First of all, what does nitrous exactly do? I know it has cooling effect and that the oxygen molecule in the n2o is used as extra oxygen = air, but can some give me detail?

Why the bottle warmer?

Why do people retard their ignition timing for nitrous?

Also what does purging do other than it looks cool?

This is for my roommate, what the best remote bottle opener in the market? He says that he's heard NOS one getting stuck open.

Oh yeah..why do people use colder spark plugs?

Next topic, any one know anything about the propane injection?

Jay Kim

 

i'm no nitrous expert, but i used it for a while. feel free to correct me if i'm wrong about anything...but here's what i know:

bottle warmer is to try and keep the pressure somewhat constant. nitrous works best at a certain pressure. and as we all know temperature affects pressure. and vice versa.

purging cleans the lines of air. air's sometimes trapped in the lines when the bottle is opened/closed.

you have to retard the timing to avoid detonation when using nitrous. the colder plug does what it can to avoid detonation as well.

again...correct me if i'm wrong

 

I haven't used nitrous, so I don't know much about the usage stuff, but I think I can answer your first and last questions... nitrous oxide is rich in oxygen. The chemical formula is N20. It contains more oxygen per unit than gasoline, which is a big mixture of hydrocarbons.

Nitrous increases power because the increased oxygen adds energy to combustion. Nitrous oxide is simply a way of getting more oxygen into the combustion chamber.

I haven't heard of many cars running propane injection, but it's likely a similar situation. More oxygen, so more power.

 

and as you mentioned the cooling effect of the nitrous also increases oxygen density... that is colder air contains more oxygen molecules than does warmer air of the same volume.

 

Yeah... but mainly, the benefit is in the oxygen gained from the nitrous oxide itself.

Usually, the nitrous is injected into the intake manifold runners somewhere near the fuel injectors. Air is pulled into the car's intake well before that point. Despite cooling when it contacts the nitrous, the air can't "gain" more oxygen when it cools because the engine's intake system is sealed after the air enters.

The air contracts as it cools... or it becomes more dense, but I don't think that change increases power nearly as much as the added oxygen from the nitrous.

 

I know that nitrous is an accelerator. What the hell does that mean?

Jay Kim

 

if you have more oxygen then that means that there is a bigger explosion in the combustion chamber and a bigger explosion makes pistons move a lot faster there fore making a lot more horspower

 

Okay kids...

Nitrous Oxide, N2O. That means two Nitrogen and one Oxygen atoms. As it is used in cars, it is stored in a bottle under pressure, as a liquid, allowing much more to be stored if it were a gas only. When the valve is opened on a pressurized vessel, the pressure is reduced, causing the liquid to boil off as a gas. This can only happen if the temperature is warm enough relative to the pressurized liquid. A tank heater means the liquid will always readly turn to a gas. As some of you know, venting off the gas will make the tank get colder (expanding gas) which can reduce pressure to the point of not being useful, hence the heater.

So this very cold gas is sprayed into the intake manifold. Right there is a big gain since you're cooling off the incoming air. So once in the combustion chamber you have air, gas, and N2O. Now what. When NO2 is heated to about 550 deg F, it decomposes into N2 and O. Now we're getting somewhere. You now have much more oxygen... but for what... burning fuel right? But what if you just plumb in a bottle of N2O and nothing else. It means the normal combustion is going to be thrown way, way, off because of all the extra O. It also means the engine is going to burn very very lean since there is more O but no additional gasoline. This condition will absolutely destroy your engine... as many have found out.

The way to solve this is to anticipate the additional O and ALSO add extra gas. That is where the extra power comes from, the extra gas, not the Nitrous itself. The N2O is simply the "facilitator" providing more oxygen for extra gas.

There you go.


[Modified by kb58, 6:09 PM 12/15/2002]

 

I can answer some of these:
Purging is for getting all the air out of the N2O lines, to make sure the air/fuel ratio won't be wrong once injecting starts. That, and to look popular. I mean, the vent could be anywhere, but no, insecure people do the "look at me" think by mounting them high and visible.

Colder sparkplugs:
Since the heat of combustion will be greater, you don't want detonation happening off the tip of the overheated sparkplug. Use a colder plug and avoid that possibility.


[Modified by kb58, 6:09 PM 12/15/2002]

 

LOL, dude, the chemical formula for nitrous oxide is N20

AllMotorMonster+, your question has been answered already, there is more oxygen in nitrous oxide than in air (per mole). Later I'll probably look up the composition of air, off the top of my head it's mostly nitrogen.

 

air = ~21% oxygen ~70% nitrogen
then theres water wapor and some other stuff

 

since on the topic of nitrous, wats the difference between a 'dry' and a 'wet' system. i've read of both, but i'm not sure what they r. and two, how come when i see an add for nitrous (NOS in particular) the bottle in the add says non-flamable? that sounds like a bunch of BS, but then maybe i'm wrong, cuz i really dont kno. thanks for the info.

 

That's what I thought N2O. According to VSEPR theory at least.

Nitrous by itself is not a flammable substance. Nitrous itself won't catch on fire. But let's say you're burning a log and you spray nitrous oxide or pure oxygen on it. The log is the carbon fuel for the fire. And it might seem might the n2o or o2 is burning because the flame will get bigger. But in the end, when the log's all burnt up, you'll notice that no matter how much n2o or o2 you spray on a splinter, they won't catch on fire.

That's why people consider n2o as FI rather a fuel. Also that's why when you don't add extra fuel with nitrous, your car will detonate. As you might know already, engines combust(fast burn), not detonate(explosion) to make power. If you have too much air, the mixture will decinegrate rather than burn. There are two ways to adding the fuel to accomodate the additional oxygen molecules, dry and wet.

Dry system means that you inject nitrous in with the air and it distributes through each cylinder by the intake mani, just like how air is in a stock intake system. The fuel is regulated by monitoring the fuel pressure, and by extending the duty cycle of stock injectors. The disadvantage of having a dry system is that you risk not having even distribution of nitrous oxide in each cylinder which could lead to very undesirable situations. Another thing is that in a dry system, amount of fuel entering being injected with the nitrous is not accurately measured, but rather more like a safe guess. Advantage is having a dry setup is 1)very simple and easy to install and uninstall, and 2) less mechanical "variables" in the mix, as preludeboy likes to put it. This mechanical variable in a dry system is the nitrous solenoid, but if that goes bad, only thing that'll happen is that you'll, at most, bog due to more fuel dumped in. But in a wet system, there are nitrous solenoid and also a fuel solenoid. If the nitrous solenoid craps out, the most that'll happen is you run rich and bog, like the dry system. But what happens, what if the fuel solenoid craps out? You're looking at possible, almost certain detonation, because you're adding more air, but not additional fuel that it needs. There's no way of telling if the fuel solenoid craps out, because it's completely seperate system from the stock fuel system and your ECU won't have a clue what the hell just happened to the motor when it blows. Now, advantage of having a wet, direct port specifically, system is that you're injecting even shot of nitrous to each cylinder and the lag is not as significant as a dry setup would be.

Now there is another system at use, called plate system. They employ a plate, a spacer, between the intake manifold and the head, injecting nitrous from the plate. It has a tube going through it and it resembles those mist sprayers that restaurants use on hot days.

that's all I know. Can someone elaborate on why wet system is more stable than a dry system?

jay Kim

 

ey man, thanks for all that info, that helped out a lot. i learned a lot tonight. i've always had trouble with those questions.

 

what they have said about n20 is correct but as for propane injection i think thats more for diesels then gas engines, but i not sure.

 

would any of you guys happen to know at what temperature water seperates into h2 and o2? I guess technically it would be 2h2 and o2, but my chemistry teacher isnt around, so shhhhhhh

I guess Im just trying to equate water injection and nitrous

 

What was said was very true, i know a little bit- dry systems are good as long as the shot is not very high. you can only get so much fuel in there w/ your injectors when you have a dry shot. b/c once you go to lean your motors gone. dry kits work really well w/ smaller shots once you go bigger its better to go wet. wet N20 adds fuel and N20 to the motor. this is good for large shots. this allows the engine to have enough fuel to go w/ the N20 so you dont blow your stuff up by going to lean. it really depends on what you want to do to how you want to spray. people like going dry b/c its easy. some like going wet b/c its "safer" than a dry kit. again if im wrong about this let me know

 

so why don't people just use bottles of liquid oxygen (O2 - more o per molecule)? Is it just harder to store?

 

separating h2o? ur water will boil before separating, i don't think u can really achieve this. u know u can stick two electrodes in it and it will separate under a certain voltage, only takes a long time.. but i wouldn't inject water into the cylinder for any reason..

 

It would get way too hot, the nitrogen cools it down.

 

A wet system is more stable because the N20 (nitrous) mixes with the fuel before entering the cylinder. A dry system it enters usually through the cold air intake and only first mixes with the fuel in the cylinder, which can create a separation of the fuel and N20 when compression occurs, giving uneven combustion.

Also, N20 is used (not O2) because it is more stable in its liquid form. Another reason is when the combustion reaction takes place the N2 molecule breaks from the N20 to leave pure oxygen to be combusted. The N2 is partially why the nitrous is so cold.


[Modified by SpoonMan, 3:02 AM 12/17/2002]

 

actually, water injection is a great technique to lower the temperature on a high boost car.... literally, a water injection kit can lower your required octane by as much as 5 points (95 to 90, not 95 to 94.5)

 

But for those of you confused folk out there....you don't literally dump any water in. It's actually injected in the form of very very fine mist. It takes away the heat from the intake air, through evaporation, exactly why we humans perspire.

Jay Kim