How to Add Nitrous to Your LS-Powered Vehicle

10 min read

How to Add Nitrous to Your LS-Powered Vehicle

10 min read

Horsepower: more is always better, and the easiest way to get more horsepower is with nitrous oxide injection. If you have an LSX engine under the hood of your project, Nitrous Oxide Systems (NOS) has some great options to get you squeezing the juice easily and safely.

The biggest factor when determining which NOS nitrous system is best for your project is the induction and engine management types. "Wet" or "dry?" Plate or nozzle? "Wet" systems inject the necessary extra fuel at the same place as the nitrous oxide. "Dry" kits only inject nitrous oxide. Fuel enrichment when on the juice is injected via the EFI system. Plates or nozzles can be either wet or dry.

Selecting the right NOS injection method for your LSX-swapped project can get confusing, so here's a handy flow chart to help you make the best choice.

If your LSX-swapped project has a carburetor, a tried-and-true "wet plate" is for you. These systems sandwich between the carburetor and the intake manifold and are the easiest way to add 100-250 horsepower (though systems supporting a 500 horsepower boost are available). NOS offers plates that fit Holley 4150, Dominator 4500, and even spread bore flanges. Wet plate systems draw fuel from the existing carburetor's fuel supply, so you need to make sure your fuel pump, lines, and regulator are up to the task of supplying the extra fuel necessary. The system is simply activated by a switch (or progressive controller).

If your LSX is topped by a Holley throttle body injection system that supports nitrous control (such as Holley's Super Sniper or Terminator X Stealth), then a "dry plate" is the way to go. Like a carbureted "wet plate," the nitrous is injected between the intake manifold and the throttle body. However, the fuel is injected via the Holley EFI throttle body's injectors. Available systems add up to 600 horsepower! The system is controlled with settings made to the Holley EFI system.

If you have an OEM-style intake manifold on your LSX engine, a throttle body "wet plate" is an option. It installs behind the throttle body and injects both nitrous and fuel into the plenum of the intake manifold. These systems are typically used with factory engine management systems that don't support nitrous control. Just like a carbureted wet plate, fuel is siphoned from the existing fuel injection system. Jetting is included for up to 150 additional horsepower. Control is via a wide-open-throttle switch or a stand-alone progressive controller. A disadvantage is fuel and nitrous distribution can be uneven, as most EFI manifolds are only designed to flow air, not fuel.

For those using a factory EFI system for which there isn't a "wet plate" option, a "wet nozzle" is another method. Like a wet plate, the wet nozzle injects fuel and nitrous at a single point--usually upstream of the throttle body. The existing fuel system needs to be up to the task, as fuel to accompany the nitrous is drawn from the same system as the EFI fuel injectors. Control is separate from the EFI system as well. Wet nozzles are subject to the same fuel and nitrous distribution concerns as wet plates, but sometimes they're the only option.

To avoid the pitfalls of uneven nitrous and fuel distribution, a "direct port" system is the answer. Available in wet or dry nozzle configurations, direct port setups inject nitrous (and for wet systems, fuel) down each intake manifold port. Jetting can be tailored for each individual cylinder, and the nozzles can even be "hidden" on the bottom of the intake manifold--if you like keeping an ace up your sleeve.

The most elegant solution for LSX nitrous injection is a dry plate designed for your specific intake manifold. Since the Holley EFI system controls the system, the proper fuel is injected when needed so the plate only flows nitrous. NOS offers some excellent plate systems for Holley's most popular intake manifolds for LSX engines, including the Holley Hi-Ram (both LS and LT) and Sniper EFI fabricated manifolds.

NOS dry plates are designed to inject nitrous directly down the intake ports of popular Holley EFI intake manifolds, such as the Holley Hi-Ram. Since they install between the plenum cover and the lower manifold, installation is extremely simple. It's a simple bolt-on install. No drilling or tapping!

What's great about nitrous oxide injection? It's your engine, but now with more horsepower on demand! Nitrous is only there when you want it, and leaves your engine alone when you don't need it.

Before hitting the nitrous enable button for the first time, you need to make sure your fuel system can support the extra fuel needed when on nitrous--plus an extra margin of safety. Fortunately, Holley's offers countless fuel system options in including in-line and in-tank fuel pumps and modules to feed any horsepower level.

NOS offers complete kits (such as this system for Holley's Hi-Ram manifold) as well as individual components and accessories to bring the squeeze to your LSX-swapped project.

"I already have a power adder. Can I use nitrous?"
Do you like horsepower? Then you bet your bottle you can add nitrous to your boosted LSX! Blown cars (especially turbocharged) benefit from the instant, low-end hit of nitrous. Besides helping boosted cars spool up faster, the cooling effect of nitrous is like a super-intercooler that chills the charge and reduces the risk of detonation.


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