The ZEX diesel nitrous system is termed a "dry system," meaning no additional fuel is injected into the engine by the kit, as is the case with most gasoline-burning nitrous systems. The reason is simple: a fuel-rich condition generally exists in most diesel engines after a performance programmer tune has been added. It is this extra fuel that we are looking to burn with the ZEX diesel nitrous kit. During our testing on the chassis dyno, we initially sprayed the nitrous with the engine's computer totally stock (OE form). The engine with stock programming saw no power gain with the nitrous. The stock tuning is "clean" and has little, if any, fuel left over for the nitrous to burn.
To increase the power output at this point, more fuel was introduced into the engine electronically through the vehicle's own fuel-delivery system with a SCT Fast-Flash Power Programmer. Hooked into the diagnostic port under the dash, the Fast-Flash walks the operator through a simple process that reprograms the engine's computer to increase fuel delivery. In tandem, we also increased the nitrous-system jet sizes while watching our power levels. It's a simple cause-and-effect relationship: add more fuel and nitrous to make more power. The beauty of the diesel system is your engine makes more power with cooler exhaust temps. Once the existing fuel is burned-regardless of the nitrous injected-you're done, and the excess nitrous exits out the tailpipe. But be forewarned, if you add too much nitrous, your engine will start to lose power. For those folks looking to install the 200hp jet right off the bat without increasing the fuel through the Fast-Flash, we've got news for you. Don't do it. The engine will actually run worse because the excess nitrous will start to extinguish the fire in the combustion chamber. Go slow, and take the steps required to find the right balance of fuel, nitrous, and horsepower.
The ZEX diesel nitrous system features special electronics that perfect the nitrous system engagement. The ZEX diesel nitrous kit's activation switch simply wires into your throttle position sensor (TPS), programs itself to your truck and, once armed, activates at wide-open throttle. This way, you avoid triggering nitrous injection during part-throttle conditions where less-than-peak power can be generated.
 Next, we removed the air cleaner...  Next, we removed the air cleaner to allow access to the intake tube. You can also insert the nitrous injection nozzle in the metal charge pipes on the opposite side of the intake system. |  |  After drilling a hole in the...  After drilling a hole in the intake tube and making certain that debris won't enter the engine, the nozzle's threaded bulkhead fitting was installed. |