Camaro and Firebird 3.8L Nitrous Guide


Q: What supporting mods do I need?

A: For any amount of nitrous you will need aftermarket intake and cat-back exhuast because the car must be able to breathe. Ever try sprinting 100 yards while only breathing thru a straw? Its hard on your body just like nitrous is on a car that cant breathe.

The next mod you will need is spark plugs, NGK TR6 are the prefered plug of almost all nitrous users. These plugs are a step colder and are gapped at .035 to prevent detonation. DO NOT RUN STOCK PLUGS!

Q: How big of a shot can I run on my 3.8 Fbody?

A: Most people run a 75-100 shot and havent had any problems. Our cars will run safely up to an 85 shot with no other supporting mods than what are listed above.

With a dry kit, any more than an 85 shot it is reccommended to upgrade the fuel pump with a Walbro 255lph intank pump or an MSD inline pump. That will be good up to a 100 dry shot, any more than a 100 dry shot and its reccomended to upgrade the fuel injectors to 36 lbs/hour injectors.

With a wet kit you can run up to a 100 shot without fuel mods because you can simply put in a bigger fuel jet to add more fuel. After that, a higher flowing fuel pump is highly recommended.

All in all, 125 seems to be the “safe” limit on the stock internals. Any more than that and forged pistons and rods are a good idea.

Q: What kind of fuel should I run?

A: Minimum of 92 octane or else you will get knock retard…not good. If there is 93 available, get it. Nitrous motors need high octane to control timing. Do not run 87 octane.

Q: Is nitrous safe?

A: Nitrous is safer than most people give it credit for. It gets a bad name from people who have no idea what they are doing, slap on a nitrous kit with no supporting mods, run too big of a shot and blow the motor then blame the nitrous. Nitrous is just as safe or dangerous as a turbo or supercharger, its just having the right supporting mods to accomodate the extra power increase.

You can safeguard your car by using an FPSS, running the right size shot for your mods, window switch, fuel upgrades (if needed), running the right fuel, a good tune (more on this later), spraying only at WOT and only spraying when your nitrous pressure is at 900-1150 psi.

Q: Do I need a tune for nitrous?

A: Tuning is not a necessity, however, it can greatly help your motor maximize the nitrous shot. Its a rule-of-thumb that for every 50hp of nitrous, that the timing be retarded 2*. Thats pretty general though. I highly recommend a tune also because the air:fuel ratio can be correctly adjusted. Too much air and the motor will run lean possibly resulting in a burned up piston…not good. Too much fuel and the motor will run rich which fouls spark plugs and robs horsepower.

Q: Why are window switches so important for manual tranny cars?

A: Because they prevent the motor from hitting the rev limiter while spraying. If the motor hits the rev limiter while spraying, plan on buying a new motor.

Q: Where can I tap for fuel for my wet kit?

A: Two ways: Cut a fuel line coming from the fuel tank and put in Tee fitting.

Or simply take out the shrader valve from the dead end of the fuel rail and put the -4AN line right on it. This valve is located on the passenger side of the fuel rail directly behind the alternator (see pic below).

Q: I have over 100,000 miles on my car, can I still use nitrous?

A: That depends on the condition of the car. If the car has been babied and very well maintained (fresh oil changes every 3000 miles, always ran fresh spark plugs, changed all filters regularly etc.) then it should be fine, but remember if there is any kind of flaw anywhere in the motor, nitrous will exploit it and make it worse. The tranny and the rearend must also have been taken good care of because nitrous can do collateral damage to them as well. You are taking bigger chances of doing damage with a higher mileage car. I would suggest doing a leak down test and a compression test before spraying a car with high milage.

Q: If I have an automatic can I spray thru the shifts?

A: Yes, as long as the tranny is in good shape you should be okay. If you have a wet kit with an auto, I personally recommend getting a window switch becuase you still run the risk of spraying below 3000 rpm, puddling the fuel and backfiring out the intake manifold. I have done this and it was not fun or cheap to fix it.

Q: How much do I need to spend to run nitrous safely?

A:That all depends on whether you get new parts or used parts and what brand of parts you get. See links below for prices.

If you wanted to safely run nitrous on your car plan on spending $800-$1500 for parts and $300-$500 for a tune. It all depends on what accessories you choose and the shop who tunes it.

Q: Are there any kits specific to our cars?

A: Well, yes and no. NOS has the 5175 dry kit that is supposed to be specific for our cars, but it can be used on any car if so desired. The only kits that are specific to a certain car are plate kits and direct port kits. Other than that you can use any kit for our cars. If you are unsure if the kit you have or looking to buy will work, post pics of all the parts and we can let you know if it will or will not.

Q: What is a progressive controller?

A: It is a device that regulates the amount of nitrous/fuel injected into the motor over a certain period of time or a certain rpm range. The main purposes are for traction control and to run larger amounts of nitrous without doing as much damage since the power comes on slower and not one huge shot. Some people will use a progressive controller instead of a 2 stage set up. It is wired to the ground wires of the solenoids and pulsates them to control the shot. They range in cost from $125-$800.

Q: Where can I put my bottle?

Totally up to you. There are kits specifically for placing it between the backseats and there are also kits to put it in the spare tire area. I have my bottle in the t-top storage area in the trunk. The back hatch is a popular place as well. Some people even remove one of the rear seats and put it back there. Just make sure where ever you put it, it can be correctly oriented for the best flow of nitrous.

Q: Is nitrous legal?

That all depends on the state in which you live. Check your local state/county/city laws to make sure it is legal or not. In many states even if its illegal, its only a secondary offense.

Install tips:

Look at the stickies above and see that there are links to install instructions for many of the popular kits. If your kit does not come with instructions, contact the manufacturer and ask for them. I have yet to run across a nitrous manufacturer who didnt have install instructions for their kits.

The best thing to do BEFORE installing your system and all the accessories is to look at your car and choose where you want to: a) mount the bottle, b) where you want to mount the solenoids and c) where you want to mount the switches. Knowing all of that will greatly help you set everything up.

Once you figure all that out, install the basic system with no accessories and once its in place and working, then install the accessories. If you have a problem and something doesn’t work then its easier to diagnose the problem by installing everything one item at a time. If everything is installed all at once and something isn’t working right, then it’s a real pain to figure out what is wrong and where its wrong.

When you order all these things and you take them out of the box, you will have a huge mess of wires, but don’t worry. Take your time, install one thing at a time and its not bad at all. The only electronics install experience I had before working my car was installing a CD player lol. But I learned along the way and it wasn’t as bad I thought it was going to be. Moral of the story, I had no idea working with electronics and I survived my install lol. The directions for all of this stuff are pretty clear and simple to read. If you have questions on stuff just ask.

Here is a link to Coldfusion’s website. They have tons of install videos that are EXTREMELY helpful. They are not specific to our cars but they can give you a good idea of what to do: (link at the bottom of the page)

Useful links…ts/default.asp

A few helpful pics:

Good place to tap for fuel for a wet kit:

Good place to install a fogger nozzle for a wet kit:


Nitrous oxide injection is probably one of the most misunderstood modifications in our hobby.
Nitrous oxide is an oxygen bearing compound. Its chemical designator is N2O, so we know each nitrous oxygen molecule has two nitrogen atoms and one oxygen atom. Nitrous oxide is sometimes incorrectly known as “NOS”. That is an acronym for the company, Nitrous Oxide Systems, which is the largest marketer of nitrous oxide injections system for automotive use.

Injection of nitrous oxide into the combustion chambers of an internal combustion engine as a way to increase power output was discovered by the German air craft industry early in the Second World War. Thousands of German figher and reconassance aircraft were equipped with the so-called “GM-1″ system which added nitrous oxide to the intake charge to compensate for reduced air density and less oxygen high altitude. The British Royal Air Force also used aircraft engines with performance enhanced by nitrous oxide. Interestingly, there was no use of nitrous oxide injection by the American military air forces other than very limited experimental use. It is interesting to ask oneself that, if nitrous oxide injection was so dangerous to an engine’s reliability, why would so many airplanes have used it?

In this country during 1950s the famed stock car racer Smokey Yunick rediscoverd nitrous oxide injection as one of his many schemes for winning races until discovered and outlawed by NASCAR. Neverthesless, there have been several nitrous oxide cheating scandals in NASCAR over the years and it is probably still used today by the slowest of backmarkers. In the late-70s/early-80s nitrous oxide was “rediscovered” by drag racers and hot rodders.

Today nitrous oxide injection, like many other modifications such as more aggressive camshafts, bigger carburetors, higher compression ratios, more free flowing intake and exhaust systems, can be a pracitical way to more horsepower. any other modification…perhaps even more so because it so easily lends itself to misuse…there can be a reliabity and durability price to pay.

Nitrous oxide is a colorless, non-flammable gas. It has a slightly sweet taste and odor. It is non-toxic and non-irritating and when inhaled in small quantitites can produce mild hysteria and giggling or laughter. This is were the nickname “laughing gas” comes form. When inhaled in pure form it will cause death by asphyxiation because at atmospheric temperatures and pressure, the oxygen in nitrous oxide is not available to the body.

A property of nitrous oxide is that at about 565 degrees F., it breaks down into nitrogen and oxygen. When it is introduced into the intake tract of an internal combustion engine, it is sucked into the combustion chamber and, on the compression stroke, when the charge air temperature reachs 565 deg., a very oxygen-rich mixture results. If we add extra fuel during nitrous oxide injection, the effect is like a super charger or increasing the compression ratio of the engine. Automotive nitrous systems work like the automotive eqivalent of a jet’s “afterburner” and is used for short duration extra bursts of power.

Nitrous oxide has this effect because it has a higher percentage of oxygen content than does the air in the atmosphere. Nitrous has 36% oxygen by weight and the atmosphere has 23%. Additionally, nitrous oxide is 50% more dense than air at the same pressure. Thus, a cubic foot of nitrous oxide contains 2.3 times as much oxygen as a cubic foot of air. Just do a bit of math in your head and you can see if we substitute some nitrous oxide for some of the air going into an engine than add the appropriate amount of additional fuel, the engine is going to put out more power.

Simply stated, nitrous oxide injection is very much like a supercharger or a compression ratio increase in that, during combustion, it can dramatically increase the dynamic cylinder pressure in the engine.

Of course, when we significantly increase the cylinder pressure in the engine, we also increase the engine’s tendancy to detonate. This is why almost all nitrous motors require retarded spark timing during nitrous oxide operation. The cylinder pressure increase is also why, when misused or improperly installed, operation with nitrous causes problems with head gasket seal and failures of the rings or pistons. I should point out that any number of things that put an engine into severe detonation, such as too much boost from a supercharger, low octane fuel, excessive compression ratio or overly lean air-fuel ratio will also cause the same kinds of damage.

Another challenge with a nitrous oxide system is getting the delivery of nitrous oxide and additinonal fuel at the correct proportions. If you feed nitrous to the engine without enough extra fuel, the lean air/nitrous to fuel mixture will make the detonation problem even worse. Combustion temperatures will skyrocket and catistropic failure is certain to occur. If the proportion is such that too much fuel is delivered, the power advantage degrades rapidly.

As you can see, nitrous oxide is like any other power increasing modification in that, when used wisely and installed properly, it works well. Then used foolishy or installed incorectly it can significantly reduced the reliability/durability of your engine.

Small doses of nitrous oxide can be used in stock engines to gain 25-35% more power. In my opinion, any more than nitrous than that with a stock engine compromises durability too much. This is not only true of nitrous but any modification. Take a stock 82 or 84 engine, up the horsepower to 300hp and do nothing to improve durability and your engine will eventually suffer. Once you pass the 35% power increase mark with nitrous oxide you need to look at things like forged pistons, better connectiing rods, better bearings, etc.

So, nitrous oxide is not the instant-engine-failure many people think it is. When used properly and when dispensed by a properly designed and installed system nitrous oxide can be responsible for some phenominal increases in power.

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