Nitrous oxide: the chemical compound that invokes fear in the hearts of some while raising the hair on the necks of those who have felt its unruly power. Despite the horror stories, most likely well-exaggerated, nitrous oxide can be as safe as any other power-adder and is, by far, the greatest bang-for-the-buck modification. So, why do so many fear the juice? Presumably, it is due to lack of understanding and a wealth of misconceptions and myths on the streets. Whatever the case may be, the key to running a safe and dependable setup is knowledge. We are going to install a basic wet nitrous system, as well as complement it with a stand-alone fuel supply and a host of accessories for a trick setup that safely adds 125 extra tire-melting ponies.
The subject chosen for the giggle-gas mod is an '03 Dodge Ram with the 5.7L Hemi engine. For some, the stock 345 hp would be sufficient, but when is factory horsepower ever enough? We went with the new Zex Hemi kit, which can be used on any 5.7L Hemi trucks, thanks to Zex's innovative fuel-line adapter that provides a source of fuel for '06-and-later trucks without a factory fuel-rail test port. We've also consulted the expertise of the pros at Aeromotive, so we can feed the beast with race gas while on the bottle, as opposed to pump gas from the tank. The higher octane fuel is for both performance as well as a safety; the increased compression provided by the nitrous thrives on slower-burning fuel, thus making more power, and the high octane will help us avoid detonation.
This system we're installing is more complex than most, yet it can be completed in the typical 20x20-foot garage in less than a weekend's time. However, the basic Zex nitrous systems can be installed on any truck, gas or diesel, in a few hours using common handtools. Whether you're an accomplished pro or a budding gearhead, you can turn your truck into a rubber-shredding freak in a single afternoon, without sacrificing driveability or having the headaches of tuning a supercharger or turbo system.
Part One: Mounting The Hardware First, we carefully chose a mounting location for the Zex
Install -6 hose ends on bulk lengths of -6 fuel line. Be sure to use steel-braided line fo
Select a location for the purge solenoid close to NMU. Before mounting, check that the sup
Reinstall the air intake housing back on the base and route the lines down between the fir
With all of the hardware mounted underhood, start in the bed by mounting the bottle bracke
The fuel pump is gravity fed, so it should ideally mount under the bed and still be clear
Choose a location for the fuel cell, factoring in the routing of the return line, as well
So we can open and close the bottle on the fly, we're installing Zex's remote bottle opene
Use Teflon tape or putty on the NPT thread to avoid leaks.
Ideally, the bottle pressure should be between 900 to 1,050 psi, so to keep our bottle in
Part Two: Wire It Up ToMonitor the system, we're using electric fuel and nitrous pressur
We can pick up fused 12V power and ground for all three gauges by T-tapping into the two w
Rather than mounting a plethora of switches in the cab, we picked up this Nitrous Switch C
We sourced power for the NSC, fuel pump, NMU, and purge solenoid from the post located on
The NMU is triggered by a wide-open-throttle (WOT) switch. Since Hemi engines don't have a
To control the fuel pump, we used the toggle switch supplied in the Zex kit (not used beca
With everything wired, it's time to fill the cell and hook up the bottle to test for leaks
As a precautionary measure, Zex recommends running colder heat range spark plugs to furthe
Before remounting the Shaker hood, we fabricated the purge lines using bulk 3/16 brake lin
The Final Word
On track, performance yielded more than a 1-second drop in quarter-mile e.t. with the truck in full street trim. However, there was more e.t. to be lost, since the factory speed limiter ended the fun early on in the nitrous runs. Extending the speed limiter and adding some sticky rubber could easily turn this mid-14-second street truck into a nasty 12-second screamer, thanks to Zex.
How Much Did It Cost?
Zex Hemi Wet Nitrous Kit:
Zex Bottle Warmer:
Zex Bottle Opener:
Zex Dual Outlet Purge:
Auto Meter Gauges:
Dynotune A/F Gauge:
Dyno tune Nitrous Switch Center:
JAZ Products 1-Gallon Fuel Cell:
VP Racing C12 Fuel (5 gal):
Nitrous (10 lb):
Fuel Lines and Fittings: