Ok, so lately there has been a lot of talk about nitrous oxide / N20. Lots of people seem to have trouble understanding the system and idea behind it, so I decided that perhaps a bit more knowledge available to everyone would be helpful.
I am not a chemistry major, nor have I actually ever ran a N2O system, but I have been very fascinated with the idea for quite some time now. Hopefully I can help some of you out with it.

To start out for the real newbs, NOS is simply the holley brand name Nitous Oxide Systems. Ever since fast and the furious came out, there is a new breed of wanna-be speedsters out there and lots of the time I see themselves getting lumped into that category when they call nitrous oxide NOS. IMO you might as well just call it your turbo booster, haha.
Anyways before we get too much into the systems that are available and myths associated with them, I want to start by explaining a bit of the chemistry and properties of N2O.

Nitrogen is an inert, not very usefull gas which constitutes about 80% of the earths atmosphere. The other 20% (give or take a bit for argon, etc etc) is oxygen. This is the natural oxidizer for the fuels combustion inside the engine.
But, guess what?
Nitrous Oxide (N2O) is composed of 2 nitrogen atoms bound with an oxygen atom, the same elements used as the fuels oxidant naturally! They just found a better way to apply them. what a co-incidance!

So, now your probably wondering what the advantages of this whole process are, and its prety simple actually. Whether you use a turbo, supercharger, or nitrous the goal is to get as much oxygen into the engine as you can, in turn also putting just the right amount of gas in as well. The more fuel and oxygen the larger the explosion. Fuel generally isnt the difficult part to get in, the oxygen is considering the ratio is quite easy on the fuel.
Turbochargers and superchargers mechanically add more air in the form of pressure. This ends up causing more oxygen to be delivered to the combustion chamber. Nitrous oxide does the same thing, however in a chemical reaction. The nice part about nitrous oxide is that it is stored in a pressurized liquid form, and when it flows into the intake, it evaporates which will drastically reduce intake temperatures. The pressure of the gas also gives it a mechanical like effect, pressurizing the combustion chamber alike a turbo or supercharger.
Theres a quick run down of the ways to deliver more oxygen than the atmosphere naturally can.

Now for the myths:
Often people claim that N2O isnt safe for your engine. If you just think about it, its just as safe as a turbo or supercharger because they do the same thing..Add more oxygen.
Either option takes some fine tuning in the fuel area, but none is either safer or more dangerous.

In this respect I think nitrous is a fair contender as a safe power adder. You just cant overdo it (remember, this applies to turbos too).
Just as reliable as anything, IMO.

Also, people expect nitrous oxide to be so dangerous and incredibly flammable. This couldnt be farther from the truth. Aside from the fact that any pressurized cylinder is dangerous, nitrous oxide is nothing without a fuel source. As I mentioned above, it just allows more fuel to be added for greater combustion.

Nitrous oxide Is the same as the old laughing gas they would give you in hospitals. yup, laughing gas. Automotive grade N2O does have a posionous additive added to discourage it from being used as a drug. haha.

Now I hope this has been a helpfull explanation of the basics, if anyone has anything to add please do. Now that we understand how it works, lets move on to the different systems, applications and choices you have for kits. If you dont understand, read it again or research. People really need to understand the basics before they look at the different setups.


The largest difference in N2O systems is if it is nitrous only (dry) or nitrous and fuel (wet).

Just so everyone is on the same page I will go over terminology of the systems parts too.
Every system will have these:
NITROUS OXIDE TANK- A removable tank that will hold the liquid N2O, usually in the trunk or rear of the vehicle. The tank has a shutoff valve for the Nitrous flow.
REMOTE BOTTLE OPENER- people sometimes install a remote valve for the nitrous tank, just so they can be lazy and turn on the bottles flow from their seat.
NITROUS LINE- Feed line from the nitrous bottle to the solenoid.
SOLENOID- small electronically actuated valve under the hood as near to the fogger as possible. Controls when the nitrous/ nitrous and fuel is injected into the engine, which is controlled by a button in the vehicle and the throttle switch.
DISTRIBUTION BLOCK- If you have more than one fogger, the line out of the solenoid will go here to be distributed to the individual foggers.
FOGGER(S)- the nozzle/orifice that injects the nitrous and fuel into the engine. Sometimes a "plate" system is used to inject the nitrous (like a fogger but different, bolts onto the intake).
THROTTLE ACTIVATION SWITCH- This switch lets the nitrous system know when the throttle plates are open all the way. Makes sure that there is sufficient airflow available to the engine, and that the nitrous activation was not accidental.
PURGE VALVE- Occasionally people will install a purge valve to their nitrous system. This simply allows any residual pressurized air or anything in the nitrous line from the bottle to the solenoid to be expelled prior to using the nitrous. It just vents to the atmosphere, you may have seen a car purge their lines before it is accompanied by a large plume of nitrous and a large pssssssshhhhh sound usually around the engine area. people tend to overexcitedly use it to show off that they have nitrous, lol.


A dry kit should only ever be used on a car with fuel injection, set up to add more fuel when the nitrous is injected. Although if set up properly this setup should be safe, I dont like the idea of expecting the fuel system to integrate properly with the nitrous system. Too many variables, why not leave it all to one system....

The only benefit of a dry kit is that the nitrous isnt accompanied by gas, and can be installed more leniently, allowing the nitrous to take a path you wouldnt want gas to take (cone filter N2O kit).

The wet kit. The best choice I would say, Not only does it inject nitrous into the engine, it also adds the corresponding amount of gas as well. This would appear to be the safest setup, because the fuel and the nitrous are being controlled by the same system, no integration needed.

There are many types of both kits, some mount on cone air filters, some in the air intake tube, some bolt below the carburator, and some on the throttle body on FI vehicles. Some get drilled into the lowest part of the intake, or even fit on over fuel injectors.

Anything mounted outside of the throttle body or carburator is definately a dry system. Good in some cases, but not for us. Wet systems (good, good) are generally below the throttle plates, or carburator for safety reasons (so the least amount of combustible gas is outside the engine). Dry kits can still install below the carb / tb just so everyone is aware...
For consistancy, I would suggest nothing but wet foggers plumbed into the intake. 1+ per rotor/cylinder. This will insure that the flow is evenly dispursed to the combustion chambers and that everything is as safe as possible.
An A/F meter never hurts to keep an eye on your exhaust!

Now when it comes to the different wet kits, there are kits designed for fuel injection vehicles, which need 60+ PSI at the solenoid. Then there are also kits designed for carburated applications which only need about 5 PSI. There is no need to have to buy a whole new fuel system if your current carb setup will suffice for flow. Just keep that in mind.

As for safe HP settings, I will leave that upto experienced people who have used such systems before, feel free to chime in. However hopefully this writeup will help people understand that nitrous oxide systems are a viable alternative for turbos/superchargers, and really dont have a much different effect in the end.

I hope I havent forgotten anything, If I have feel free to add.
Thanks for reading I hope I have been helpfull!

 

Nice writeup. I think the reason N20 has such a bad reputation is that it is so easy to undercompensate for your oxidizer and end up running super-lean. In reality, it isn't much different than a super or a turbo, as you say, but mechanically driven compressors are by nature more predictable (at least when functioning properly). I've only ever seen two cars where I could say it was definitely the nitrous system that was responsible for engine damage, and in both cases, it was a poorly designed system that resulted in an extremely lean mixture and raised cylinder temps dramatically. It's also pretty easy to overboost, even while maintaining appropriate A/F ratio, simply because volumetric gaseous expansion is by nature less predictable than mechanical compression.

 

this is great thanks!

 

Other then this, nice writeup.

 

Archive x9999

Revhed if you have another theory then explain it so we can get this thread archived!

 

Revhed, Im gonna have to agree with you on that one. It did come out somewhat unclear.

I just wanted to touch on the fact that your engine doesnt suck the nitrous in like it would gas from a carburator, It is injected creating higher than atmospheric pressure in the intake - forcing its way into the engine like a turbo or supercharger.

I felt it was important to make note of this because in any of these cases, its easy to exceed the limits of your engine from overboosting in turbo+supercharged applications which is equivalent to running too large a shot of nitrous in this case.

I just really want people to understand the concept, and respect the incredible potential of N2O.

Thanks for pointing that out. Hopefully this clears things up!

 

if anything I would think you would suffer from the opposite for a split second... the NO2 is very cold and dense, hense the power gain... once it is released in the intake tract it has the effect of condensing the rest of the charge due to the tempature diff. major lean out problems yes, hence the wet system.... pressurized no.

kenn

 

I have a little demonstration I show my friends when they say this, I'll take an almost empty tank of N2O and spray a lit cigarette with it. Makes the cig burn like a sparkler, but thats it. Also a great way to explain the difference between an oxidizer and a fuel. Great write up, hopefully more and more poeple will read it

 

When N2O is injected into the intake it is a liquid. The low boiling point of nitrous oxide is the important factor here, because it causes the liquid to evaporate into a gas at atmospheric pressure.
This reaction is what cools the intake charge and makes the the air more dense. If it was simply the air in the intake being cooled, then yes the volume would decrease, but since N2O is being introduced in a pressurized form, I would assume that even considering the cooling effect of the chemical reaction, the intake would still be pressurized to some degree.

The cooler dense gas that enters the combustion chamber is going to increase volumetric efficiency of your engine and in turn power,
but the real magic is that our atmosphere contains only about 20% oxygen as I stated earlier, this would mean that the maximum amount of oxygen available to the engine is 20% of the gasses volume. When N2O breaks down in your engine you will have around 30% oxygen available for combustion.

I feel my theory of the combustion chamber being pressurized is accurate because if there is no added pressure to the intake charge, you wouldnt see much more than a 50% increase in power due to having 50% more oxygen. Before anyone says that Im not taking the increased volumetric efficiency due to the colder intake charge into account, I am..but it probably wouldnt add much to the 50% increase figure listed above.

My question for you guys is: when 200%+ horsepower gains are possible, is 50% more oxygen and a colder intake charge going to account for that gain?

 

Another thing to mention: if your nitrous system is built correctly, then the in-cylinder (or trochoid) effects will indeed be similar enough to those of a supercharger to call that a good corollary (the cooling/pressurizing effect is somewhat negligable - what you're really after is the additional oxygen). However, one main difference between these two methods of feeding your engine additional air is where it comes from. A supercharger compresses atmospheric air and thus forces more into your engine. With nitrous, someone else has filled a cylinder with compressed gas for you, which you then use. The biggest thing nitrous has going for it over turbo/super is it's cost factor, but that margin gets slimmer and slimmer each time you refill your N20 tank. Is it better to buy milk every few days, or just buy a cow?

 

isn't this my write up just rewritten with smaller words and more vagueness. words. Why yes, yes it is.

 

For those looking for it here it is

The Nitrous Thread Reply with quote

Hearing alot of people asking questions about nitrous use on different forums so hear is a quickie I made up.

First you must know what Nitrous does in the combustion process, and how it affects AFRs and EGTs.

A good link to view
http://auto.howstuffworks.com/question259.htm

http://auto.howstuffworks.com/framed...ib/nitrous.htm

N0 is an oxidizer, which means it adds more air to the combustion chamberand cools intake temps. The cooler the air the more dense it is, the more dense it is the more you can put into the combustion chamber. But it also makes you engine run leaner, so there are other things that need to be done to ensure you dont burn up valves, pistons, or blow the welds on your intake j/k Laughing

Also movies like the slow and the courious have made the use of nitrous seem unsafe, unaffordable and damaging to your engine. But one must understand that adding any significant amount of power will lower the life of your engine. And the more and more power you add the shorter the lifespan of the engine. But lets not forget that if you have ever been to a dentist that laughing gas is just medical grade N0.

Why Nitrous over a turbo setup.

For the most part a nitrous system has a cheaper startup cost, its cheap to get a bottle refilled, the kits are upgrade able for more power and with proper tuning can create awsome power.

Dry kits are your cheapest way of getting on the sqeeze. This kit injects nitrous directly into your intake without a mixture of fuel added to it. These kits are fine for about 50hp increase, are easy to install. But atleast go out and buy a cheap narrow band AFR gauge with this setup. To much nitrous and you could start to detonate, which could eventually destroy your engine. Remember a proper working setup that produces less power for longer, is cheaper than running at max power for a little bit then having to rebuild. I would also recomend a SAFC(apexi) to control the amount of fuel being injected into your engine again its cheap insurance.

Next is you wet kits. They inject nitrous and fuel at the same time into the intake and makes more power than the dry kit, and they are alot safer on the motor. But again dont be cheap. That extra fuel is good but it could also stress ot your stock fuel pump. So go ahead and put a fuel pump and a narrow band, and a SAFC on your budget when buying the kit.

Direct port or fogger is up now. Mush like the wet kit but now there are the same number of nozzels as there are cylinders(or more depending on how big and bad you want to be). This system also injects fuel at the same time as nitrous, but instead of having one nozzle in the intake pipe, or on the intake mani, each nozzle is placed at the port opening facing the valve. As far as the fuel and electronics are concerned on this kit I would spring the extra cash on a wideband, bigger fuel pump, ou could run a piggy back with bigger injectors and try and tune with it but if you already put down this much money go ahead and at least get a cheaper standalone. Again safer is more expensive to start but pays for itself 1000xs over.

Direct injection is next. Kits that are direct injection are nitrous nozzles that go on the end of a fuel injector. This kit directly inject nitrous into the cumbustion chamber. But again the same safty measures are here agian, but I would also recomend going full standalone, bigger injectors, and a wideband instead of narrowband. These kits offer the most power at the greatest cost. So do it right and do it the first time.

Again one of the biggest mistakes about using a nitrous kit is not doing supporting mods. Also tuning helps in building more power safly in the engine and fuel systems capablities. The safer the setup the longer the motor lasts, and that means the more fun you get to have. One item I did not mention above was the addition of a boost gauge. This is to keep an eye on the intake manifold pressure, and again it is just for insurance.

Also another way people are ruining motors is because they do not follow the instilation instruction.

DRILLING AND TAPPING THE INTAKE MANIFOLD WHILE IT IS ON THE CAR IS A BAD IDES DO NOT DO IT. Intake gaskets are cheap enough go out nd buy one remove the intake and then drill and tap you holes for the nozzles. Then make sure that all of the shavings are out of the manifold before you put it back on. It only takes one metal shaving to ruin a motor.

Also make sure you install your bottle corectly bolt it down securly and with the correct bracket. All of the bottles syphin from the bottom of the tank. And having the tank correctly installed insures you are getting the most out of your fill.

When you run your lines, run them correctly. Make sure they are secured correctly not draging the ground if you run them externally, and if you run them inside make sure they are not going to get tangled up in your feet when driving. And like all wiring use gromets when going through the firewall.

If you want to you can spend a lil bit more money and make your system alot better. You first upgrade should be a bottle warmer, this will improve your consistantcy(sp), next I would say would be a remote bottle opener, nothing is worse than going through the fumble ruitine trying to get into your trunk and open your bottle.

Note on purging your system. This is so that you know that there isnt any air in your lines. You dont have to go all imma waste my fill on a 10sec showoff. Ususally purging takes less than 2 seconds. Also where your purge lines is up to you. The center of the windshield is a good place to run your line, that or a wheel well. I have run my line strait down the firewall and out the bottom of the car for a less obvious purge.

As far as nitrous being cheating. It isnt, it is a type of forced induction and just because you didnt spend 10k for the extra power dosnt mean it is cheating. There is really no way to hide a system. Bottles are big(except for the sneaky pete) there are various valves , switches, nozzles lines. If they cannot figure out your a running the juice after looking at your car before a race then either they are really stupid, or totally have no understanding of the system.

I thought about hiding a couple setups, but in the end its not really worth the effort. I keep all my racing on the track nowadays, and just having it visible and done correctly is way easier going through the visual inspecion on race day.

But then again I have seen some great hidden setups. Bottle was in the back in the spare tire well that was modified for it to fit, noids were in the glove box nozzles were on the bottom of the intake and switch was wired up as the AM FM button on the stereo.

If you are out racing on the streets though and money is involed, I have seen people get there asses beat for not telling anyone they were on the bottle. That IMO is cheating, and is the reason most people shun upon it.

I know I said ealier that if you were to retarded to notice it its your fault. But if its a closed hood race and you simply state whats under it you should tell the truth.

Hmm I forgot Direct port, but got direct injection, how did I mess that one up.

As far as recomending a kit, it really depends on what you want to do with the car much like choosing a turbo. I prefer the wet kits because its an extra safe gaurd if tuned right and not getting over zealous.

Info on stages:

This is something I have not dealt to much with myself, and I do not know many that do so Ill try to explain it the best I can. If I am wrong please do correct me this is something I have been wanting to learn about.

A dual stage set up usually consists of 2 wet kits, or 2 direct port, or a direct injection system with one of the other system, or any combo of the three. And depending on how much nitrous and fuel you are going to throw at that bad boy you may need 2 fuel pumps, on for the car, and one for the nitrous systems.

The system basically works like this. You have a smaller shot in the beginning say a 75 wet as your first stage. Well you find that when racing a certain oponent that this shot is not big enough, you reach over flick a switch to arm, turn on the secondary fuel pump, and prime the secondary system say a 125 direct port. You lay down on you second stage without lifting you first, this in turn gives you the equvilant of a 200 shot. Thats about the best way I can explain that.

This system also takes the most tuning to get right. A wideband. standalone, fuel system upgrade, ignition upgrade, and all the other supporting systems, not to mention dyno time, and a ton of tuning to get right. This is one you dont want to skimp on, staged systems can reach up into the 500hp or above range at the push of a button.

I am sorry I dont have any more info on this Ill try googling it later today.


OK we have been messing around with some juice so this is just a lil update for the D16.

I am not sure if it because of a bad sensor or just being over zealous, but I do not recomend going over a 50hp shot on stock injectors. From below 4k the A/F was pretty good, but as soon as we started pushing the car upward in the RPMs we hit a major snag. The motor completly leaned out from 4.5k on. WE could have continued to push the motor to redline, but from what our a/f gauge was reading it was gonna go.

This was on a 75shot, but your results may vary some.

All this is directly form one of my stickies on another forum.

 

Nice, another Nitrous Oxide thread for the archives...

Jon