There seems to be an increasing amount of discussion about nitrous
. I figured since I have been around it for a while, I should post up information about it.
So here it is.
What is nitrous?
Nitrous, Nitrous Oxide. N2O, Nitro, Laughing Gas, Giggle Juice, etc .. are all the same thing.
It's chemical sybmol is N2O. That is 2 nitrogen atoms and 1 oxygen atom.
It is a colorless, nonflamable gas at room temperature, automotive nitrous has sulfur added to discourage from inhalant abuse.
But what about NOS??
NOS is a company, Nitrous Oxide Systems. It's basically the same as saying Kleenex instead of tissue. Don't ask about NOS unless you are asking about one of their prodcuts.
What is nitrous used for?
Nitrous is used as an anaesthetic (Laughing gas) or as an oxidizer.
For engines it is an oxidizer. Basically, a power adder when used properly.
How does it work in an engine?
An engine requires three things to create power. Fuel, oxygen and ignition.
When nitrous is heated and compressed to around 570F or 300C, the nitrogen and oxygen atoms will split. So during combustion, you will have more oxygen inside the cylinders. Since you have more oxygen, you can add more fuel to create a bigger bang, thus more power. Also, on top of more oxygen, when nitrous vaporizes, it provides a signifcant cooling effect on the intake air, create more dense air, further adding more power. Remember, adding more power creates more internal heat.
Is nitrous flamable?
No, not really. As mentioned, it is an oxidizer. When pressurized and heated, the atoms will split thus creating more oxygen for an existing fire. However, if you spray nitrous at an open flame, the nitrous will actually extingush the flame.
But I watched Fast and Furious and nitrous made the Eclipse explode in a blue/green fireball!!
It's called special effects. It's a movie. It's not real. Unless it is, then it would just be a glitch in the matrix.
Can nitrous explode?
Inside a nitrous tank there is a burst/rupture disk. What it does is release pressure when the tank becomes over pressurized. Typically when these fail, the gas will just spray out with an intensity equal to the bottle pressure.
However, there have been times when a rupture disk was improperly installed. If this is the case, the gas will continue to expand until the tank fails, resulting in basically a bomb.
This Mustang supposedly had an improperly installed rupture disk, with a full tank of nitrous sitting out in the Texas
sun, as you can see, it didn't end well for the car. A properly installed rupture disk would have prevented this.
Nitrous Oxide Tank Explodes Inside Vehicle in Midland - KWES NewsWest 9 / Midland, Odessa, Big Spring, TX: newswest9.com |
There are also blow by/down tubes that should be installed. It will vent nitrous outside of the car.
Will nitrous destroy my engine??
If used improperly, it can destroy your engine, just like any other power adder.
As mentioned, nitrous is an oxidizer. So adding more oxygen to an engine will require more fuel. If you don't have the extra fuel, your car will run extremely lean and once this happens, the temperatures will become incredibly hot inside the cylinder. Hot enough to melt the spark plug end, hot enough to cause pre-ignition and then in a very short time (a few seconds), your engine will be essentially, toasted.
Another thing with nitrous is that it is an immediate power adder. Superchargers and turbos built boost, nitrous is immediate. This sudden jump in power puts extra stress on the everything but mainly the pistons, rings and rods. The cranks in most cars are beefy enough to handle this with no issues.
Proper tuning, like all other power adders is one of the most important factors in using it. Mail order tunes can likely get you dialed in safely with a 100 shot or less. For more than that, a custom dyno tune will be needed.
Another thing that can happen with nitrous is fuel puddling in the intake. If this happens and there is a small backfire, the upper intake will likely blow apart. Most videos you see online of nitrous cars blowing up is caused by this. It's important to note that the fuel is the cause of the explosion and not the nitrous.
Is nitrous legal????
It gets tricky.
Nitrous for a car is not illegal in any state or territory in the United States.
In some states, it is illegal to have it connected to the line. Others, it can't be in the passenger compartment and finally, in some states, the
disconnected parts cannot be reconnected from the driver or passenger seats. Otherwise it's perfectly legal.
Also, some states do not allow more than 10lb bottles without a hazmat sticker and endorsement.
Other than that, you are good to go.
So mount it in the trunk and use a remote bottle opener.. problem solved. If you get pulled over and the nitrous is connected and the tank is filled, you likely have bigger things to worry about, such as why the police are searching your vehicle in the first place.
What type of nitrous setup should I go with?
There are two types of nitrous setups. You have a dry shot and a wet shot.
Dry nitrous systems are just spraying nitrous, usually past the MAF and letting the car figure out how much fuel to add. These systems are usually good for up to 50-75 shots depending on application. A dry system will place more load on the entire fuel system (fuel pump, injectors, etc..), so adjust accordingly.
Wet nitrous systems will spray nitrous and fuel together into the intake. Usually spraying either into the intake tract through a single nozzle or using a plate and spraying into the intake behind the throttle body. This will add stress to the fuel pump. Again, adjust accordingly.
All kits should come with jets for nitrous, and fuel if it's a wet kit.
There are also direct port nitrous setups, if you are interested in those, you should already be familiar with nitrous.
What other things do I need for a nitrous setup??
In my opinion, the absolutely essential things needed are a window switch, purge kit, nitrous pressure gauge, bottle heater, a good wideband or UEGO, blow down tube (have to have this for the track) and a fuel pressure safety switch.
What do all of those do??
Window switch - sets the RPM at which nitrous will spray under WOT conditions. Typically you want to start spraying around 3,500 rpm and spray up to 500 -
1,000 rpm before your rev limiter. Example, in my Z28, I have it set for 3,500 - 6,500. My rev limiter is set at 7,200 rpm. Once I pull the trigger and install this on my 3.7, I will run the same setup - 3,500 - 6,500.
Purge kit - This is a must have. This will purge the nitrous line of air before use.
Nitrous pressure gauge - tells you the bottle PSI. Generally keeping the bottle between 950 - 1050 psi is optimal. Drop below 950 and you will not be getting the shot you expect, go above 1050 and you may get too much nitrous and not enough fuel.
Bottle heater - This will properly warm the bottle up in order to achieve the appropriate bottle presure. Depending on conditions, this can take a few minutes up to 30 minutes.
Wideband or UEGO - This allows you to monitor the A/F ratio of your engine.
Blow down tube - this will allow nitrous to exit outside of the car if there is an issue with the bottle over-pressurizing.
Fuel Pressure Safety Switch (FPSS) - This will automatically shut off the nitrous if the fuel pressure drops below what it is set at.
How much does it cost?
The bare systems can be purchased from around $500 and can go up to over $2000. It all depends on what you want. On average, most people will have around $1200 - $1700 invested in a new nitrous setup. That does not include tuning by the way.
Nitrous refills are can vary greatly by region. Typically, $3 - $5 per lb is normal. So $30 - $50 for a 10 lb refill. My last nitrous fill was $37 for 11 lbs. He overfilled.
Depending on the size of the nitrous shot, you may need colder spark plugs. Typically for every 75 horsepower in nitrous, you should drop down to a one step colder plug. So for a 75 shot, you drop down 1 step colder. For a 150 shot, you go 2 steps colder. Also, do not use platinum plugs. Copper or Iridium only.
A remote bottle opener can be used if you don't want to open the nitrous valve manually.
Progressive controller. This will allow for the nitrous to be slowly added over time. Say you are spraying a 150 shot, with a progressive controller, the shot could start out at a 50 shot and work its way up over a predetermined time to the full 150. This can aid in traction and the longevity of your engine as it will not receive the full shot instantly.
If anyone has anything to add, please do.