NOS Question?

Ok....Ive been watching some of these movies on AF and I have seen 2 or 3 videos of cars EXPLODING because they apparently hit the NOS at the wrong time...so tell me....what time are you supposed to spray NOS. How does it work and why does that happen when you spray it at the wrong time? Thx.

Although there is a "correct" time to hit the button the actual event is usually controlled by a micro-switch on the throttle linkage. This switch doesn't turn on until the throttle is depressed to a certain point (usually WOT). What you are seeing when a car explodes is a malfunction in the system. One or more solenoids not activating or a failure to purge the lines before a run.

alright sweet...thx for the info...I was just wondering if it was human error or if it was instrument error....but I guess it can be a mixture of both in some situations! Thx again for the info....and I just realized that I posted this in the wrong forum....so SRY...dont ban me! Later

cars can't "explode" because of nitrous, what you're watching is a bad hollywood movie that likes to stretch the truth and flat out lie. Nitrous isn't even flammable.

Also, call it Nitrous, NOS is a brand or a word for a new item that is out of production (New Old Stock)

Nitrous itself is not flammable-- correct. Thats in a PERFECTLY clean environment. Its an extremely combustable accelerent, It will help oxidize ANYTHING it can. For example, you have to make sure you're running plenty of fuel with nitrous, if you don't the nitrous will start to burn things other than the gas, I.E. your pistons.

oh, and the reason they call it NOS is because of the brand, Nitrous Oxide Systems. Not because of new old stock. (Just like 'Pass me a kleenex' as opposed to 'Pass me a tissue')

I just get miffed when people call it that because nobody used that word until that god awful movie, and NOS was an even more dominant brand back then.

NOS stands for Nitrous Oxide Systems.

Nitrous doesn't burn anything (oxidise anything), the only reason it gives hp gains (besides the cooling effect from depressurizing the gas) is because at around 500 degrees it decomposes into N2 and O2 and the extra O2 (compared to air: air=21% O2 nitrous oxide=33% O2) is what allows you to burn fuel more efficiently

Well whatever it is....it still caused a mustang to EXPLODE when they sprayed the Nitrous into the engine! The video is in the movie section of this forum...I think its called "Death to SVT". When they hit the Nitrous, the intake system exploded in a giant ball of fire! I also saw a movie of this happening with a Corvette and the hood SHOT OFF THE CAR in flames. So whatever happened...the Nitrous was the cause of it and I was wondering how it does this!

From what I understand, when you inject the nitrous you have to time the fuel enrichment perfectly. If you don't it causes an extreme lean condition which causes a backfire. A backfire on nitrous is just a much more violent thing. Sometimes the fuel solenoid fails or the fuel pump doesn't supply enough and kablammo.

often those NO2 explosions you see are due to something called puddling. Most cars intakes are designed to flow a liquid through them. When your injecting a wet kit (gas and N02 are injected through the TB) sometimes the gas sticks to the walls and doesnt go into the engine. After a while it can puddle up, and when the hot engine comes in contact with the puddled up gas, it ignites. Kaboom!

useful info!
http://www.go-fast.org/z28/new_to_nitrous.html

NOS is also laughing gas

Not quite. Nitrous Oxide, used in cars, is N2O. Nitric Oxide, used by dentists and called laughing gas is NO2

Nitrous oxide is an oxygen bearing compound. Its chemical designator is N2O, so we know each nitrous oxygen molecule has two nitrogen atoms and one oxygen atom. Nitrous oxide is sometimes incorrectly known as "NOS". That is an acronym for the company, Nitrous Oxide Systems, which is the largest marketer of nitrous oxide injections system for automotive use.
Injection of nitrous oxide into the combustion chambers of an internal combustion engine as a way to increase power output was discovered by the German air craft industry early in the Second World War. Thousands of German figher and reconassance aircraft were equipped with the so-called "GM-1" system which added nitrous oxide to the intake charge to compensate for reduced air density and less oxygen high altitude. The British Royal Air Force also used aircraft engines with performance enhanced by nitrous oxide. Interestingly, there was no use of nitrous oxide injection by the American military air forces other than very limited experimental use. It is interesting to ask oneself that, if nitrous oxide injection was so dangerous to an engine's reliability, why would so many airplanes have used it?
In this country during 1950s the famed stock car racer Smokey Yunick rediscoverd nitrous oxide injection as one of his many schemes for winning races until discovered and outlawed by NASCAR. Neverthesless, there have been several nitrous oxide cheating scandals in NASCAR over the years and it is probably still used today by the slowest of backmarkers. In the late-70s/early-80s nitrous oxide was "rediscovered" by drag racers and hot rodders.
Today nitrous oxide injection, like many other modifications such as more aggressive camshafts, bigger carburetors, higher compression ratios, more free flowing intake and exhaust systems, can be a pracitical way to more horsepower. And..like any other modification...perhaps even more so because it so easily lends itself to misuse...there can be a reliabity and durability price to pay.
Nitrous oxide is a colorless, non-flammable gas. It has a slightly sweet taste and odor. It is non-toxic and non-irritating and when inhaled in small quantitites can produce mild hysteria and giggling or laughter. This is were the nickname "laughing gas" comes form. When inhaled in pure form it will cause death by asphyxiation because at atmospheric temperatures and pressure, the oxygen in nitrous oxide is not available to the body.
A property of nitrous oxide is that at about 565 degrees F., it breaks down into nitrogen and oxygen. When it is introduced into the intake tract of an internal combustion engine, it is sucked into the combustion chamber and, on the compression stroke, when the charge air temperature reachs 565 deg., a very oxygen-rich mixture results. If we add extra fuel during nitrous oxide injection, the effect is like a super charger or increasing the compression ratio of the engine. Automotive nitrous systems work like the automotive eqivalent of a jet's "afterburner" and is used for short duration extra bursts of power.
Nitrous oxide has this effect because it has a higher percentage of oxygen content than does the air in the atmosphere. Nitrous has 36% oxygen by weight and the atmosphere has 23%. Additionally, nitrous oxide is 50% more dense than air at the same pressure. Thus, a cubic foot of nitrous oxide contains 2.3 times as much oxygen as a cubic foot of air. Just do a bit of math in your head and you can see if we substitute some nitrous oxide for some of the air going into an engine than add the appropriate amount of additional fuel, the engine is going to put out more power.
Simply stated, nitrous oxide injection is very much like a supercharger or a compression ratio increase in that, during combustion, it can dramatically increase the dynamic cylinder pressure in the engine.
Of course, when we significantly increase the cylinder pressure in the engine, we also increase the engine's tendancy to detonate. This is why almost all nitrous motors require retarded spark timing during nitrous oxide operation. The cylinder pressure increase is also why, when misused or improperly installed, operation with nitrous causes problems with head gasket seal and failures of the rings or pistons. I should point out that any number of things that put an engine into severe detonation, such as too much boost from a supercharger, low octane fuel, excessive compression ratio or overly lean air-fuel ratio will also cause the same kinds of damage.
Another challenge with a nitrous oxide system is getting the delivery of nitrous oxide and additinonal fuel at the correct proportions. If you feed nitrous to the engine without enough extra fuel, the lean air/nitrous to fuel mixture will make the detonation problem even worse. Combustion temperatures will skyrocket and catistropic failure is certain to occur. If the proportion is such that too much fuel is delivered, the power advantage degrades rapidly.
As you can see, nitrous oxide is like any other power increasing modification in that, when used wisely and installed properly, it works well. Then used foolishy or installed incorectly it can significantly reduced the reliability/durability of your engine.
Small doses of nitrous oxide can be used in stock engines to gain 25-35% more power. In my opinion, any more than nitrous than that with a stock engine compromises durability too much. This is not only true of nitrous but any modification. Take a stock 82 or 84 engine, up the horsepower to 300hp and do nothing to improve durability and your engine will eventually suffer. Once you pass the 35% power increase mark with nitrous oxide you need to look at things like forged pistons, better connectiing rods, better bearings, etc.
Nitrous oxide is also a great value on a dollar-per-unit-power increase when installed and operated properly. The downside, of course, is the fun ends quiclky. The power boost lasts as long as the nitrous. The average bottle is a 20 pounder and with a street V8 that might be worth 20 seconds of use.
So, nitrous oxide is not the instant-engine-failure many people think it is. When used properly and when dispensed by a properly designed and installed system nitrous oxide can be responsible for some phenominal increases in power.