Michael Galimi
September 6, 2007

Speed Demons rejoice-nitrous works great on the S197 Mustangs, and it continues to be the best bang for the buck in the aftermarket. Hot rodders have been gassing their rides since the '70s, and nitrous is as popular as ever.

Nitrous oxide is made up of two nitrogen molecules combined with one oxygen molecule. Under extreme heat in the combustion chamber, the oxygen molecule is released and can be used for combustion. Using nitrous is one way to stuff extra oxygen into the cylinders. With more oxygen comes the need for more fuel in order to maintain the proper air/fuel mixture and thus the potential for more power from your beloved Ford engine.

Installing A nitrous system on your '05-up Mustang can be fun and rewarding. Nitrous has become a time-honored tradition in the Mustang world-how could it not with its low price, ease of installation, and outstanding power gains? Our test vehicle picked up 78 hp at the rear tires while using the 75hp jet settings.

We tore into an NOS EFI Nitrous System (PN 02121NOS) that was specifically designed for S197 cars. The latest Mustangs utilize a drive-by-wire throttle body, and that prevented NOS from adapting an older Mustang EFI kit for use. S197 vehicles use an electric motor to control the throttle blade-the computer reads the gas-pedal position and sends a signal to the throttle body to control the opening and closing of the throttle blade. Gone are throttle cables and linkage. Yes, we are truly in the computer age. Previous-generation EFI nitrous kits used a micro switch on the throttle body to engage the nitrous only at WOT. The new system doesn't allow such mechanical workings, and this forced NOS to include an electronic control box (window switch) that activates the nitrous above a certain rpm level and turns it off at a predetermined high-side rpm. A wire is connected to the TPS sensor to let the window switch box know the throttle body is at WOT and it's OK to activate the system.

The '05-up Mustangs also utilize a returnless-style fuel system (much like the previous generation modular-powered Stangs). A special fuel-rail adapter is also included in the kit for ease of tapping the fuel system for enrichment. We were happy to see NOS used a stainless steel fogger nozzle (Soft-Plume style) along with stainless nitrous and fuel jets in the kit. Other parts included are a dashboard-mounted arming switch, braided lines, Power Shot nitrous and fuel solenoids, a legendary blue nitrous bottle (with high-flow valve) and mounting brackets, and all the other little pieces. We didn't have to go to the parts bin for anything important-it was a complete kit ready to go. We chose to utilize some bits and pieces that weren't in the kit, however, such as wire loom and special mounting hose clamps-those widgets are not required but recommended to help finish off the kit in a nice manner.

This nitrous kit is a wet system, meaning both nitrous and fuel are sprayed into the intake manifold together. A dry system just has nitrous flowing through the intake, and the extra fuel is added via the fuel injectors. Wet-nitrous systems have received a bad rap over the years, but our experience has always been positive when running a properly working system.

The best advice we can give with wet-nitrous systems is to make sure the bottle pressure is between 900 and 1,000 psi. Adequate bottle pressure ensures the nitrous and fuel atomize correctly as they are sprayed into the intake manifold. Without proper atomization, the fuel can puddle, and that will lead to problems. As long as the nitrous system is installed and used correctly, you shouldn't have any fears.