Nitrous 101

Nitrous oxide is an engines best friend first developed by the Nazi's in the second world war to make their airplanes faster and more maneuverable, it hasn't changed much since then; nitrous oxide is still a cryogenically frozen liquid that transforms into a gas when released into oxygen. Nitrous can be very safe if used properly, but also dangerous it is taken lightly and not handled with care. Contrary to popular belief nitrous oxide is non-flammable, people get the idea that it can cause engine fires from two different scenarios. On situation is when a person is trying to force too much nitrous in a motor and it back fires along with the fuel that was injected with it, this has to do with the overlap of the valves in the combustion process where there is still an explosion going on inside the combustion chamber and the intake valve happens to be opening; when this happens the fire from the chamber back feeds into the intake plenum where there is atomized fuel vapor and ignites it causing a back fire. The other typical scenarios is on motors that get really hot and some way or another the fuel line in the nitrous kit either leaks or is ruptured from engine damage (such as a backfire, or throwing a rod through the block, or a clutch and flywheel exploding and severing the fuel line).

Nitrous oxide is relatively safe to work with as long as you know the the basics on how to use it and what system is right for your engine. Below is a description of different setups and the pro's and cons of using them with some extra details that you should know.

**Nitrous is a great device of forced induction because it yields the same ration of power increases in horsepower and torque as the engine would normally have. For example if you have an engine that makes 140hp and 140tq on nitrous with a 100hp shot it will most likely yield a result of 240hp+/- and 240tq+/-. It is as if you just have a much larger engine with the same rpm and power band, but just gobs more power.

**Dry nitrous system-Dry nitrous systems utilize one fogger nozzle and one nitrous solenoid. These systems are used for relatively small shots of nitrous, not more that a 75hp increase. These systems are normally referred to as "sneeky pete" nitrous systems and do not use any additional fuel when injecting the nitrous. They only give you a slight advantage and are usually used on relatively stock engines, you'll mostly see them on four bangers and V6 engines.

**Wet nitrous system-These kits contain a fogger nozzle with two incoming ports, one for nitrous oxide and the other for fuel utilizing two separate solenoids. These kits are much safe than dry systems and they are usually used for power increases up to 125-150hp at most. They work well on engines from four cylinders to V10 engines and offer the best value per horsepower available. The only downfall that you have is that in the bigger shots it's possible to run slightly lean (more nitrous than fuel) on the cylinders farthest away from the throttle plate. Both dry and wet single fogger nitrous systems should only be used on fuel injected cars and the nozzle should be placed at least 8-10 inches away from the inlet of the throttle plate. These wet nitrous systems work very well on supercharged and turbocharged vehicles.

**Direct port nitrous system-These nitrous systems are for someone that is really serious about nitrous usage, they are normally intended for fully built motors. These systems have multiple (wet style) fogger nozzles that spray nitrous and fuel into each cylinder on the intake plenum. It is important when designing and installing one of these nitrous systems that you have the fogger nozzle spraying directly into the cylinder head intake port and not against the wall of the inside of the plenum accidentally (this can cause nitrous and fuel pooling which could lead to a backfire. The good thing about these nitrous systems is that the power response is instant with no lag like a dry or wet single fogger nitrous system. The only down fall is that these nitrous systems are very hard on engine internals as well as other drive train components. Good tires is also a strong recommendation because of the instant response of the nitrous on the engine and how quickly the horsepower and torque are accelerated, loosing traction is one of the woes of direct port nitrous systems. These systems are good for 80-250hp+ gains and are normally only used in competition.

**Plate nitrous-This kind of nitrous system is used specifically on old school carb'd cars without fuel injection, it can be either dry or wet in design and since it's used on a V8 (more cylinders, more nitrous) it's typically used for power increase over 100hp.

**Dual stage nitrous-These nitrous systems are two stages (or two individual shots) of nitrous. These systems are used primarily to limit wheel spin when coming off the line and increasing the nitrous shot to a much higher level when either traction has been obtained, mph is increased, rpm is increased, or your into a higher gear. These nitrous systems are mostly seen on automatic transmission vehicles, but can be used on a manual shifting vehicle if properly set up.

**Depending on the amount of nitrous you're using you may need a higher octane fuel this depends on the amount of cylinders, compression ratio, and camshaft profile. So, do some research on the way that others are using the nitrous system you intend to use on your engine.

**The rule of thumb for all nitrous systems is wide open throttle activation after an arming switch has been activated to energize the relay or relays to the solenoids, it is the safest method. Push button nitrous systems only work after they have been armed and the driver has depressed the button on the shifter, these systems can be dangerous if certain fail safes are disregarded such as high rpm cutoff or a full throttle second arming activation micro switch. Basically you want the nitrous to disengage if you accidentally miss shift and go over your engines rev limit. A push button nitrous system is usually only used by a professional driver in a manual shift car with all the fail safes in place: and are somewhat commonly used as a second nitrous stage activation in automatic transmission vehicles.

**One contemporary rule on nitrous systems is to not use a bigger horsepower nitrous shot than the power your engine produces, this rule can only be excluded in certain situations where a motor is completely built around being nitrous dependant such as using aluminum rods, aftermarket cylinder heads, and nitrous designed camshafts.

**You can optimize your nitrous power increases many ways, the most typical ways are: increased compression, nitrous designed camshafts, enlarged port cylinder heads, oversized valves, ported intake plenums and throttle bodies, large diameter headers, and exhaust systems.

**Always keep the nitrous tanks as far away from the driver as possible for safety in case of an accident; the nitrous bottle should always be restrained with the correct bracketry and positioned at a 45 degree angle with the valve facing up, nitrous tanks should never be laid on their sides or inverted for any reason.

**Nitrous bottle warmers and bottle blankets are a necessity when using nitrous in cold temperatures, optimal bottle pressure should remain between 900-1100 psi.

**You should always use spark plugs that are a colder heat range when using nitrous systems. This may take some trial and error, but begin with two heat ranges colder than factory.

**Always begin using your nitrous system with a relatively low horsepower shot so you can get a feel for how it operates and you will be able to listen to the engine carefully to detect any signs of detonation (pinging or pre-ignition).

**You should always retard you're ignition timing when using nitrous. Depending on what shot you're running you may have to retard your timing 5 degrees or more. Look online at nitrous information sites and sites that use nitrous on your particular engine to get a better understanding on how much you should retard your timing.

**One trick to getting more nitrous in your bottle for a better "hit" or more pressure is to put the bottle in your freezer and freeze it before taking it to a shop that fills nitrous bottles. This is a somewhat unknown secret for some reason.

**Always use teflon paste when assembling your nitrous system, do not use teflon tape or any other kind of sealant.

**There are programmable electronic nitrous maximizers on the market today (just thumb through the nitrous section of Summit Racing or Jegs. These controllers allow you to control the amount of nitrous delivered to your engine in correlation to rpm, rpm percentage, throttle position, time, mph, and other various forms of measurement. They do this by electronically controlling the pulse of electricity to the nitrous and fuel solenoids.

**Nitrous will not damage catalytic converters on newer vehicles, however it is recommended that you remove them to get the best free flowing exhaust and horsepower gains.

So do your research and follow these guidelines and you should have good experiences with nitrous, below are some links to nitrous systems and parts as well as information.

http://www.nitrousdirect.com/
http://www.nitrousexpress.com/
http://www.jegs.com/