For as long as I can remember being into cars and trucks, I've wanted to own something with nitrous on it. Without a doubt, nitrous oxide is the absolute cheapest horsepower available. But I'd never had any experience with it. In fact, up until I went to Westech Performance and put two NOS kits on a carbureted Chevy and a fuel-injected Dodge, I'd never even been in a vehicle with nitrous oxide, much less had any personal experience. There are so many taboos with nitrous, and that's why the majority of the public stays away from it. But as I have learned with recent experience, those fears are exaggerated. Yes, it is possible to destroy an engine if something goes wrong, but with the almost foolproof nitrous oxide-safety systems available today, those fears aren't really justified anymore. NOS systems have come a long way. And yes, NOS is an official company name, but it gets used as slang for any nitrous-oxide system (think Kleenex and tissues).
Nitrous oxide (N2O) is two parts nitrogen and one part oxygen. In a contained form, it is a very cold liquid that turns into a gas when released into the engine's intake stream. Nitrous is about 36 percent oxygen (compared to the air we breathe, which has about 22 percent oxygen), so when the nitrous is injected into your engine you are basically shoving concentrated oxygen into your engine. On top of that, the extreme cold temperature of nitrous allows for a denser charge, improving combustion and increasing power. Nitrous is not a fuel (read: nitrous oxide is not flammable!), but the concentrated oxygen allows more fuel to be burned which increases combustion and cylinder pressure, therefore pushing your engine to do more work (horsepower and torque).
One of the biggest fears people have is the added strain on an engine equipped with nitrous oxide. And what about that additional engine strain from the additional horsepower? Well, let me answer with a question: What do you think a supercharger or turbocharger does to an engine? It doesn't matter if you are getting 150 hp from a forced-induction situation or a squirt of some "juice" - adding extra oxygen so you can add more fuel increases power and subsequently puts more strain on your engine. The beautiful thing about nitrous is that it's only putting the additional strain on your engine when activated. Turbos and superchargers are on 100 percent of the time. Which do you think is worse for your engine?
As far as how much horsepower is safe for your particular engine, well, that depends on how your engine is built and what kind of engine it is. But a very good rule of thumb is that your engine can handle a 33-percent increase in horsepower over what it puts out stock.
Most nitrous systems on the market today are for "off-road use only," though there are a couple application-specific street legal kits on the market. This does not mean you cannot have a nitrous system plumbed into your street-driven vehicle. It does, however, mean that you cannot have the nitrous-oxide bottle hooked up to your nitrous injection system at any time on streets or highways.
The cost of a nitrous system can range from $250 to many thousands of dollars when brains and mastermind electronic controllers are added to the cost. I'd highly suggest staying away from the cheapest system possible, and instead look at a moderately priced, moderate-horsepower system with decent safety controls that will shut the nitrous-oxide flow off if a problem is detected.
You should not be surprised to spend upwards of $600 for a good system, so be prepared to drop more money than an air intake would cost. But how else could you possibly gain 100hp for less than a thousand bucks?
Fuel Injected Nitrous System
(2000 Dodge Durango Magnum 360ci)
My daily driver is an R/T Dodge Durango. It's a nice ride, pretty quick too, but nothing is ever really fast enough for me. I didn't want to lose any of the reliability of my powertrain, nor did I want a bunch of overly-expensive fancy parts that I couldn't replace at any dealership. My best bet was a nitrous oxide system. And when I started doing research, I found that NOS had a Dakota/Durango-specific kit! This was just a very lucky happenstance for me, but that does not mean you are out of luck if there is not an application-specific kit for you. NOS makes various universal EFI nitrous kits that work largely the same as my application-specific kit does. The difference is that you'll have to choose things like your own injector sizes and dictate what is right for your vehicle.
The NOS Dakota/Durango kit is a dry kit, which means it relies on the engine's fuel injectors to supply extra fuel during nitrous engagement. A wet system would include a fuel solenoid along with the nitrous solenoid, and both extra fuel and nitrous oxide would be injected into the engine at the same time. Obviously, much larger horsepower levels can be achieved using a wet system, but for the low horsepower squirt I was looking for, a dry system was more than adequate.
Was I pleased? Oh, yes. The kick when the nitrous engaged was very mild, because we only put a 60hp shot on the vehicle. On the dyno, we made a best of 219.7hp and 346.1 lb-ft of torque at the rear wheels without nitrous. On the juice, the Durango made 260.5hp and 411.2 lb-ft of torque. It was not quite the 60hp gain on the side of the box, but I gained 60 lb-ft of torque, which was more important to me.
Nitrous is For Anything!
Off Nitrous: 219.7 hp, 346.1 lb-ft of torque
On Nitrous: 260.5 hp, 411.2 lb-ft of torque
Carbureted Nitrous Kit
(1972 Chevy K20 Vortec 454ci)
We also wanted to see a carbureted nitrous system. Typically, carbureted nitrous systems are less complex and generally cheaper. My buddy, Darren Rizucka has a 1972 Chevy K20 4x4 with a basically stock Vortec 454ci engine in it. He's got it carbureted, and it's his daily driver. He is always looking for a bit more horsepower as well, so what better candidate to try a carbureted wet system?
I ordered a NOS 175hp Super Powershot kit for his truck, which was probably overkill for the way his engine is currently built. If his truck was running correctly, it should put out over 350hp. We weren't going to use a 175hp jet and instead were going with a 125hp jet (which was closer to 1/3 of his total power). Make sure not to over-jet your nitrous system and burn up your engine. If we had put the 175hp jet in, we would be adding roughly 50 percent of his total engine power when the nitrous was activated. This is too much for a normally built engine to handle.
Darren Rizucka's '72 Chevy was much more entertaining to watch get the juice. When the 125hp nitrous shot kicked in, the engine screamed, the whole truck lurched forward, and the dyno straps strained. It just sounded sick as the truck ramped up to almost 500 lb-ft of torque. Off nitrous, the carbureted Vortec 454 made 264.4 hp and 362.8 lb-ft of torque. On the juice, this blue '72 made 359.2 hp and 498.0 lb-ft of torque. There were still some ignition problems, even after dialing in the timing, so this truck will probably have to receive a new distributor to optimize timing and make full power both on and off the nitrous.
Nitrous is for Anything!
Off Nitrous: 264.4 hp, 362.8 lb-ft of torque
On Nitrous: 359.2 hp, 498.0 lb-ft of torque
Q&A With Westech Performance>
Do you have to change fuel injectors using nitrous?
Yes and no. With a wet system, you do not have to. It is possible to need to change fuel injectors with a big shot dry system, but most dry systems are rather mild in horsepower gains anyways, negating a need for larger injectors.
What is wet?
A wet system is when both nitrous and extra fuel are added to the system through the use of a nitrous solenoid and a fuel solenoid that usually piggybacks off the fuel line. The additional fuel added when the nitrous is activated keeps the air/fuel ratio balanced.
What is dry?
A dry nitrous system relies upon enriching the fuel mixture through either the ECU or by fuel pressure. A dry system is typically a minimal horsepower gain system like a 25hp shot or a 60hp shot.
How big of a shot is safe?
33 percent of the engine's max horsepower
What are different types of injection methods?
Plate (in between the carb and manifold), fogger (single nozzle into the air intake), and direct-port injection
How many shots can you get out of a bottle?
It depends on the bottle size (usually 5-, 10-, 15-, or 20-pound sizes), and how big the horsepower shot is.
What are typical increment jumps for nitrous nozzles?
There are as small as 25hp jets up to 500hp jets. Most higher horsepower shots are dual- or even triple-staged with lower horsepower shot coming on before the top shot. There are typical jet sizes of 25hp, 60hp, 75hp, 100hp, 125hp, 150hp, 175hp, 200hp, and 500hp available.
Is nitrous safe?
If installed correctly with the appropriate equipment, nitrous is safe. It is no more abusive on your engine than a supercharger, plus it offers a cooling effect in the engine
Will the tank ever blow up?
No, it has a safety blow-off valve. Also nitrous is not flammable.
Do I need an optional purge kit?
No, but for consistency it's a good idea.
Can I have the bottle in the cab?
You can, but you should also have a blowdown tube that vents the bottle if it becomes overheated.
Will I feel any nitrous effects to my body if the bottle is in the cab?
You've been watching Tommy Boy too much. Don't try it. Nitrous for your car is not the medical-grade stuff the dentist gives you.
Is it street legal?
There are some 50-state legal kits, but they are rare and application-specific (not your application). It is legal to have your vehicle plumbed for nitrous, but the bottle must be unhooked, however.
Where can I get a bottle filled?
You'll need to find a speed shop in your area that carries nitrous oxide
When can I use nitrous?
You can use it off-road or at a track. It should only be activated at wide-open throttle and above 3,000 rpm.
Do I have to use special fuel?
No, though you should use premium fuel.
Do I need to change my ignition?
Yes, in fact it is a good idea to close the spark-plug gap about 0.010, and using plugs 1-2 steps colder isn't a bad idea either.
Ignition should be retarded about 2 degrees per 50hp, but it's best if the ignition is only retarded when the nitrous is engaged. An aftermarket electronic ignition can make this possible even on old carbureted vehicles.
Will it lower the life expectancy of my engine?
Any large increase in horsepower will typically wear out your engine faster. If you are emptying bottles three times per week, than your engine could wear out prematurely.
Do I have to do any other engine work to adapt nitrous to my vehicle?
Generally, no. It is very beneficial to tie your nitrous system into an electronic ignition system and you may need to piggyback off of a fuel line, but it is not mandatory to make any modifications to install nitrous. For larger horsepower shots, better pistons should be installed and you may want to add head studs to the engine block.
Can I use nitrous all the time?
Don't be dumb.
I've heard it is the cheapest HP available. Is that true?
Far and away, yes. You can buy a good 150hp nitrous system for less than $800.
Is there any kind of warranty implied with using NOS?
Uh, you break it, you buy it? Nitrous is installed at the vehicle owner's risk. If a part of the nitrous system malfunctions, then NOS will certainly stand behind its product. But you're not getting any money if you blow up your engine getting overzealous.
Is it something I can install myself?
Many nitrous kits are fairly easy to install, but we suggest having an experienced installer at least with you when installing if you've never plumbed a nitrous kit before.
Will it get me chicks?
What is a multiple-stage nitrous system?
A multi-stage nitrous-oxide system is set up to blend two or more horsepower shots of nitrous into the mixture, progressively stepping up. It would be very violent to inject a straight 500hp shot, so systems often step up from nothing to a 250hp shot to 500hp as not to make the engine's reaction so violent (possibly breaking internal parts)