Drag Racing Information
Nitrous FAQs From the original web site of NOS
Saturday, 20 January 2001 08:00

Nitrous FAQs
From the original web site of NOS

How Does Nitrous Oxide Work?

There are three points. First, nitrous oxide is comprised of 2 parts nitrogen and one part oxygen (36% oxygen by weight). When the nitrous oxide is heated to approximately 572 F (on compression stroke), it breaks down and release extra oxygen, However, it is not this oxygen alone which creates additional power, but the ability of this oxygen to burn more fuel. By burning more fuel, higher cylinder pressures are created and this is where most of the additional power is realized. Secondly, as pressurized nitrous oxide is injected into the intake manifold, it changes from a liquid to a gas (boils). This boiling affect reduces the temperature of the nitrous to -127 F. This "cooling affect" in turn significantly reduces intake charge temperatures by approximately 60-75 Degrees F. This also helps create additional power. A general rule of thumb: For every 10 Degrees F. reduction in intake charge temperature, a 1% increase in power will be realized. Example: A 350 HP engine with an intake temperature drop of 70 Degrees F, would gain approximately 25 HP on the cooling affect alone. The third point, the nitrogen that was also released during the compression stroke performs an important role. Nitrogen acts to "buffer or dampen" the increased cylinder pressures leading to a controlled combustion process.

Why Nitrous?

Nitrous oxide injection has become a very popular option for today's performance enthusiast for several reasons:

  • 1. Nitrous offers you more performance per dollar spent than any other performance modification.
  • 2. Nitrous installations are relatively easy to accomplish.
  • 3. Since Nitrous is used only when needed, it offers you the advantages of complete driveability and normal gas mileage while not "on the button."
  • 4. Systems available for virtually any power need from 25 HP to over 500 extra HP.
  • 5. One of the few performance options available for today's computer controlled, fuel injected engines.
  • 6. Systems can easily be removed or transferred to another vehicle.

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 component 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. All NOS 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, 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 (13B rotaries) 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 kind of testing or research is performed on NOS products?

A: NOS maintains a complete research and development center including computerized dynamometer equipment as well as a nitrous/fuel flow testing facility. In addition, NOS is actively involved in many aspects of racing; working close with many top name racers to develop the most powerful, reliable nitrous systems in the world.

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 quater-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 recommend.

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 2,500 RPM under full throttle conditions.

Q: Does NOS manufacture 50-state legal nitrous systems?

A: Yes, in fact NOS has several EO numbers for various kits such as the 5.0L Mustang and 305/350 GM V8's, etc. In addition, there is no need to remove any smog equipment when installing a NOS system. For more information call the NOS tech line.

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 of our kits engineered for stock type engines will work well with premium type fuels and minimal decreases of ignition timing. In racing applications 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: Where can I get my bottle refilled?

A: Every NOS kit contains a geographical list of refill dealers near you in the U.S. and Canada. Should you need a new list, simply call NOS.

Q: Is there any performance increase in using medical grade nitrous oxide?

A: None! NOS recommends and sells 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 chip in conjunction with an NOS System?

A: Only if the chip had been designed specifically for use with nitrous oxide. Most aftermarket chips use more aggressive timing advance curves to create more power. This can lead to potential detonation. You may wish to check with the manufacturer of the chip before using it. The top manufacturers, such as Hypertech do make special chips for use with nitrous.

Q: How long does it generally take to install an NOS kit?

A: The majority of NOS kits can be installed using common hand tools in approximately 3 to 5 hours. NOS instruction manuals are by far the best in the industry; they include specific installation drawings, wiring diagrams, and bottle mounting procedures as well as performance tips and a thorough trouble shooting guide.

Q: Which type of manifold is better suited for a plate injector type of nitrous system, single or dual plane manifold?

A: As long as he manifold doesn't interfere with the spray pattern of the bars, either will work fine in most cases. The distribution is better with a single plane at high RPM. If your goal is to increase power by more than 200 HP, the single plane manifold is better.

Q: Does nitrous oxide raise cylinder pressures 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 800-900 psi. NOS has a nitrous pressure gauge that allows you to monitor this. If you live or operate a nitrous system in colder climates, it may also be a good idea to purchase a bottle heater kit, part #14161. Generally, ambient temperatures of 70-90 degrees F. will allow for best power potential of NOS kits.

Q: Are there benefits to using nitrous with turbo or supercharger 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: How complete is an NOS kit?

A: NOS prides itself on offering the most complete systems on the market today. They include virtually every component that may be needed for a complete installation; parts such as extra long carburetor studs, gaskets, pipe tap, fuel hose, brackets, filters, fittings, hardeare, wiring, filled 10 lb. bottle with Hi-Flo valve, complete instruction manual, and all other major components are standard in every NOS kit.

Q: What is the difference between a standard and a NOS Hi-Flo bottle valve?

A: The orifice of the Hi-Flo valve is much larger than the standard valve allowing for a larger flow of nitrous. With a small orfice valve a pressure drop could occur when nitrous flow is high; causing surging or inadequate nitrous flow. The NOS Hi-Flo valve eleminates this problem. NOS Hi-Flo valves are standard in all NOS kits.

Q: What effect 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 10-20 seconds of continuous use, there usually are no appreciable effects. Temperatures are typically well within acceptable standards.

Q: Will the percentage of performance increase be the same in a highly modified engine compared to a stock engine when using the same NOS kit and jetting?

A: Not really. In most cases the percentage of increase is greater from a stock engine because it is not as efficient as the modified engine in a normal non-nitrous mode. However, since the effects of nitrous oxide magnify the output of any engine, the total power output will be much higher in the modified engine.

Q: Can high compression engines utilize nitrous oxide?

A: Absolutely. High or low compression ratios can work quite suitably with nitrous oxide provided the propler balance of nitrous and fuel enrichment is maintained. NOS 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. For more specific information talk to one of our technicians.

Q: Can service station fuel be used for street/strip nitrous oxide applications?

A: Yes. Use of a premium type leaded or unleaded fuel of 92, or greater, octance is recommended for most applications. Many NOS 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, must be used.

Q: Are NOS kits applicable on late model EFI cars?

A: Yes, in fact NOS has by far the most comprehensive selection of nitrous kits available for these cars. Call for your specific application if you do not see it listed.

Q: What type of nitrous system is better; a plate injection system or a direct port injection system?

A: The advantages of a plate system are ease of installation and removal, ability to transfer easily to another vehicle, ability to change jetting combinations quickly, and, in most cases, provide you with all the extra HP you will ever need (75 to 350 more HP). In some cases, such as in-line type engines with long runners, a direct port type system is advisable for maximizing distribution. Also, where more than 350 HP is needed, our direct port Fogger systems will provide the ultimate in distribution and power (up to 500+ HP). Direct port injection is also desirable when the system is hidden under the manifold.

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: NOS 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 a 15 degree 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 valve knob and 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. To keep contaminants from attacking the solenoid or plugging up a jet, NOS nitrous filters feature a special stainless steel mesh element from the aerospace industry.

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 retaining the advantages of a stock engine during normal driving. And, nitrous offers tremendous gains in torque without having to rev the engine to excessive rpm's. These factors help your engine last longer than many other methods ofboosting horsepower.

Q: What kind of pressures are components subject to in a typical nitrous kit?

A: Pressures often exceed 1,000 psi. This is why NOS uses only high pressure tested aircraft quality components like stainless steel braided Teflon lines throughout its systems.

Q: How do I know how much nitrous is left in the bottle?

A: The most reliable way 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 lb. 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. In some higher HP cases, it may be advisable to look into a high quality high output ignition system.

Racing Tips for the Manila Harbour Centre Article by: Dr. CLunky
Saturday, 18 November 2000 08:00

Racing Tips for the Manila Harbour Centre
Article by: Dr. CLunky

Drag racing is a very tough sport. Finding every "little" advantage over your opponent is part of the game. Below is a lsit of Racing Tips, specifically for the Manila Harbour Centre strip. These tips were compiled after watching hundreds of passes down the strip by street cars as well as race cars. You may already be doing some of these things, but if you do all of them, I'm confident that you can extract better and more consistent performances at the track.

Use the RIGHT lane.
This lane has been used for ALL record setting runs. There is already a layer of rubber build-up extending till the 60 foot marker, making this lane "stickier" than the left lane.

right_lane2.jpg (17440 bytes)

Know your time for BOTH lanes. Each on the lanes at the MHC run differently. The left is the slower lane, while the right is a bit faster. This is due to the traction differences between them. Practice on both lanes so you know what you will be dialing-in. Make sure to CHANGE your dial-in according to the lane you are using.

Place tires on the "black tire marks". This is the rubber build-up I mentioned earlier. Place your tires right on these marks. The rubber to rubber contact will aid your launch, improving 60' times.(note: you may need to launch at a higher RPM than the left lane)

tire_marks.jpg (18351 bytes)
This car spun its tires, since the tires WERE NOT placed on the black tire marks.

right_lane.jpg (21172 bytes)
Note how this "Pro Class" driver places his tires RIGHT on the marks.


For better reaction times with stock (or near stock) cars, "deep stage". These cars react slower than race cars. Deep staging or staging deeper than normal will move your car closer to the guard beam. That means, you will trip the timer sooner, lowering your reaction times. (note: its easier to redlight when deep staged)

deep_stage.jpg (9731 bytes)

FOR PROSPEED Events: run you "qualifying runs" LATER in the session (cooler air temps). Typically, time trials start at 3pm and end at 6pm. If you make a run at 3pm, chances are, you can run a bit quicker at 5pm to 5:30pm. The air temps have dropped enough that your times will improve. For those who qualify at the bottom of their class (aka, on the "bubble"), this may mean the difference of being in Pro Class D or Pro Class C!

Establish a "routine" and STICK to it!

For example:
1. You do a 5 second burnout
2. then move to the staging lane.
3. You wait for your opponent to Pre-Stage
4. then you Pre-Stage
5. then he stages.
6. Then you stage (deep or shallow).
7. Then you rev up to lauch RPM.

Doing this will allow your mind to focus better at the job at hand. This will ensure more consistent results. There are so many things to watch out for in drag racing, so FOCUS is very important.

Do a BURNOUT! Not the spin the tires for .25 seconds, I mean GET SOME HEAT in to those tires! Especially street tires (yes, even those sticky intermediates) don't heat up very easily. When I mean hot, I mean over 100 degrees F! And if you are worried about tire wear, let me tell you that burnouts don't eat up tires as much as you think! It takes a lot to wear out tires. Even slicks. I used to do HUMUNGOUS burnouts at English Town and I still went a whole season with my Mickey Thompson ET Drags (I raced twice a month, plus I street raced EVERY weekend)! That's well over 100, 5 second burnouts.

burn_out.jpg (9483 bytes)

Set up your car for the first 1/3 of the track. Its the MOST IMPORTANT section. Most people think that if you make a mistake at the start, you can make it up at the top end. Let's analyze this briefly. On a 15 second run, you spend half that time on the first 1/3 section of the track. That's 7.5 seconds! The remaining 7.5 seconds is run in the last 2/3. Remember, too, that what ever time you make up in the beginning, translates ALL the way down to the finish line! So, improve a tenth at the 60' mark, you just improved you ET by a full tenth of a second! It's not only much easier, but also MUCH CHEAPER than building enough HP to improve a tenth at the "big end" of the track.

first_third.jpg (19931 bytes)

Try to get the "right lane". Organizers won't like this too much, but if your opponent is not paying attention, you can take his advantage away! This can make for delays in the running of Eliminations. But, the few of you that read and take this advice WILL benefit if your opponent DOESN'T know about LANE CHOICE! It won't work all the time, but, this can be the difference between winning and losing.

left_lane.jpg (15683 bytes)
Notice how this easily this car spins its tires

Stage LAST. Make SURE that the starter is READY. Many times, the people at the timing system didn't get to see the car numbers (due to crowds blocking their view), and both cars are already staged and revving up their engines, only to be told to back off the line. WAIT to make sure that the starter IS READY. Don't worry about your opponenet. Let him load up his plugs (revving the engine at high rpms for a long time with no load tends to do this). His launch won't be as good (esepscially if his car is HIGHLY modified!). Stage when ONLY when you know everything is set.

stage_last.jpg (16422 bytes)

Do your burout LAST. Let the other guy do his first. Make him wait for you at the line. Before doing your burnout, make sure that you won't be sitting at the line for too long. Your tires will, negating your burnout. This happens all the time. You will have the advantage when you tires are HOTTER than your opponent's.

In the LEFT lane, use your handbrake to hold your car steady while staging. The car tends to roll more there than the right lane. Tape up the button on the hand brake to make sure you don't make a mistake of leaving it engaged! It's recommended to do this in both lanes, but more so in the LEFT lane.

Stage deeper in the LEFT lane. Due to tire spin, caused by having less rubber accumulation, cars REACT slower in the LEFT lane. Staging deeper than normal will compensate for this.

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