When it comes to horsepower, we prefer it cheap and easy, and when it comes to cheap and easy horsepower, there's really no substitute for a dose of nitrous oxide. Although nitrous oxide has a bad reputation as an engine killer, the reputation is largely unfounded and likely started back before the advancement of nitrous technology. Today nitrous oxide, when used properly, is a safe and efficient power adder and is likely the cheapest source of horsepower available for your car. So when the folks at Zex told us they'd developed a nitrous system for the new LX platform cars with a Hemi, we had to try it out.

To safely use nitrous oxide as a power adder, we first need to understand the principles of nitrous oxide. Nitrous oxide itself adds no power to an engine; in fact, nitrous oxide isn't even combustible. Adding nitrous oxide to an engine without supplying the proportionate amount of gasoline (or diesel fuel in diesel applications) will only cause an extremely lean condition, which leads to detonation, heat, and, eventually, engine damage. The chemical compound of nitrous oxide is not a fuel, but an oxidizer, which is utilized to get more oxygen into the cylinders of an engine. Getting more oxygen in an engine allows more fuel to be introduced, thus allowing a more combustible mixture from which power can be derived. So the power doesn't come from the nitrous itself, but from the fuel that is added to combust with the oxygen in the nitrous oxide.

The folks at Zex have taken nitrous-oxide injection to new levels, providing safe, efficient nitrous-oxide kits for both racing and street applications. Their kits for the new Hemi applications meter the fuel and nitrous oxide accurately, preventing detonation and the costly damage it can cause. Additionally, the Zex kits monitor the car's electronic throttle position sensor, so the nitrous oxide and fuel are only added at full throttle. Rather than utilizing a push-button switch to activate nitrous system solenoids, the Zex system incorporates the solenoids and switches into one unit, making the system easy to use and easy to install with fewer parts than comparable systems. There's simply one switch to arm the system, then as soon as the Zex control unit recognizes acceptable engine parameters and application of full throttle, the nitrous oxide and fuel are injected into the engine's air-induction system.

When we say the Zex kit is complete, we mean they thought of everything. All the plumbing, wiring, and necessary components are included in the system, and the instructions are clear and concise. They even thought to include a pipe-thread tap to cut threads for the injector in case we needed it. As it turns out, our induction tube didn't need to be tapped, but it's nice to know they included the tool just in case. The system is tunable in three steps--75, 100, and 125 hp--simply by changing the fuel and nitrous jets in the injector. All the jets are also included with the system. All told, our installation took about half a day and only required basic hand tools.

With our system installed, we were eager to head to Bradenton Motorsports Park for some testing. Of course, we had to see if everything was functioning correctly on the way to the track, and we were impressed by the additional power provided even with just the 75hp jets installed. Once at the dragstrip, we were pleasantly surprised. After our non-nitrous, baseline pass netted a 14.32 in the quarter, we turned on the nitrous for another lap. Though we hadn't really allowed the car to cool down, we still blasted through the quarter at 13.97, gaining 4 mph through the traps as well. After a short cool-down period, our second nitrous pass netted a 13.92 and gained 1 more mph. Unfortunately, a rain shower ended our test session before we could step the nitrous up to its higher power levels, but we're confident elapsed times would have dropped by at least another two-tenths.

All told, we were impressed by the Zex system. It's easy to install, and one of the cheapest ways you can add up to 125 hp to your new 5.7-liter Hemi. Be sure to look for further testing of this system in future issues as we'll step up the power to achieve even better elapsed times.