Nitrous bottle basics

[charliebravo77]

Q: How long will the bottle last?
A: This largely depends on the type of nitrous kit and jetting used. For example, a 125 HP Power Shot kit with a standard 10 lb. capacity bottle will usually offer up to 7 to 10 full quarter-mile passes. For power levels of 250 HP, 3 to 5 full quarter-mile passes may be expected. If nitrous is only used in 2nd and 3rd gears, the number of runs will be more.


NOS bases that on their test example - a mid size car weighing in at 3,300 - 3,500 pounds with a ~350ci motor. If your car is heavier and the motor is bigger, the results may vary.

[mySStery_machine]

Anyone else can post some basics for nitrous here. I would like the first few posts mainly technical for search purposes. Thanks!

[nwavetteman]

Nitrous safety for wet kits!!!!


A lot of people are scared of running nitrous because of explosions and rumor of nitrous jsut tearing apart your engine. Truth is nitrous can be run VERY safely. If you do it incorrectly the results can be terrible though.


here are some basic things you should have on a wet kit;
A bottle warmer
blow down tube
purge
fuel pressure safety switch
WOT switch
and a window switch


A bottle warmer is needed to get the bottle up to operrating temps. I like my bottle to be around 1050psi. This allows the system to function properly, and if you always run at the same PSI the results will be more consistent.

A purge will clear the lines of unwanted air. This also helps for the system to run more consistent.

Fuel pressure safety switch will shut your nitrous system down in the event of fuel pressure loss. Since a wet kit uses fuel right from your main fuel system and the car will go extremely lean (and probably make one of the BANGS! everyone is so worried about) the system is shut down.

WOT switch is needed for 2 reasons... !, no buttons to press to make you stop paying attention to your run and more important things, and 2 you only want to fire nitrous at WOT so you again don't go lean.

A window switch is needed to activate the nitrous a XXXXrpm's. If you activate a wet kit at too low of an RPM fuel will usually puddle inside the intake and cause quite a bang that will do some severe damage. General rule of thumb is NEVER fire your wet kit below 3k rpms.


there is a little nitrous safety for wet kits :)

[DocBowtie]

Whats the blow down tube for? Lets make this a Q&A about Nitrous ;)

[Euclid]

i beleive the blow down tube is a safety measure just incase you overfill or overheat the bottle.. when the pressure builds up it releases some of it into the air.. the tube is routed outside the car.. But correct me if im wrong..


Here's and article from HRM bout nitrous basics.. Very basic info..

What It Does

Nitrous oxide is a gaseous mixture of two parts nitrogen and one part oxygen (N2O). The gas helps make power in two ways. While nonflammable, its single oxygen molecule is used as an oxidizer to allow more fuel to be burned to create more heat and pressure during the combustion process. That is why nitrous must be accompanied with additional fuel. If additional fuel is not added, the engine will run lean, creating excessive combustion temperatures that will cause detonation and, eventually, severely damage the engine.

Nitrous oxide is stored at 800 to 1000 psi as a liquid, but injecting it into an engine converts the liquid nitrous to a gaseous state. That conversion reduces overall inlet-air temperature by absorbing heat, contributing to increased power by making the air/fuel mixture more dense. Inlet-air temperatures can drop by as much as 60 to 75 degrees Fahrenheit during the process. That’s important when you consider that power is increased by one percent for every 10-degree Fahrenheit drop in inlet-air temperature.

During combustion, at a temperature of 575 degrees Fahrenheit in the combustion chamber, oxygen separates from the nitrogen molecules and is available to help burn additional fuel. The nitrogen molecules act as a buffer to combustion, slowing the burning process to a more manageable rate as opposed to a violent explosion that is extremely hard on pistons, rods and crankshafts. That’s why nitrous oxide is used as opposed to pure oxygen.

How Nitrous Systems Work

A crucial element of nitrous-oxide injection is the input of additional fuel. Nitrous companies eliminate mixture guesswork by offering matched systems that mate known nitrous levels with safe amounts of gasoline. That’s why, at least for first-time nitrous users, the best bet is to use a matched system from one of the major manufacturers rather than a cobbled-up system.

To give you an idea of how a nitrous system works, take a look at the accompanying illustration. The nitrous tank stores the pressurized liquid nitrous until it’s ready for use. When the bottle’s valve is opened, pressurized nitrous exits on the upstream side of the nitrous solenoid. A matching gasoline solenoid is tapped into the engine’s fuel-delivery system and supplies the necessary fuel. In a plate-type system, both the fuel and the nitrous are introduced into the engine via a plate with small orifices drilled into spray bars, one for nitrous and one for fuel. For activation, most nitrous systems combine an arming switch, which merely powers the system, with a second momentary switch, which is usually a button placed on the shifter handle. The momentary switch completes the electrical circuit to open both solenoids. That introduces the combination of nitrous and fuel into the engine—and then it’s time to hang on!

What Can Happen

The foremost concern of any hot rodder is whether nitrous might be harmful to his engine. If installed and tuned properly for a particular application, nitrous will not harm an engine—although burned pistons and engine explosions are the reality checks that do play a part in the use of nitrous oxide. The gas makes serious cylinder pressure, however, and if enough cylinder pressure is added to an otherwise stock engine, it will fail. But basic 75- to 150hp kits are compatible with even stock engines and don’t present a danger to engine life if used properly.

That’s not to say that nitrous won’t hurt an engine if you decide to ignore the rules. Nitrous can bend connecting rods if triggered at too low an rpm, especially if the car is in high gear, since the additional power is more than the internal components can handle. Nitrous Oxide Systems (NOS) suggests not hitting the nitrous below 2500 rpm for the typical plate system. In addition, too little fuel pressure can also create a lean situation that has spit out many a head gasket or worse. Ignition timing also plays an important part in nitrous tuning. Timing should be retarded according to the manufacturer’s recommendations. We know of one heavily nitroused EFI engine that runs with 0 (zero) ignition lead to keep the engine out of detonation.

But don’t let these warnings intimidate you. Nitrous has been proven to be a safe, reliable and powerful addition to the hot rodder’s horsepower arsenal. Like any other power producer, though, it must be treated with the respect it deserves. And the best part is that there’s a system designed just for what you want.

[mySStery_machine]

Good posts, keep the information coming!

[nwavetteman]

yeah and I beleive if something goes really wrong with the nitrous kit the blow down blows ALL the leaking gasses outside of the car so you don't get "happy"

[marianne125]

Yayay!!!! :grin2:

[Cyamaha2007]

i was told blow down tubes were incase you left your bottle heater on. the blow down valve lets go at 3000 psi or so and in some odd ball cases they dont let go and the bottle explodes demolishing the car garage and things parked next to your car. my idea to solve this problem is to just only leave the lead to the heater swich energized when the ignition is in the run position there for making it imposible to blow the tank unless you leave the keys in your car. i hope this made sense i just had my wisdom teeth out and im a little:fluffy:

[White96Z28]

i was told blow down tubes were incase you left your bottle heater on. the blow down valve lets go at 3000 psi or so and in some odd ball cases they dont let go and the bottle explodes demolishing the car garage and things parked next to your car. my idea to solve this problem is to just only leave the lead to the heater swich energized when the ignition is in the run position there for making it imposible to blow the tank unless you leave the keys in your car. i hope this made sense i just had my wisdom teeth out and im a little:fluffy:

Using a switched lead is a great idea, unless you're stuck parked in the staging lanes for more than an hour between runs and want to keep your bottle pressure consistant... I guess it would work great if your local track isn't all that busy, or you don't spend much time there. As for the blow down tube, the bottle heater isn't the only way to exceed the pressure limit of your system. A blow down tube is a good idea for any set up. It's one of those things like a driveshaft safety loop, nobody likes having to install one until the DS goes...