3GRX7

iTrader: (1)

I keep hearing commercials stating improved safety and performance with nitrogen filled tires...before I do this, I'd like to hear any comments the gurus herehave on the subject.

Thanks


http://www.whynitrofill.com/index2.php

Herblenny

iTrader: (13)

LOL! I guess they don't know that breathing air is comprised of 78% Nitrogen.

F0RSAKEN

100% nitrogen isnt affected by tempertures like the air we breathe (I think, so dont quote me on that), and so you wont see any change in tire pressures when your tires heat/cool down i.e. while racing, which is good.

7-sins

We have a Costco around here that does it. I have Nitrogen in my beaters tires. Its great, I never have to add any, there is not much pressure fluctuation at all. I will put it in the 7s tires eventually... just need to get her on the road first.

DaveW

N2 (in place of moisture-laden air) can help with 3 problems:

1. Since the N2 is dry, there is no water vapor to condense inside the tire. Moisture condensation gives large pressure variation from cold to warm as the moisture condenses and revaporizes.
2. Since N2 molecules are larger than O2 molecules, air leaks more slowly from the tire, and pressures remain more constant.
3. Since O2 and water are not present, the gas inside the tire is inert, and rust and oxidation won't occur.

I use dry air (dessicant dryer) since moisture content is my main concern.

For practical purposes, if there is little contained moisture, you've gotten most of the benefits of N2. All gasses expand similarly with temperature increases, as long as no moisture is present, so there is no benefit there.

Dave

Kansas JoyRide

iTrader: (1)

As you can see by my post count, I don't often post info on this site. There are always lots of folks that have forgotten more than I will ever know about these cars. Having said that, I have been running N2 in my FD for over a year now with no measurable pressure loss. I manage truck plazas for a living. We offer N2 to our professional truck drivers as a value added service with the purchase of truck tires at our shops and terefore had easy access. I don't track my car but feel N2 is a good idea if you live in a location with big temp. extremes. In central Kansas where I live temps range from below zero in the winter to over 100 in the summer. As I drive my car all year round, I believe N2 has served me well, however it didn't cost me anything to put it in my car. I have no idea what shops are charging to inflate a car tire but I don't think I would pay for it unless I planned to track my car. Hope that helped.

Efini_7

iTrader: (1)

I got my tires filled with nitrous when they were put on...so far nothing but good things to say about it, on street and the track. The only thing is that it cost me a bit more than being filled with air.

FDNewbie

iTrader: (10)

Just a shot in the dark, but doing a search *may* help...

https://www.rx7club.com/showpost.php...2&postcount=40
https://www.rx7club.com/automotive-news-lounge-22/nitrogen-now-available-filling-up-your-tires-428085/

~Ramy

sukimoto

iTrader: (1)

I work at belle tire and just recently 'nitro-nized' my tires, im taking my car to the track in a little under 2 weeks so ill have to see

DamonB

Nitrogen in road car tires is a complete crock.

Aircraft use nitrogen for a number of reasons, none of which concern cars. In fact large transport aircraft are mandated by the FAA to fill their tires with nitrogen. There are a few reason for this:

It is believed that several aircraft have been damaged or lost due to instantaneous combustion of the tire in flight due to the oxygen in the tire reacting with volatile gases from the tire rubber. Nitrogen is inert and will not do this. Again recall that aircraft tires must operate over wildly varying altitudes, temperatures and pressures.

Nitrogen reduces the chances of aircraft brake fires. Part of an aircraft's certification is it being able to withstand a certain amount of time (3 minutes I think?) with the brakes ON FIRE without the aircraft itself catching fire. Obviously if the tire held plain compressed air containing oxygen this would fuel the fire when the tire bursts from flame, while inert nitrogen will not.

Aircraft tires are required to go from 0 mph to 200 or so mph at the instant of touchdown. After the tire instantly heats up from accelerating to 200 mph it then heats up some more when asked to support tens of thousands of pounds of aircraft. Then it heats up yet even more when it's asked to stop the tens of thousands of pounds of aircraft. Aircraft tires run HOT. Nitrogen helps here because it's consistent; there's no concern about how wet the air is from an air compressor in Burbank or Tinbuctu and again nitrogen will not support combustion.

Aircraft operate at tens of thousands of feet where the air is very cold. Any moisture in the tire could freeze and cause pressure variances as well as chunks of ice causing wildly imbalanced tires during landing.

Aircraft tires are pressurized to hundreds of psi. It's far faster, cheaper and more convenient to fill them from a 1,500 psi bottle than from an air compressor.

The extremely high tire pressures in aircraft greatly increase the speed of oxidation for the tire and its wheel, again making it much more important to use a dry gas for inflation.

In a nut shell aircraft use nitrogen because it is dry and will not support combustion. Road car tires do not share the operating conditions of aircraft tires and thus do not require such worries.

FDNewbie

iTrader: (10)

Damon, but wouldn't you advocate running nitrogen in a track car, where tire temps will fluctuate? My understanding is this would minimize the risk of a blowout...

The Griffin

That's correct,as larger aircraft have safety fuse plugs that are supposed to melt at elevated rim temps.If you have water vapour present the pressure will skyrocket when the inner tire is on fire and the tire will explode before the fuse plug melts.AeroMexico destroyed a Boeing 727 by filling tires with compressed air and then having the unfortunate problem of a dragging brake causing tire explosion and a subseqent molten rubber fire in the wheel wells burning through control cables and hydraulics.
It probably doesn't do much in a car other then maybe inhibit rim corrosion.

Juan

iTrader: (28)

How many of us actually have corroded wheels or tires that have gone bad because of the moisture level in the air? I wouldnt go out of my way to put nitrogen into my tires because a commercial says I should. If the shop installing my tires uses it, I wont stop them. Sounds like good marketing more than anything.

DamonB

Maybe. If I were a pro, sure. Nobody else is going to be able to tell the difference. Nitrogen will never hurt but just like anything else do you need it? In most cases no. I wouldn't run nitrogen in my tires unless it was getting done for free.

If your tires currently have plain 'ole air in them anybody charging you money to put nitrogen in the tires had better be pulling and holding a vacuum on the tires to boil the water vapor out before refilling them with nitrogen. If they don't do that you're getting screwed; there's still water vapor in the tire. If the guys mounting new tires aren't using nitrogen to seat the beads you've still got water vapor in your tire. Lots of shops are offering nitrogen but very, very few of them are doing it properly, they're merely upselling you because you perceive benefits in nitrogen.

Tire temps (and therefore tire pressure) will rise at the same rate no matter what gas you put in the tire. PV=nRT. Tire pressure goes up because as the tire heats the gas inside the tire is heated and therefore expands. If there is any water vapor once the water vapor gets hot enough it will turn into steam. This change of state from liquid to gas causes an even greater rise in pressure because a given mass of steam occupies much more volume than it would in liquid form. In the case of water vapor inside the tire pressure rises at a certain linear rate until the water turns to steam. Then the rate of pressure increase will ramp sharply up. The entire point of nitrogen is to keep water vapor and therefore steam out of the tire. That's it; there's no magic going on. Any dry gas would give the exact same result.

Think about road cars. If you can't get the tire hot enough to turn water vapor into steam (NO street car will get tires near that hot unless they're nearly flat to begin with) then you're not concerned with water vapor in the tire. It just sits in there. Fact is I could go to any parking lot in any city and let 5 psi out of everybody's tires and 99.9% of those people wouldn't be able to tell a difference when they drove home. You don't need nitrogen in your street tires.

The only reason to use nitrogen on a racecar (where you do sweat things like 1/2 psi of hot tire pressure) is because nitrogen is a dry gas. Dry compressed air would be every bit as good but the only people with a proper compressed air drier tend to be the guys using high quality paint guns. Nitrogen is convenient in this case as it's readily available in easily transported bottles.

Nobody. When you start running 300+ psi tire pressures and hundreds of degrees of temperature like aircraft do then corrosion becomes a bigger problem. Cars don't have that problem. A street tire will oxidize less with a dry gas inside but fact is you'll wear the tread out or UV from the sun will kill the tire long before it ever rots from the inside out, I don't care how much water is in there.

FDNewbie

iTrader: (10)

Hey Damon,

Thanks once again for clarifying things I got the idea of running nitrogen in a racecar from this post: https://www.rx7club.com/showpost.php...2&postcount=40.

I'm w/ you there, but the only thing I don't understand/agree w/ is when you say steam occupies much more volume than it would in liquid form. At rest, yes. But this is in a pressurized tire, is it not? And being that liquid is not compressible (for the most part), but gas is, wouldn't the gas in the tire occupy LESS volume than the liquid, due to the pressure compressing it?

Thanks
~Ramy

Herblenny

iTrader: (13)

I agree with Damon.. I think this thing is a BS.. just like Cermet coated engines and how people think its a magical solution to their "street" driven cars.. LOL!

No way in my lifetime with my FD that I'll be pushing so hard to fill my tires with nitrogen. I agree with you about drier in the line for compressed air. I've seen many that moisture will comes out of the line because of lack of drier.

Ramy, also think about how much air you'll be putting in your tires.. Depend on the size and such, you might not even put as much air. A stock 16 vs 18 inch wheels with same width might not hold same volume. I think if people are so worried about filling their tires with nitrogen, they should first test what kind of tires they are purchasing..

DamonB

This is a fact.

Fill a tupperware dish to the brim and tightly cap it. Stick it in the microwave and watch it explode. If the water didn't expand it wouldn't blow the cap off, it would merely get hot. If it in fact shrank you would see the container attempt to implode. This of course doesn't happen.

If the water turns to steam you can count on the fact it will expand into a greater volume than it would have if it were merely hot water. It must; it became steam. Steam is steam no matter where it is. Pressure in the tire will insist the water must reach a higher temp to become steam than it would if it weren't under pressure, but it won't prevent it form happening.

Your cooling system for instance is pressurized for this exact reason. Ordinary water boils at 212 F. Ordinary water under 15 psi of pressure boils at about 240 F. Ordinary water in a vacuum will boil at room temperature (which is why you pull a vac on the a/c system during service, to boil all the water out and thus ensure there is nothing inside the system which can freeze).

If you could generate enough pressure inside a tire where steam is already present you could condense the steam back into liquid, but this would not happen without you adding energy to the system in some fashion. It would never happen on its own (even this assumes the tire wouldn't explode at the pressure required to condense the steam).

capt murph

That is great stuff Damon. I'll stick to the cheap AIR.
And I don't mind changing the winter to summer air as part of good maintenance.
arg arg snork

Juan

iTrader: (28)

Yup. The majority of the population is stupid when it comes to tire care. The only thing nitrogen in their tires will do is raise their smug level to the point where you want to punch them.

FDNewbie

iTrader: (10)

Great example! Thanks for the explanation Damon. I see the difference between the two

~Ramy

jgrewe

iTrader: (1)

As Damon explained very well dry air will function just as well as nitrogen for 99.9% of the population. Racers use Nitrogen because we have it available in big bottles at the track, we run the air guns on it as well. Its easier than hauling a compressor around.

rexset

ok ,
lately I have seen a very good cars filled with Nitrogen from the factory ex:
Nissan GTR R35 ($100K + car)
Lamborgini Gallardo Ultralegera edition ($350K + car)
I have seen that cars with the valve cup of nitrogen with my own eyes, so now the question is : which is the ideal pressure for Nitrogen in the FD3S ???
Cause the pressure for the tire is calculate considering the air expansion with the T° , so If you inflate with N2 , it will not expand at hi T° , so meaby you should inflate more the tire with N2 than normal air.
I will go with nitrogen for sure in the next wheels change, plus I like the way the valve cups looks in the wheel.

turbo10th

iTrader: (6)

I was bored at my dealership(back when i was a porter) i filled my tires up on my FC and blew the engine a couple weeks later. So it sat for like 3 months and the tire pressure stayed the same as when i filled them.
Pros
tires stay inflated
Cons
blows rotarys

dgeesaman

iTrader: (7)

Use the same pressure.

The only place it may change your tire pressure settings is on the track, since the nitrogen contains less water vapor and will increase less as the tire warms. Of course if you're on the track you're familiar with how much heat causes your pressures to rise and you'll adjust accordingly.

rexset

Thanks you very much that was the answer that I was waiting for

Do you know the standard wheel pressure for the 235/45 R17 front and the 255/40 R17 rear (is the japan spec FD3s)