In our quest to pump up the power on our Project 2001 Nissan Sentra SE, we decided that it was time to add a big-time boost by adding nitrous oxide injection. So naturally we contacted Holley to arrange to have an NOS brand system installed. We connected with NOS technical engineer Mike Flynn, who arranged to have a bolt-on street-legal system installed at So-Cal Speed Shop in Pomona, California, a retailer and installer of NOS products.

In less than eight hours, the bolt-on NOS system was installed, safely adding 35 to 40 horsepower when the car is under full acceleration, with no engine modifications needed.

A little history lesson first. The use of nitrous oxide (N20) as a performance enhancement has been traced back to World War II, where it was employed to give Allied aircraft “emergency” boosts in both airspeed and altitude capabilities. However, with the advent of jet propulsion at the end of WWII, the government’s interest in piston-powered aircraft waned. And for the most part, nitrous R&D was shelved. There were sporadic attempts at using nitrous oxide in race cars over the next few decades, but since for the most part it was a clandestine, closely guarded secret, not too many people were aware of its existence.

Finally, in the 1970s, nitrous “came out of the closet” and was the hot topic of conversation. Especially since a number of entrepreneurs brought systems to market that were highly erratic, at best. It was at this point in time when a couple of successful automotive technicians and racers, Mike Thermos and Dale Vaznaian, saw that there was a potential for nitrous… if done right.

In 1978, Mike and Dale formed Nitrous Oxide Systems, Inc. (NOS), and the rest is history. They didn’t invent nitrous oxide, they simply perfected its use and elevated it to a position of prominence. NOS has always been known for thoroughly engineering each application, using only the best quality materials, and producing kits that were easy to install and built for long service.

Perhaps the greatest boost to the popularity of nitrous oxide was the advent of drag racing’s Pro Mod class. Early pioneers captured the imagination of race fans with their impressive performances with stock-bodied cars. And NOS was there for every performance milestone: the first 200-mph run by a “door slammer,” the first 6-second run, etc. In fact, every single key performance milestone with nitrous has been set by racers using NOS systems. And the same holds true today with import racing.

Of course, action movies have always used nitrous on their cars in driving and chase scenes to smoke the rear tires. Last year’s hit, The Fast And The Furious, prominently featured NOS systems, “boosting” N20’s popularity even more in the Euro market. Today, as a Holley brand, and with more than 20 years experience building nitrous systems for racing and street applications, NOS remains as the dominant force in the industry. A great deal of the company’s success can be attributed to its ongoing pursuit of perfection and extensive R&D efforts. Another key factor is the relationships that NOS has forged with leading racers and professional engine builders. Their input has served to keep the company on the leading edge of technology.

Now, a little physics lesson. How does nitrous oxide boosts an engine’s horsepower? Nitrous oxide is made up of two nitrogen atoms and one oxygen atom held together by a chemical bond (33-percent oxygen, 66-percent nitrogen). An engine works by burning fuel, so you can make more horsepower by burning more fuel, but you must also add more oxygen. Nitrous allows you to add more fuel, but all of the power comes from the fuel, not the nitrous. Gasoline doesn’t burn in a liquid state. It must be turned into a vapor. The smaller a fuel droplet is, the more efficiently it can be evaporated.

Because nitrous systems add atomized nitrous and fuel, they offer an efficient horsepower increase. The other way that nitrous boosts horsepower is by cooling the air/fuel mixture. When nitrous oxide is injected, it instantly goes from liquid to gas, becoming very cold. This drops the temperature in the intake by as much as 65 degrees F.

Now that you know a little bit more about nitrous, follow the photos as we show you how easy it is to add a 35 to 40 horsepower boost safely, with an NOS kit from Holley. Note: This is an “entry level” system designed for everyday street use. Greater horsepower gains are possible with other NOS kits, but additional engine modifications and “colder” plugs are needed as well.