On The Dyno
We gave GTR's Dynojet chassis dyno a serious workout during our quest for naturally aspirated power gains and major performance increases using nitrous oxide, putting no fewer than 24 runs on Abraham Becerra's '06 Mustang GT over the course of two days. As usual, baseline tests were done initially to determine the 'Stang's rear-wheel power in bone-stock trim, followed up by dyno runs after Ricardo Topete installed each bolt-on. An rpm window of 2,000-6,200 was maintained for the initial dyno pulls, as well as those with the bolt-ons.
 Installing a cold-air-intake...  Installing a cold-air-intake system is basically a 30-minute exercise. The GMS system bolts directly in place using basic handtools (the kit includes a new gasket and screws for securing the factory mass air sensor to the tube); it has a clean fit and finish on an S197's Three-Valve engine. |  The Granatelli Motor Sports/Zex...  The Granatelli Motor Sports/Zex nitrous-oxide system includes all of the pieces shown in this photo (AN -4 braided line; fittings; nitrous/fuel solenoids and jets; arming switch), including a GMS rpm-activated, dual-window switch; fuel-rail adapter; and bottle-pressure gauge. |  A good rule-of-thumb to follow...  A good rule-of-thumb to follow when installing nitrous, or even stereo equipment, is to take advantage of a Mustang's natural holes for passing lines, wires, and such between two points (in our case, from the trunk to the front of the vehicle). After removing the trunk carpet, we found a small grommeted opening on the driver's side that is perfect for running the AN -4 nitrous feed line from the bottle to the solenoid. |
Our test stocker responded well to all of the parts in our selection, showing impressive but not overwhelming naturally aspirated power-and-torque gains that are on par with data we've recorded in similar bolt-on parts evaluations for stock S197s. As we expected, the addition of a Granatelli Motor Sports/Zex cold-air/nitrous-oxide system proved to have the biggest impact on the stock Three-Valve, taking the 'Stang's rear-tire horsepower close to the 380 mark, with more than 450 lb-ft of tire-shredding torque.
 Ricardo mounted the nitrous...  Ricardo mounted the nitrous and fuel solenoids on the rear panel of the CAI's shield. |  Since we are working with...  Since we are working with a wet nitrous system, a fuel source had to be plumbed directly into the Zex fuel solenoid. To accomplish this connection, we used a Granatelli Motor Sports fuel-rail adapter for '05-'09 Mustangs with returnless fuel systems. The billet adapter sits between the fuel rail and fuel-rail sensor, and allows us to run the supplied length of AN -4 braided line between the rail and the fuel solenoid for the nitrous unit. |  Nitrous and fuel pills are...  Nitrous and fuel pills are included with the GMS/Zex nitrous system. The kit will support as much as 300 hp, but we dialed-in a 100hp blast (0.052 nitrous jet/0.030 fuel) as it's Abraham's first experience with a power adder. |
 Although the nozzle and solenoids...  Although the nozzle and solenoids are dead giveaways to the nitrous system, we felt it was important to route all of the wiring involved with this type of installation in a neat, logical, and stealthy manner. Since a main power source is located on the passenger side of S197s and we mounted nitrous and fuel solenoids on the driver side of the engine compartment, Chris ran a power wire from the fuse center into a relay and across the radiator to the solenoids and GMS rpm-activated, dual-window switch. |  Chris recommends do-it-yourselfers...  Chris recommends do-it-yourselfers follow the instructions closely when setting up the dual-window switch to trigger and shut down the nitrous hit. |  The GMS switch is fully programmable...  The GMS switch is fully programmable from 1,000 to 15,000 rpm, and uses both an injector-pulse reading for rpm (taken from a fuel-injector wire) and throttle-position (measured by tapping into the outside TPS wire) to control the nitrous. |
 Proper fuel volume and timing...  Proper fuel volume and timing are critical to achieving success with nitrous, but bottle pressure (the actual pressure in psi of nitrous oxide inside its container) is also extremely important. Increasing pressure inside a nitrous bottle is done using heat, and Zex offers a neat bottle warmer that does the job quite well. Since a bottle warmer (and remote opener) are coming later for Abraham's setup, we relied on the natural warming process, raising the bottle pressure to the recommended 950 psi by letting the bottle sit in the Southern California sun until it was time to test. |  Your tech editor selected...  Your tech editor selected a small, open area in the headlight-switch panel as an appropriate mounting location for the nitrous system's arming switch. With a flip of this switch and mash of the throttle, Abraham's Pony will be under the influence of nitrous once the tach hits three grand! | |