Quote from the official NOS site
There's really nothing mystical about nitrous oxide and its application for engines. Very simply, NOS made it better and safer for customer use. The following questions and answers are typical of those fielded by NOS R&D people and we hope that they will be of help to all of those who seek the winning edge.
Q: Will Nitrous affect engine reliability?
A: The key is choosing the correct HP 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. NOS 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. All NOS kits are designed for maximum power with reliability for a given applications.
Q: Can I simply bolt a nitrous kit onto my stock engine?
A: Yes. NOS manufactures 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 40-60 HP, 6 cyl. engines usually work great between 75-100 extra HP, small block V8's (302/350/400cid) can typically accept up to 140 extra HP, and big block V8's (427-454) might accept from 125-200 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: Genreally, forged aluminum pistons are one of the best modifications you can make. Retard igntion timing by 4-8 degrees (1 to 1-1/2 degrees timing retard per 50 HP gain). In many cases a higher flowing fuel pump may be necessary. Higher octane (100+) racing type fuel mya be required as well as spark plugs 1 to 2 heat ranges colder than normal with gaps closed .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 requirements of the nitrous system, and a racing fuel with high specific gravity and an octane rating of 110 or more. For more specific information about your application, please contact the NOS technical dept.
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 much performance improvement can I expect with a nitrous system?
A: For many applications an improvement from 1 to 3 full seconds and 10 to 15 mph in the quarter mile can be expected. Factors such as engine size, tires, jetting, gearing, etc. will effect the final results.
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.
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.
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 2500 RPM under full throttle conditions.
----------------------------------
Notice the how long u can hold it paragraph
