[JetBlack]

Why is NOS used, as an oxygen source, instead of a lighter dose of O2?

 

[Thomas S]

I believe it's because NOS cools the air. The cooler the air, the denser the air, more oxygen to burn. At least that's the way I understand it.

 

[ski]

Jimp is right on the $
http://auto.howstuffworks.com/question259.htm

 

[GTNOS]

yup, they are right. here is why. NOS is N2O, meaning 2 molecules of nitrogen and on molecule of oxygen per part. in its bottle, N20 is a liquid. when you release it, it instantly turns to a super cold gas, the nitrogen and oxygen molecules spit. when they do, the nitrogen becomes EXTREMELY cold (roughly -40 degrees Celsius) in the atmosphere and not only super cools the oxygen molecule around it, but all the other oxygen molecules that are traveling down into the combustion chamber! as i am sure you know, colder air is more dense, has more O2 in it, and can make more power. the biggest advantage of nitrous is its cooling effect. some pro racers even use just to cool the air from their superchargers. they never actually inject it into thier engines. n20 is better at cooling the incoming air than an intercooler could ever be. you could still make power by injecting compressed 02 into your motor, but the effect would probably be a fraction of what it would be with the nitrogen added.

BTW, i know all of this b/c i am a nitrous junkie!!:kooky:

 

[GTNOS]

also, i checked the link posted.. im not saying its totally inaccurate but, n20 does not have to be heated to split the molecules and become cold. i once showed friend of mine how cold n20 is by cranking open my nitrous bottle and holding a bolt with a nut on it in front of the spray with a pair of pliers. the nut and bolt froze. when i dropped the bolt and nut. the bolt broke! be careful if you play with it like that. it can cause really bad cold burns on you.

 

[Thomas S]

also, i checked the link posted.. im not saying its totally inaccurate but, n20 does not have to be heated to split the molecules and become cold. i once showed friend of mine how cold n20 is by cranking open my nitrous bottle and holding a bolt with a nut on it in front of the spray with a pair of pliers. the nut and bolt froze. when i dropped the bolt and nut. the bolt broke! be careful if you play with it like that. it can cause really bad cold burns on you.

Well the nitrous bottle needs to be warmed to a certain temp to keep the pressure between 900-1200psi. I didn't look at the link yet, maybe that's what they meant.

 

[originalsnake]

Im gonna have to chime in on this one. Actually the cooling effect that everyone is talking about is not what creates the additional horsepower, it is a secondary benefit. The real power from nitrous comes from when it is injected and heated in the compression stroke the n20 splits and releases extra oxygen into the system. Furthermore nitrous oxide is extremely dense which acually leads to about 2 times the amount of oxygen than in the air that we and our engines breath. We all should know that more oxygen leads to the burning of more fuel which leads to higher cylinder pressure and equals more power. The cooling effect is only secondary and is not where the real gains come from, but dont get me wrong there is some power gains from the cooling but not anywhere near what the surplus of new oxygen to the engine.

To try to answer the original question here. A direct injection of oxygen instead of nitrous i cant help you with. I would have to guess that it would be way too dangerous. Oxygen causes the combustion of fuel to take place much more rapidly. Think of it as this i believe that air is made up of roughly 79% nitrogen and 21% oxygen and nitrous oxide is 64% nitrogen and 36% oxygen. Now the horsepower gains from this enhancement are tremendous yet can cause problems ie. detonation or much worse if not used correctly. Now think about 100% oxygen shooting into your engine.

 

[ixtlan]

There are two reasons for sure.
Oxygen is very dangerouse and difficult to store safely.
LOX bottles are two bottles in one. In case the inner bottle cracks the outer will contain the O2.
Oxygen boils at -297 degrees F and expands at the rate of 300 times per volume. That makes it difficult to get from point A (Bottle) to B (Intake). If you remember your phisics class, once a liquid reaches boiling point then it no longer gets hotter as it has turned to a gas unless heated externally.
NOS boils at -127.3 F.
Gasoline freezes at around -200 to -300 degress F depending on the blend.
Inject Non-Heated O2 and what you get is a Block of Ice'd Gasoline.
Inject NOS into gasoline with water in it and the water freezes.
What happened to the NOS Shot Dude? :winks


NOS has two advantages:
Safer to store.
Wont freeze yer go-juice.

 

[GTNOS]

Jimp: yeah, that might be what they meant, i only skimmed it. or it might be like originalsnake said and it is the heating in the combustion chamber they are referring to. he did a little better job of explaining it than me.


Originalsnake: i basically said what you are saying. when i said the biggest advantage of nitrous is its cooling effect, i meant biggest advantage over other methods of forced induction such as supercharging, since the nos delivers the o2 and cools it at the same time. i agree with you that the delivery of o2 is the the primary advantage and the cooling effect is secondary. oh yeah, i also failed to mention that 100% compressed 02 is very EXPLOSIVE, and would be dangerous to work with, glad you caught that mistake before some poor sob hooks up his 02 diving tank to his car and blows himself up!!:eyebulge: :tongue

 

[GTNOS]

Oxygen boils at -297 degrees F and expands at the rate of 300 times per volume. That makes it difficult to get from point A (Bottle) to B (Intake). If you remember your phisics class, once a liquid reaches boiling point then it no longer gets hotter as it has turned to a gas unless heated externally.
NOS boils at -127.3 F.
Gasoline freezes at around -200 to -300 degress F depending on the blend.
Inject Non-Heated O2 and what you get is a Block of Ice'd Gasoline.
Inject NOS into gasoline with water in it and the water freezes.

that i didnt know... learn something new everytime i log on!:happyhapp

 

[JetBlack]

There are two reasons for sure.
Oxygen is very dangerouse and difficult to store safely.
LOX bottles are two bottles in one.

Keeping in mind that the bottles of compressed oxygen, aren't liquid. They are compressed gas. It does not become liquid at any point. You *can* purchase liquid O2 bottles but you lose about a percent a day while storing them and they are wildly expensive compared to what people use to weld/cut. Not feasable to anyone but metal scrappers and industry that uses it fast enough. The oxygen bottles you and I use for gas welding and cutting, are compressed gas.

Anytime you decompress gas, it has a cooling effect. Compressing gas heats it. O2 would also cool the charge so that isn't the prime benefit for NOS over oxygen. I am simply wondering why you can't use oxygen gas, instead of nitrous as an oxygen source. It doesn't have to be 100% oxygen and it doesn't have to go in at max volume.

I wonder if the nitrogen in NOS slows the availability of the oxygen by needing to be heated and *then* releasing the oxygen [thus acting to retard the speed of combustion compared to O2 alone]. If you already had nothing but oxygen, perhaps the spark plug would be crossing the line between "igniting the gas and air mixture" and "touching off a bomb".

Maximum in PING [pre-ignition].

 

[originalsnake]

I see where we are going with this one and nobody is going to be able to answer this unless they are very familiar with different compressed gasses. Im assuming that nitrous oxide is used because it is a gas that is readily available and widely manufactured and bottled and contains nearly the perfect ratio of oxygen in the mixture to add power but not be explosive. If there was another gas that contained oxygen molecules in a similar ratio maybe that would be used instead. This is just my guess.