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FAQ Nitrous info to be shared!



Perhaps this can be made as a sticky at the top of the threads or something like it. I found this on a local racing site I am on. Maybe read it over and revise it and put it as an important sticky on the top. It helped me a little:
It might help people like myself that are new to modding cars!

First, here are some links to a lot of really good information. The site that isn't NX is very informative, however there are a couple of things that I do not agree with, like the jetting estimations for hp (I think he is referring to NOS jetting so be forewarned about the figures that he has if you are using some other brand of system).


To get 200hp and 250hp from the standard NX Ford EFI single nozzle system here is I would recommend getting:
pn 10124- -4 line to replace the -3 line that comes in the system
Correct jetting for your fuel pressure at WOT
Upgrade the fuel pump (I would recommend a Walbro 255 or Aeromotive equivalent)

Here are some Q's and A's for you. I basically just pieced all of this together from myself and other people, but I have read it entirely so don't worry, haha.

Q: Will Nitrous affect engine reliability?
A: The key is choosing the correct H.P. for a given application. A kit that uses the correct factory calibration does not usually cause increased wear. As the energy released in the cylinder increases so do the loads on the various components that must handle them. If the load increases exceed the ability of the components to handle them, added wear takes place. Nitrous kits are designed for use on demand and only at wide open throttle. Nitrous can be extremely advantageous in that it is only used when you want it, not all the time. Most Nitrous kits are designed for maximum power with reliability for a given application.

Q: Can I simply bolt a nitrous kit onto my stock engine?
A: Yes. Most manufactureres make systems for virtually any stock engine application. The key is to choose the correct kit for a given application; i.e., 4 cyl. engines normally allow an extra 35-75 HP, 6 cyl. engines usually work great between 75-100 extra HP, small block V8's can typically accept up to 150 extra HP, and big block V8's might accept from 150-200 extra HP. These suggested ranges provide maximum reliability from most stock engines using cast pistons and cast crank with few or no engine modifications.

Q: What are some of the general rules for even higher HP gains?
A: Generally, forged aluminum pistons are one of best modifications you can make. Retarding ignition timing can also help in higher hp applications. The general rule of thumb that NX uses is 2 degrees for every 50hp gain over 150hp. So on a V8 you shouldn't have to retart the timing any if you are only running 150hp or less. In many cases a higher flowing fuel pump may be necessary. Higher octane (100+) racing type fuel may be required as well as spark plugs 1 to 2 heat ranges colder than normal with gaps closed to .025"-.030". For gains over 250 HP, other important modifications could be necessary in addition to those mentioned above. These special modifications may include a forged crankshaft, a high quality race type connecting rods, a high output fuel pump dedicated to feeding the additional fuel demands of the nitrous system, and a racing fuel with high specific gravity and an octane rating of 110 or more.

Q: How does nitrous work?
A: Nitrous oxide is made up of 2 parts nitrogen and one part oxygen (36% oxygen by weight). During the combustion process in an engine, at about 572 degrees F, nitrous breaks down and releases oxygen. This extra oxygen creates additional power by allowing more fuel to be burned. Nitrogen acts to buffer, or dampen the increased cylinder pressures helping to control the combustion process. Nitrous also has a tremendous "intercooling" effect by reducing intake charge temperatures by 60 to 75 degrees F.

Q: How long will the bottle last?
A: This largely depends on the type of nitrous kit and jetting used. For a NX system, the calculation is you will use .8lbs for every 100hp per 10sec. So if you are spraying 100hp you should be able to get 6-8 good 10 sec. runs out of a bottle.

Q: How long can I hold the nitrous button down?
A: It is possible to hold the button down until the bottle is empty. However 15 continuous seconds at a time, or less, is recommended. This is due to the solenoid magnets can overheat and melt if run longer than 15 sec.

Q: When is the best time to use nitrous?
A: At wide open throttle only (unless a progressive controller is used). Due to the tremendous amount of increased torque, you will generally find best results, traction permitting, at early activation. Nitrous can be safely applied above 3,000 RPM under full throttle conditions.

Q: Is nitrous oxide flammable?
A: No. Nitrous Oxide by itself is non-flammable. However, the oxygen present in nitrous oxide causes combustion of fuel to take place more rapidly.

Q: Will nitrous oxide cause detonation?
A: Not directly. Detonation is the result of too little fuel present during combustion (lean) or too low of an octane of fuel. Too much ignition advance also causes detonation. In general, most kits engineered for stock type engines will work well with premium type fuels and minimal decreases of ignition timing. In racing application where higher compression ratios are used, resulting in higher cylinder pressures, a higher fuel octane must be used as well as more ignition retard.

Q: Is there any performance increase in using medical grade nitrous oxide?
A: None! Most sell only the automotive grade, called Ny-trous Plus. Ny-trous Plus contains a minimal amount of sulfur dioxide (100 ppm) as a deterrent to substance abuse. The additive does not affect performance.

Q: Is it a good idea to use an aftermarket computer program in conjunction with an nitrous system?
A: Only if the program has been designed specifically for use with nitrous oxide. Most aftermarket programs use more aggressive timing advance curves to create more power for a naturally aspirated motor. This can lead to possible detonation. You may wish to check with the manufacturer of the program before using it.

Q: Does nitrous oxide raise cylinder pressure and temperatures?
A: Yes. Due to the ability to burn more fuel, this is exactly why nitrous makes so much power.

Q: Are there any benefits to chilling the nitrous bottle?
A: No. Chilling the bottle lowers the pressure dramatically and will also lower the flow rate of the nitrous causing a fuel rich condition and reducing power. On cold evenings you might run on the rich side. For optimal running conditions, keep bottle pressure at approximately 1050psi (for a NX system, this varies if you are using another brand)

Q: Are there benefits to using nitrous with turbo or super-charger applications?
A: Absolutely! In turbo applications, turbo lag is completely eliminated with the addition of a nitrous system. In addition, both turbo and superchargers compress the incoming air, thus heating it. With the injection of nitrous, a tremendous intercooling effect reduces intake charge temperatures by 75 degrees or more. Boost is usually increased as well, adding to even more power.

Q: What affect does nitrous have on an engine with considerable miles on it?
A: This depends largely on the actual condition of the engine components. Any performance modification to an engine that is worn out or poorly tuned will have detrimental effects. However, an engine in good condition, with good ring and head gasket sealing, should be able to use nitrous without any abnormal wear.

Q: Will the use of nitrous oxide affect the catalytic converter?
A: No. The increase in oxygen present in the exhaust may actually increase the efficiency of the converter. Since the use of nitrous is normally limited to 10-15 seconds of continuous use, there usually are no appreciable effects. Temperatures are typically well within acceptable standards.

Q: Can high compression engines utilize nitrous oxide?
A: Absolutely. High or low compression ratios can work quite suitably with nitrous oxide provided the proper balance of nitrous and fuel enrichment is maintained. Nitrous kits are used in applications from relatively low compression stock type motors to Pro-Modifieds, which often exceed 15 to 1. Generally, the higher the compression ratio, the more ignition retard, as well as higher octane fuel, is required.

Q: Can service station fuel be used for street/strip nitrous oxide applications?
A: Yes. Use of a premium type unleaded fuel of 92, or greater, octane is recommended for most applications. Many nitrous systems are designed for use with service station pump gas. However, when higher compression or higher horsepower levels are used, a racing fuel of 100 octane, or more, is a good idea to use.

Q: What type of cam is best suited for use with nitrous oxide?
A: Generally, cams that have less exhaust overlap and more exhaust duration. However, it is best to choose a cam tailored to normal use (when nitrous is not activated) since 99% of most vehicle operations is not at full throttle. There are special cam grinds available for nitrous competition which have more aggressive exhaust profile ramping, etc. Since cam selection depends largely on vehicle weight, gearing, etc., it is best to stick to cam manufacturers' recommendations for your particular goal.

Q: Should I modify my fuel system to use nitrous oxide?
A: Most stock fuel pumps will work adequately for smaller nitrous applications. It is important to check to see if your pump can flow enough fuel to your existing fuel system (whether carburetor or fuel injected), as well as being able to supply the additional fuel required by the nitrous kit under full throttle conditions. It may be a good idea to dedicate a separate fuel pump to the nitrous kit.
Q: Which is the best position to mount a nitrous bottle?
A: Nitrous bottles come with siphon tubes and, in order to maintain proper nitrous pickup, it is important to mount the bottle correctly. We recommend mounting the bottle at approximately 20-30 degrees angle with the valve end higher than the bottom of the bottle. The valve end of the bottle should point to the front of the vehicle and the label should face straight up.

Q: How important is it to use nitrous and fuel filters in a kit?
A: Some of the most important components of any nitrous system are nitrous and fuel filters. The filters will keep contaminants from clogging the solenoids and/or jets.

Q: What are the advantages of using nitrous compared to other performance options?
A: The cost of many other performance options can put you in the poorhouse. Dollar for dollar, you can't buy more performance with less money than nitrous. With a nitrous system, performance and reliability can be had for a much more reasonable price while still retaining the advantage of a stock engine during normal driving. And, nitrous offers tremendous gains in torque without having to rev the engine to excessive rpm's.

Q: How do I know how much nitrous is left in the bottle?
A: The most reliable method is to weigh the bottle to determine how many pounds remain. When a bottle is near empty (about 20% or less nitrous remaining) a surging effect is normally felt.

Q: What is the function of the blow-off safety valve on the bottle?
A: It is very important not to overfill a bottle; i.e., a 10 lb. capacity bottle should not be filled with more than 10 lbs. of nitrous oxide by weight. Over-filling and/or too much heat can cause excessive bottle pressures forcing the safety seal to blow and releasing all the contents out of the bottle.

Q: Will I have to change my ignition system?
A: Most late model ignition systems are well suited for nitrous applications. We recommend that you change the spark plugs for a set that are 2 heat ranges colder and gap them at .035".


Yes. Just make sure that you have the correct safety equipment before you do so.

WOT Switch
Window Switch

WOT - Wide Open Throttle Switch. It is placed inline with your arming switch, FPSS, and any other safety devices to activate your nitrous. This can be placed either near the throttle body or a momentary push button underneath the gas pedal for a stealth install.

Window Switch - Another wonderful (shouldn't be without) safety device. A must for a M6. It also installs inline with your FPSS, WOT, arming swithch, etc. The window switch does excatly what it says, it is a window for your nitrous to activate. Example. If you have you window switch setup for 3k and 6k, then the nitrous will only activate between those RPM's. It will come on at 3k and automatically shut off at 6k. (Providing it is wired correctly.) Some use pills while others just use dials or dip switches to set the corresponding RPM.

FPSS- Fuel Pressure Safety Switch. This is a simple little part that is very important to have on any/all nitrou systems IMHO. Basically it just senses fuel pressure going to the fuel solenoid and if the pressure drops to an unsafe level it will shut down the nitrous system before severe damage occurs.

Keep in mind it might need to be adjusted a little but it covers some good stuff. might be valuable to newbies like myself.

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