williamr

I don't expect that that's a serious comment, but just in case anybody thinks it is, try blowing up an ordinary rubber balloon with helium and see how long it takes to go flat.

And on the fire issue - fire is just a chemical reaction. It's just two substances combining exothermically. Oxygen is very volatile and combines very easily with other substances, such as petrol or hydrogen. A pure oxygen atmosphere is safe because there's nothing for it to combine with. Oxygen combined with air is safe because the main gas, nitrogen, is inert. Other substances will burn in air because most of the non-nitrogen component is oxygen.

High oxygen levels are dangerous because it's easier for small amounts of other volatiles to combine very rapidly causing an explosion, but oxygen in the absence of other volatiles is safe, just like petrol is safe until there's something (oxygen) to combine with it. Lower oxygen levels mean that the reaction is slower, so you get fire rather than explosion. Put it another way - an explosion is a fast fire.

The Apollo fire was oxygen and hydrogen combining. Either gas on its own would have been safe.

Rob.

NavyBob

I'm with Rob on the lack of effectiveness of nitrogen on the street. In a competitive track situation, then it probably makes sense.

I've dealt with TPMS on a few vehicles and all the ones I saw worked via the wheel speed sensors. I'm aware there have been some with an actual sensor inside the wheel, but I think those have largely or entirely been supplanted by monitoring wheel speed differentials for signs of a tire that's gone down. I doubt if this is super accurate (I've seen TPMS on a newer 911 be several psi off the actual pressures), but it's enough to satisfy the government's requirement to alert a completely oblivious driver when they have a tire down 25% from the recommended pressure.

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weebel

I am not sure where AFR came up but yes it is the fuel that is burning, the air just feeds the fire. There is some oxygen that is broken down but its not really burning, its more of an accelerate really.

I can see using nitrogen in your tires if you are racing competitively, and I mean real competitively, but anything other then air on the street is kind of retarded. I would even use air for a track bike. You are not going to need nitro on a street bike and if a tire gets a little low well oh shit, what are you going to do now? Just stop by a gas station and top it off. If you are getting your tires hot enough that nitro makes a difference on the street you wont have your license for long. Even if you are, you are not racing for position so it doesnt matter.

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Sev

I don't think you mean accelerant. I think you mean it is necessary in conjunction with heat and a fuel source. Without oxygen your fuel will not burn at all. Not burn slower.

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Of course I'm generalizing from a single example here, but everyone does that. At least I do.

weebel

Yes I know. It acts like a fuel not an accelerate. Well unless we are talking torches. I just dont know how to explain it simply is all. To be honest I do not know the chemical reasons why oxygen is needed for fire to burn, I just know it does. I should look that up and learn something. I would guess that the molecules are broken down along with the wood / gas ect and continues the reaction (like combining fuels).

I just figured saying it "acts sort of like" an accelerant was the simplest way to put it. +1 for you.

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whitehendrix

i'm gonna say nitrogen in ANY passenger car is a fuckin scam. i see the value in race applications because, well, you don't get much more race knowledge than being on an ALMS LMP900 crew racing a $2 million audi. or my having been building bikes for 10 years, and most of them as race bikes..

Nitrogen in any street application is pointless. in racing, yes. its great, especially if you're streaming telemetry on suspension dynamics in real time. getting to see tire temps and ride height and pressure vary as little as possible across the board are all nice when theres an ass ton of things to adjust to balance the car out. same on a bike. now, short of MotoGP, you won't see suspension telemetry on most bikes. sometimes linear encoders for ride height every now and again, but you won't see 3 axis accelerometers, real time tire temp and pressure, brake fluid pressure, tps, suspension travel, and ride height being streamed.. lol

anyway.. yeah. nitrogen is pointless in any non-race application.

and as previously stated. atmosphere on this planet just so happens to be mainly nitrogen anyway.

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weebel

screw it, Im going to fill my tires with pure oxygen thats where its at. LOL could you imagine? I wonder if they would get hot enough to pop.

Whitey is the man on this. Unless you are a pro racer, in wich your crew is going to do the work for you, just worry about tire pressure using a generic air pump. Your riding skill and practice is going to be what matters for what people here are doing.

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whitehendrix

if the oxygen is at the right pressure and in a reactive enough gas compound, it'll autoignite for sure. but pure oxygen is not flammable. its more of a catalyst. like nitrous won't go off when you light it. it releases oxygen, thus it's being defined an an oxidizer. the oxygen released is what reacts with ambient fuel and air creating more power.

simply popping the tire is a function of pressure rise over temp rise.. an inert gas ( like nitrogen! ) is immune to that for the most part. thus its usage in racing as i mentioned before. its stable as fuck.

but yeah to get autoignition temps high enough to , lets say set off an oxygen/acetelyne mix, the tires would melt before the AIT was reached.

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J_Fuggin_T

My gpx does that




Sent from my iPhone using Motorcycle.com Free App

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whitehendrix

probably not at the level of what i worked with

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