Pete Epple Technical Editor
September 10, 2010
Photos By: Team MM&FF, Courtesy Of Zex, John Zeilinga

Nitrous oxide systems are also nearly maintenance-free. Most are tested to extreme levels to ensure great long-term reliability. "Often there are issues on the electrical side of the system that cause problems," Patrick adds. "If the system is not installed properly and wires are spliced incorrectly, problems can arise.

"The weather and vehicle storage conditions can also affect the electrical side of the system. Over time, the connections can corrode and cause activation failures."

We also recommend periodic inspection of the lines, bottle condition and mount, and the solenoids and underhood hardware.

Tuned Up
Because nitrous has the ability to seriously alter the air/fuel ratio, tuning is extremely important. It's very easy to cross the boundaries of what is safe (lean or rich), and engine failure can occur if your engine and nitrous oxide system are not properly tuned.

"There are many factors that go into tuning a nitrous setup," explains Steve Johnson, owner of Induction Solution, which has years of nitrous tuning experience. "Nitrous systems and engine parameters really need to be tuned on an individual basis for optimal results. Some of the bigger companies will throw out blanket tuning rules, but with today's fuels, cylinder heads, camshafts, and intake manifolds, you really need to tune each setup specifically.

"The best thing you can do is thoroughly read the instructions that come with the kit. Following the manufacturers guidelines will give you a solid starting point for making power." Then take baby steps, first going with a small shot or horsepower increase. And check the spark plugs often, whether dyno or track testing.

Before you install your nitrous system, make sure your engine is in good working order, and know if existing engine components may need to be changed or adjusted. Depending on the system and the amount of nitrous and fuel you are injecting, ignition timing advance may need to be reduced and the spark plugs swapped for ones with a colder heat range. Spark plug gapping may also need to be closed up to prevent a misfire due to increased cylinder pressure.

"There are definitely things that need to be monitored," Johnson adds. "The octane of the fuel, heat range of the spark plugs, timing, and bottle pressure all need to be watched to ensure the combination is running properly."

A properly filled nitrous bottle with proper pressure is what supplies the constant flow of nitrous oxide to the engine. Bottle temperature and pressure are directly related and need to be monitored for consistent results.

Additionally, since bottle pressure is critical, temperature becomes very important. Stored in the bottle, nitrous oxide is a compressed gas-so when the bottle temperature rises, so does the pressure.

According to NOS, its kits are designed to work best between 900 and 1,000 psi of bottle pressure with optimal pressure at 950 psi. This is achieved with a bottle temperature of 85 degrees. If the pressure is too high, the initial hit will be much harder, but the bottle pressure will reduce dramatically and the vapor pressure inside the bottle will not regenerate itself fast enough to supply a constant flow of nitrous for the rest of the run. On the other hand, low bottle pressure will result in a softer initial hit with less pressure fall off over the course of a run.

Companies offer different versions of bottle heaters that give users the ability to control bottle temperature and pressure.

When a 10-pound nitrous bottle is properly filled, it should weigh 24 pounds, 12 ounces. It is very important that nitrous bottles are not overfilled. The bottle is designed to hold a specific amount of liquid-nitrous oxide with room for expansion as the liquid converts to its gaseous state. Over-filling the bottle can result in pressure levels above what the bottle can contain. Though the bottle's valve is designed with a pressure relief valve, too much pressure can cause the bottle to burst, resulting in serious injury or death.

Proper bottle mounting is also important. The pick-up tube in a nitrous bottle generally runs straight through the center of the bottle until the last 5 or 6 inches. At this point, it will turn approximately 45 degrees towards the bottom back section of the bottle. This ensures the pick-up tube remains submerged in the liquid nitrous oxide. If the bottle is mounted incorrectly, the pick-up tube may not be submerged in the liquid nitrous, and nitrous vapor will be pushed through the system. This will cause inconsistent power levels throughout passes at the track.