Nitrous Oxide--"Wet" and "Dry" Kits

Another important factor according to Schnitz is that on most sportbikes there isn't a lot of room for parts. This makes the dry kit even more practical because it has four fewer fuel lines, no extra fuel pump and no fuel solenoid. In Schnitz's experience, "we sell about 70 percent of our nitrous kits at 40 horsepower, then 20 percent of our customers want 50-70 horsepower, and a small percentage want over 75 horsepower." According to Schnitz, "we can get up to 270 horsepower out of a second-gen Hayabusa on the stock fuel system before the fuel pump runs out of capacity, but at some point you have to start thinking about engine upgrades as well. Pistons, valves, valve springs and clutch springs are the most common upgrades to get a sportbike ready for that kind of power."

We also talked to Lee Shierts of Lee's Performance (www.leesperformance.com) in Charlotte, NC. Lee has been building and racing sportbikes for over 25 years and is a member of the ECTA 200 MPH club (he has been officially recorded over 260mph on a standard-bodywork sportbike) and his shop has installed hundreds of nitrous kits over the years. Shierts has personally ridden nitrous bikes in drag racing and land speed racing for many years. "When a customer comes in looking for nitrous, I talk to him about his goals and then help them decide what is best," said Shierts. "In most cases where they want about 70 horsepower, I steer them toward a dry nitrous kit. I can install a complete dry kit in about four hours where a wet kit can take as much as eight hours, not to mention the cost of the parts is about half as much for dry nitrous."

Shierts went on to say that "on a new sportbike with dual fuel injectors it makes tuning and setting up a dry nitrous kit a straightforward deal; we can use the Bazzaz fuel controller to map both sets of injectors, or use two Dynojet Power Commanders. We even have the ability to map the stock ECU and trigger the map when the nitrous is sprayed. Then for safety we can add an rpm window switch to make sure the nitrous only sprays at the right rpm as well as a wide open throttle switch making it almost impossible to spray the juice at the wrong time. Dry nitrous is also easier on engine parts because it comes on softer and doesn't hit as hard as a direct-port-injected wet system. We have made up to 350 horsepower on a Hayabusa and 320 horsepower on a GSX-R1000 using only dry nitrous."

Of course with any nitrous system, proper fuel and retarding the ignition timing is critical, according to both Shierts and Schnitz. Both tuners have their prescriptions for the proper octane fuel and timing retard, but both agree that with a stock motor (1000cc and up) and a 40-horsepower shot of dry nitrous, you can usually get away with 93 octane gas and no timing retard if the bike is mapped properly (again proving the point that dry nitrous is the most bang for your buck when it comes to adding 40 horsepower to your sportbike). "Don't get it twisted though," cautions Shierts. "A bike that makes 220 horsepower on motor will always outrun the 220-horsepower nitrous bike on the street or strip because the power is always there, not just when you spray it." A point to consider, although another is that a 40-horsepower engine build will cost $4500, versus $1200 for the nitrous.

Thanks to the development of EFI and more recently with the added tuning flexibility of dual injectors as well as the aftermarket support from products like the Power Commander and the Bazzaz fuel controllers, adding nitrous to your bike is easier than ever. So even if you are not interested in becoming a nitrous junkie, squeezing an extra 30-40 horsepower out of your bike is something that can leave you laughing and the guy lined up next to you at the dragstrip crying.