content
SAU Community

Recommended Posts

I was taking to the tyre dude today as I was getting my T1R's fitted.

He mentioned that for performance cars its best to have nitrogen in the tyres instead of air.

So.. What are the pros and cons? He said @ $9 a fill for one tyre.

What happens if you break down or if you have a punture? What happens.

Does anyone use this stuff for road use? or mainly for track?

Ive search the word nitrogen and nothing comes up in relation to tyres (only one person has said they will do it.).

Any info would be good.

Link to comment
https://www.sau.com.au/forums/topic/92790-nitrogen-filled-tyres/
Share on other sites

I was taking to the tyre dude today as I was getting my T1R's fitted.

He mentioned that for performance cars its best to have nitrogen in the tyres instead of air.

So.. What are the pros and cons? He said @ $9 a fill for one tyre.

What happens if you break down or if you have a punture? What happens.

Does anyone use this stuff for road use? or mainly for track?

Ive search the word nitrogen and nothing comes up in relation to tyres (only one person has said they will do it.).

Any info would be good.

pros.

Nitrogen does not contain moisture and is much more tolerant of change in temp. eg less expansion or retraction therefore keeps a more stable pressure in hotter or colder conditions. Hence they use it in aircraft tyres.

cons.

its heaver than air, its expensive.

What happens if you break down or if u have a puncture?

Common sense tells me to either call for help or change the tyre.

At 9 bucks a tyre i would not waist your money. if u go to the track simply drop the pressure in your tyres. when they warm up they will increase pressure.

Unless you're going to use it for track work, or you've got your own nitrogen pump, I don't think its worth it.

The pros given by Damo are correct. You don't get the changes in tyre pressure that you do with air as the tyre heats up, which makes them more consistent and less likely to overheat.

But its hard to find a pump, and so if you get a slow leak or want to tune your tyre pressures you'll be out of luck.

When I get a second set of rims I'll probably use nitrogen in my track tyres, and use regular air in the street tyres.

As an aside, which tyre dude has been the only one to say they'll do it?

cons.

its heaver than air

Have you got any references for that?

Air is just under 80% nitrogen, and 20% ozygen. You've got 1% Argon, and everything else is just a rounding error.

Oxygen and argon are heavier than nitrogen, so assuming you're scientifically rigorous enough to be comparing the weight at the same temperature and pressure there's no way pure nitrogen could weigh more than air.

To the best of my knowledge you don't have to run higher pressures with pure nitrogen than air but I could be wrong. If so, then I guess nitrogen-filled tyres will weigh more...but you'd have to be a bloody good driver to notice.

Have you got any references for that?

Air is just under 80% nitrogen, and 20% ozygen. You've got 1% Argon, and everything else is just a rounding error.

Oxygen and argon are heavier than nitrogen, so assuming you're scientifically rigorous enough to be comparing the weight at the same temperature and pressure there's no way pure nitrogen could weigh more than air.

To the best of my knowledge you don't have to run higher pressures with pure nitrogen than air but I could be wrong. If so, then I guess nitrogen-filled tyres will weigh more...but you'd have to be a bloody good driver to notice.

Yep your right, got it mixed up. Sorry, had 1 too many beers last night.

Have you got any references for that?

Air is just under 80% nitrogen, and 20% ozygen. You've got 1% Argon, and everything else is just a rounding error.

Oxygen and argon are heavier than nitrogen, so assuming you're scientifically rigorous enough to be comparing the weight at the same temperature and pressure there's no way pure nitrogen could weigh more than air.

To the best of my knowledge you don't have to run higher pressures with pure nitrogen than air but I could be wrong. If so, then I guess nitrogen-filled tyres will weigh more...but you'd have to be a bloody good driver to notice.

The 100% nitrogen filled tyres don't increase pressures as much as ambient air does when the tyres get hot. So they are more stable in their tyre pressures. My understanding is this is mostly due to the humidity (H2O) pressent in ambient air. Which, when it gets hot, breaks down into hydrogen and oxygen and increases the pressure accordingly.

So when they say "humidity is 40%", what does that mean to the 79.5/19.5/1 mixture? Does it become 47.5/11.5/1/40?

If so, that's why the pressure goes up so much if you have 40% of the contents of the tyre splittting into hydrogen and oxygen.

:rolleyes: cheers :)

most of the benefits you get out of nitrogen filled tyres, can be achieved by using dry compressed air.

Moisture content in the gas you use plays a much larger part than the gas itself.

Aircraft tyres tend to use them because it's an inert gas, and reduces the risk of fires/tyre explosions.

Which, when it gets hot, breaks down into hydrogen and oxygen and increases the pressure accordingly.

I'm not sure what the activation energy of water is, but are you sure that there's enough heat in the tyres to do that kind of thing? The last time I hit the track my tyres only reached around 50 degrees on the surface of the rubber.

And what do you do afterwards? Anyone who's studied the history of airships knows how safe hydrogen and oxygen are when mixed together and heat is applied. Also, since gases occupy more volume per molar count than liquids, that would leave your tyres with a higher "at rest" air pressure afterwards. Of course, depending on the humidity in the tyre in the first place it may or may not be detectable with a commercially available gauge.

If that was enough to break down hydrogen and oxygen, boiling water in a semi-sealed environment (like a kettle) where the boiling water vapour is kept at 100 degrees+ before being vented to the atmosphere would probably get you killed if you smoked anywhere near it.

Once again this is pure speculation on my part (I wouldn't even call it a hypothesis since I'm not that up on chemistry), but it just seems like if there was enough heat in tyres to break water down to its base elements there would be a lot more cases of tyre blowouts during enduro races.

Trust me, theres no way you'd be splittin H2O in your tires. :D)) (Drawing some vague knowledge from uni chem) H2O just wont spontaneously split in 2 on its own without some sort of chemical or metallic catalyst or current.

To put this into perspective, to get N2O (Nawwss) to split into nitrogen and oxygen spontaneously, it needs to be exposed in combustion chamber (1000C) for it to give you the O2 to give you the 'go'. Unfortunately even so, this aint the same with H2O. Tyres at 1000C anyone? Haha

Boiling water just means the water has changed from a liquid to a gaseous state. It doesnt mean the water is splitting up, or it wouldnt be water anymore would it? (Ie water vapour)

Edited by Busky2k

The increased temperature just means the molecules will move about faster and with more energy, which equates to a rise in pressure. You are not actually spliting the H20. PV = MrT is the equation :D P = Pressure, V = Volume, M = Molecules, T = Temp. and r is a constant.

From my understanding having N2 filled tyres only makes pressure more predictable and less changing under temperature changes. I have seen you can get it for road tyres now but can't see the value. Particularly at $9 a corner...

BTW for those saying its good for race cars not road cars, I think its the opposite.

Its great for your average car driver, set it once when you put the tyres on, and throughout the tyre's life it won't change by more than 1 or 2 psi (assuming no leaks). Perfect for set and forget and you always get optimal tyre performance

On a race track on the other hand, you can expect to need to change the tyre pressures most sessions, and that means you would have to take nitrogen with you. For track use pressures on the same car are affected by the direction of the track (clockwise or anti), track temp that day, and even fine tuning of the car's balance.

I got my tyres filled with nitrogen mainly because of what Duncan said:

Its great for your average car driver, set it once when you put the tyres on, and throughout the tyre's life it won't change by more than 1 or 2 psi (assuming no leaks). Perfect for set and forget and you always get optimal tyre performance

But does it work? Have your pressures changed?

Could you please do a measure now and post what pressure you put in, what it is now and the time frame? I am currious to see if this actually works or not.

Real world experiences;

I know that on a humid race day we have to bleed off more pressure in the tyres (as they heatup) than on a dry day. Note that is using a compressor with no water filter to pump up the tyres. I always put that down to more water vapour in the air. Not water itself.

I know that using air from a cylinder we still have to bleed off pressure in the tyres, just not as much as what we do out of the compressor. I always put that down to less (maybe even zero) water vapour in the cylinder.

I know that nitrogen filled tyres take even less bleeding off, I put that down to the lower expansion properties (due to heat) of the nitrogen versus air. ie oxygen (+ other gases) expands more when it is heated from ~20 degrees to ~70 degress. I don't know whether that is true or not, all I know is there is less expension from 100% nitrogen

:D cheers :(

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yea that’s why I said ima test them with multimeter and see the reads.
    • Only at idle. Isn’t a problem when rev it seems.
    • @Haggerty This seems silly to ask, but are you confident in your ability to tune the Haltech?  
    • Next on the to-do list was an oil and filter change. Nothing exciting to add here except the oil filter is in a really stupid place (facing the engine mount/subframe/steering rack). GReddy do a relocation kit which puts it towards the gearbox, I would have preferred towards the front but there's obviously a lot more stuff there. Something I'll have to look at for the next service perhaps. First time using Valvoline oil, although I can't see it being any different to most other brands Nice... The oil filter location... At least the subframe wont rust any time soon I picked up a genuine fuel filter, this is part of the fuel pump assembly inside the fuel tank. Access can be found underneath the rear seat, you'll see this triangular cover Remove the 3x plastic 10mm nuts and lift the cover up, pushing the rubber grommet through The yellow fuel line clips push out in opposite directions, remove these completely. The two moulded fuel lines can now pull upwards to disconnect, along with the wire electrical plug. There's 8x 8mm bolts that secure the black retaining ring. The fuel pump assembly is now ready to lift out. Be mindful of the fuel hose on the side, the hose clamp on mine was catching the hose preventing it from lifting up The fuel pump/filter has an upper and lower section held on by 4 pressure clips. These did take a little bit of force, it sounded like the plastic tabs were going to break but they didn't (don't worry!) The lower section helps mount the fuel pump, there's a circular rubber gasket/grommet/seal thing on the bottom where the sock is. Undo the hose clip on the short fuel hose on the side to disconnect it from the 3 way distribution pipe to be able to lift the upper half away. Don't forget to unplug the fuel pump too! There's a few rubber O rings that will need transferring to the new filter housing, I show these in the video at the bottom of this write up. Reassembly is the reverse Here's a photo of the new filter installed, you'll be able to see where the tabs are more clearing against the yellow OEM plastic Once the assembly is re-installed, I turned the engine over a few times to help build up fuel pressure. I did panic when the car stopped turning over but I could hear the fuel pump making a noise. It eventually started and has been fine since. Found my 'lucky' coin underneath the rear seat too The Youtube video can be seen here: https://www.youtube.com/watch?v=uLJ65pmQt44&t=6s
    • It was picked up on the MOT/Inspection that the offside front wheel bearing had excessive play along with the ball joint. It made sense to do both sides so I sourced a pair of spare IS200 hubs to do the swap. Unfortunately I don't have any photos of the strip down but here's a quick run down. On the back of the hub is a large circular dust cover, using a flat head screw driver and a mallet I prised it off. Underneath will reveal a 32mm hub nut (impact gun recommended). With the hub nut removed the ABS ring can be removed (I ended up using a magnetic pick up tool to help). Next up is to remove the stub axle, this was a little trickier due to limited tools. I tried a 3 leg puller but the gap between the hub and stub axle wasn't enough for the legs to get in and under. Next option was a lump hammer and someone pulling the stub axle at the same time. After a few heavy hits it released. The lower bearing race had seized itself onto the stub axle, which was fine because I was replacing them anyway. With the upper bearing race removed and the grease cleaned off they looked like this The left one looked pristine inside but gave us the most trouble. The right one had some surface rust but came apart in a single hit, figure that out?! I got a local garage to press the new wheel bearings in, reassemble was the opposite and didn't take long at all. Removing the hub itself was simple. Starting with removing the brake caliper, 2x 14mm bolts for the caliper slider and 2x 19mm? for the carrier > hub bolts. I used a cable tie to secure the caliper to the upper arm so it was out of the way, there's a 10mm bolt securing the ABS sensor on. With the brake disc removed from the hub next are the three castle nuts for the upper and lower ball joints and track rod end. Two of these had their own R clip and one split pin. A few hits with the hammer and they're released (I left the castle nuts on by a couple of turns), the track rod ends gave me the most grief and I may have nipped the boots (oops). Fitting is the reversal and is very quick and easy to do. The lower ball joints are held onto the hub by 2x 17mm bolts. The castle nut did increase in socket size to 22mm from memory (this may vary from supplier) The two front tyres weren't in great condition, so I had those replaced with some budget tyres for the time being. I'll be replacing the wheels and tyres in the future, this was to get me on the road without the worry of the police hassling me.
×
×
  • Create New...