Tech Tips

Everything You Ever Wanted to Know About Nitrous Oxide But Were Afraid to Ask

Written by  April 30, 2004

After doing my last article on jetting, I thought I would take things a step further by talking about Nitrous Oxide Systems (NOS). This article is to define what this application can do to a normally aspirated engine, and to introduce you to Larry James of Larry James Racing. Larry is an expert on this subject and one of the silent legends in the Kansas City Metro area.

This story goes back 14 years ago when I moved to Kansas City, Missouri. I had a job offered to me in the motorcycle industry from an independent shop, which has since closed. I had heard from my manager that if you want high performance applications done to your bike, the man, the legend was Larry James of James Racing. It was not long after that, I looked him up. Every person I met who has had work done by Larry has said nothing but great things about his work on cylinder boring, cylinder head work, and transmission undercutting. He just flat out gets the job done right!

It has been some time now, but I have tracked him down again, because I needed my Ninja Transmission undercut. I found out that Larry is the lead tech at Donnell's Motorcycles Inc. in Independence, Missouri. Donnell's Service Manager, Stewart Basey, was kind enough to let me have some time with Larry to talk aboaut what makes Nitrous Oxide applications so popular in today’s racing.

To give you a little background on Larry, he started his career in 1972 at Northeast Honda in Kansas City, Missouri and has been racing for more than 30 years. He built a 1400cc Kawasaki funnybike starting with a 1978 Kawasaki KZ 900 engine with a list of aftermarket parts, too many to count. He purchased a complete NOS kit from Schnitz Racing, which includes the Schnitz computer controller, bottle, two cheater solenoids, fuel pump, all of the electrical switches and lines, and last but not least, the fogger nozzles. Adding these components to Larry’s bike greatly contributed to his whopping 7.19 quarter mile at 184 mph. at the St. Louis International Raceway.

After Larry agreed to open Pandora’s Box for us, he invited me to a lesson in the basics. As it turns out, there's really nothing mystical about NOS and its application for engines. What is NOS? It’s two parts nitrogen and one part oxygen. What does this mean? It means that when you combine these two elements with some extra fuel, what you get is serious engine horsepower gains!

Why does Larry choose NOS? This is the most economical way to increase horsepower other than Turbo Charging. NOS creates more oxygen to burn the air fuel mixture more efficiently than normal driving. When you add more air you need more fuel. This is all governed by the size of the fogger nozzle jets; somewhat like jetting a carburetor. NOS can be adjusted by the size of the jet you install. This is an important process due to the fact that you do not want a lean condition, which will destroy an engine quickly, resulting in extreme expense and unsafe conditions. Larry recommends staying on the rich side to be safe, also make sure your engine is in top running condition and you must have a high flowing fuel system.

This system is a bolt on application that has grown in extreme popularity over the years. NOS applications can be installed on almost all motorcycles manufactured today. There are several size bottles to be considered, which is the main factor. Street racers such as Larry preferred to hide the actual NOS system bottle within the motorcycle frame. After the first race and the times were collected, everyone knew he was on the job and other racers declined the challenge. Larry supports his peer group racers and they come to him for numerous engine questions and machine work and cylinder head modifications.

NOS is universal and can be added to two cycle, four cycle and diesel engines. When you consider adding this application you must take into consideration that this application will greatly take money away from your bank account and consume a lot of time. Most racers you see on TV today have sponsors and a team of tech support behind the scenes. The only thing you see is the end result. The average cost to build a funny bike today with all the bells and whistles runs approximately $60,000. Larry has been in the motorcycle industry for more than half of his life and without his talent and skill he would not be able to race. If you are seriously interested in doing a NOS upgrade to your bike, I suggested you look at all factors involved. These kits start around $400 and can be very expensive if not done correctly.

If you have the balls, the desire, and the available cash to burn, you should have this procedure done by only a qualified seasoned NOS installer. For more information on NOS and some great Q&As check out Holly’s web site.

By Dave Miller