Nitrous Made Easy: Wiring & Progressive Control from Nitrous Outlet

If you were to take a poll among racers at the track regarding their least favorite task when working on their car, wiring would probably be right at the top of the leaderboard. If you have to add or change wiring on a late model performance car for upgrades such as nitrous oxide, you could have a headache on your hands. Nitrous Outlet has stepped up to simplify wiring your modern muscle car for nitrous with its Pro Wiring Harness, and they make controlling that power very manageable with its ProMax nitrous controller. When used together, your nitrous system becomes as simple to install as it does to use.

Our Project Red Dragon Trans Am has been equipped with a Nitrous Outlet plate kit for several years. This wet nitrous system has pushed the car into the 10-second range with just a camshaft swap and supporting modifications. The wiring for the nitrous system is still original dating back to when it was installed and was in need of an update. With the power we plan to make, it was also time for a more modern progressive nitrous controller. The ProMax was a great choice since it’s designed to work within the Nitrous Outlet ecosystem, including the Pro Wiring Harness.

The current nitrous wiring on the Red Dragon works without any issues at all, however, it's a bit "busy" and could use a tidying up.

Wiring Done Right: The Pro Wiring Harness

Wiring a car for nitrous oxide can be a tedious and intimidating task, and if you don’t get it right, it can cause some major headaches and electrical gremlins that will manifest themselves at the most inopportune times. The basis of the Pro Wiring Harness comes from years of experience that Nitrous Outlet and its staff have accumulated. They have seen the issues wiring a nitrous system can cause anyone, so the best solution in their eyes was a professional-level harness pre-made for any application.

According to Jonathan McDonald from Nitrous Outlet, the wiring is often overlooked until the last minute, and that leads to a range of issues.

“Proper wire type, gauge, termination, and connector usage are paramount to the function of your nitrous system. We’ve seen residential home wire, wire nuts, 22-gauge speaker wire to power the solenoids, wrong or no relays – the list goes on. However, the most common issue we face is improper or insufficient grounding in the wiring system.”

The first thing you notice about the Pro Wiring Harness is how high-quality it feels.

The Pro Wiring Harness came to be as a way to provide nitrous users a means to cut down on the time it takes to wire a car correctly. For race teams or shops who install nitrous systems, the Pro Wiring Harness allows them to put only one tech on the job to install nearly any nitrous system with its straightforward design. And for the DIY’er, it eliminates a tedious, daunting, and problematic part of the install.

The Pro Wiring Harness has a lot of provisions built into it that allows it to be used with all the major nitrous system components you would need.

Creating a wiring harness isn’t rocket science in how it goes together, however, there is a high level of thought that goes into the design. Nitrous Outlet could have gone a one-size-fits-all route, however, the team decided to take the time to ensure each of its Pro Wiring Harnesses would live up to the name with a professional fit. By going the extra mile, Nitrous Outlet has cut down on fitment issues and that eliminates the headaches that those who install nitrous kits encounter.

“We start the harness development process by bringing a car into our research and development shop. After looking at the layout of everything, we map the routing and component placement, take all the needed measurements, and create a harness layout board. During this process, we also create full-color diagrams that are shipped with each harness. We then make the first harness and disassemble the car for installation. Part of the process is the documentation of the whole disassembly and installation. We create a detailed picture instruction manual that goes with each harness for the application it was designed for,” McDonald explains.

Included with the kit is a nice instruction manual that is fully illustrated along with the additional connector ends you'll need.

Putting so much time into designing a premium wiring harness would be a waste without using quality components right? Nitrous Outlet uses premium insulated and stranded copper automotive wire as the base material for the Pro Wiring Harness. The wire is the proper gauge for the circuit amp load that it is being used for each portion of the harness. To make sure the harness has the best connection quality, weather resistance, and amperage capacity, Nitrous Outlet uses Deutsch DT connectors in the Pro Wiring Harness.

“With some applications, we use Delphi Mil-Spec connectors at the firewall pass-through. For abrasion resistance and looks, we utilize expandable mesh sleeving, too,” McDonald adds. “All power and ground connections for the harness are routed back to the battery, requiring one battery positive and one battery negative connection. We utilize premium high-amp automotive relays in our relay block for proper power control, and each circuit is properly fused in a single fuse block. Terminations for the switch panel are made so that you can run any of our available vehicle-specific switch panels.

The connectors that Nitrous Outlet uses gives the harness an OEM feel.

Nitrous Outlet has two different versions of the Pro Wiring Harness: one can be used with its WinMax Window Switch, and the other with the ProMax Progressive Controller. The harness allows for the WinMax and ProMax to be mounted in the glovebox or the console of the vehicle.

A nitrous system can have a lot of accessories in use depending on the complexity of the system; Nitrous Outlet took all of that into consideration when designing the Pro Wiring Harness.

“The Pro Wiring Harness has a lot of provisions built into it that allow it to be used with all the major nitrous system components you would need. We included the ability to run two stages of nitrous with the harness, a connection for a switch panel, a purge system, dedicated fuel system, a bottle opener, a bottle heater, various sensors, and other items,” McDonald explains.

Every wire is labeled on the Pro Wiring Harness so there’s no guessing as to what each wire is intended for.

Nitrous Outlet wanted to ensure the Pro Wiring Harness was a comprehensive solution for wiring a variety of nitrous systems.

“The Pro Harness is as close to plug-and-play as you can get. However, some connectors cannot be assembled until after installation of the harness has been completed. We send the required connectors and terminals to do so and outline the connector assembly in our instructions. We also send all the needed mating connectors for the controller, solenoids, and other parts,” McDonald says.

Controlling The Power: The ProMax Nitrous Controller

The introduction of nitrous oxide into your engine creates a violent chain of events within the combustion chamber that leads to the potential for significant upticks in horsepower. That power moves through the driveline to the rear tires, so it can be hard to manage if it comes in all at once. The job of a nitrous controller like the ProMax is to allow for the nitrous to be progressively added so the power can be used optimally via power management.

What a progressive nitrous controller is not is a device that limits horsepower; rather, it acts as a traction control device in a sense. The power of the nitrous is brought in on a linear curve to make sure a vehicle’s suspension can absorb and use the power, rather than spin the tires.

The ProMax Nitrous Controller comes ready to wire from Nitrous Outlet.

The ProMax, like most nitrous controllers, works off of a ramp concept in how the nitrous is ramped in. According to McDonald, you want to be very diligent with how you use the ProMax and the nitrous ramp.

“You want to keep your progressive ramp as short as possible to prevent unneeded solenoid wear and to prevent nitrous to fuel ratio issues. If you think about it, if the nitrous is at 900 psi and fuel at 45 psi, how much more nitrous is being injected with every pulse?”

The ProMax is almost as simple as a modern smartphone to use. Conceptually, Nitrous Outlet wanted to create a comprehensive controller that was both user-friendly and would keep your engine safe. The ProMax can be programmed via a laptop and only needs a tach and TPS signal for basic functions, but it has the ability to do much more. It comes in several different kit configurations based on your needs, so you can add on to the system as your nitrous setup grows in complexity.

“The ProMax is available as the box only, the box and touchscreen, or the box, touchscreen, and sensors in a complete package. We also have a suction cup mount available for the optional touchscreen. The touchscreen for the ProMax allows you to switch on the fly between five progressive ramps that you can have set from radial prep to a dirt road and everything between. It also displays system status, allows all setup to be done in-car without a laptop, and can display five different input values such as TPS percentage or RPM, which you can select,” McDonald says.

What makes the ProMax a great fit for the Red Dragon and virtually any other nitrous-fed vehicle is the wide range of options it has.

The ProMax has the capability to control two independent stages of nitrous without AFR (air/fuel ratio) control, or a single stage with AFR control. Inside the unit there are two 70-amp drivers that eliminate the need for external relays, which cuts down on the amount of wiring needed. The unit also has outputs for timing retard and can trigger other devices like a Lingenfelter LNC or an MSD Grid. There’s also a built-in transbrake interrupt that removes the need for another relay in your wiring.

We opted for the kit that includes the touchscreen so we can make changes in the lanes to the tune-up and monitor the nitrous system in real-time.

As stated earlier, the ProMax can run with just a 12-volt power supply, ground, TPS, and tach input, but you can add many other inputs to give you more control while adding safety to your nitrous system. McDonald explains a few of the other inputs that you can use with the ProMax.

“There are inputs available for two nitrous pressure sensors, one fuel pressure sensor, and two widebands, such as an Innovate or AEM, MAP, and VSS. The addition of these inputs allows you to activate optional operational ‘windows’ for safety in how the system will function. The system will work from low pressure all thw way up to around 100 psi. This opens up more options for setting up your progressive ramp. The types of ramps you can set up include time, RPM, TPS, MAP, and vehicle speed based.”

Tuning an engine to make big power with nitrous has become much simpler over the years with the knowledge racers have gained and the technology that’s become available. Having a tune-up that’s both fast and safe for your engine has been simplified, and the ProMax helps with the safety side of things. Using the AFR control option opens up a much larger window for users to prevent catastrophic engine failure when the nitrous is flowing.

The suction cup mount holds the display firmly in place. The included cable gives you plenty of freedom as to where you can mount the display.

“The AFR control is simply a method of control that will actually pulse the solenoids to maintain a target AFR that you set. If it starts drifting lean, it will pulse the nitrous solenoid to bring the mixture back into range. If bottle pressure drops and you start drifting rich, it will pulse the fuel solenoid to bring the mixture back into range. If things get too far off with your AFR the controller will stop spraying to save the engine. This is a great insurance policy to help keep your engine safe,” McDonald explains.

The optional touchscreen for the ProMax allows you to change on the fly between five progressive ramps that you can have set from radial prep to a dirt road and everything between.

One of the nice features of the Pro Wiring Harness and the ProMax is the amount of documentation you recieve. If you’re doing an installation on a vehicle that has never been wired for nitrous before, the instructions tha Nitrous Outlet provides are top-notch. The Pro Wiring Harness installation instructions have photos for each step that illustrate and explain exactly what you need to do. They also include comprehensive instructions on how to assemble the Deutsch connectors that are included to finish the harness.

For the ProMax, you receive detailed wiring diagrams that show exactly how to hook up the unit for both single and dual stages of nitrous. The diagrams are marked what color wires go to things like your various sensors, transbrake, and nitrous system accessories. There’s also a handy chart in the directions that has all of the wire colors, their gauges, and what they are used for.

Since the Red Dragon already has wiring in it for the current nitrous system and controller, the installation will be a bit more complex. The plan is to install the Pro Wiring Harness and the ProMax when we install the Nitrous Outlet standalone fuel system in the future. This way we are only doing one big surgery on the car and everything will be installed one time, where it’s needed.

Cleaning up the wiring for the Red Dragon with the Pro Wiring Harness will help the engine bay look more presentable and make troubleshooting much easier. Likewise, the addition of the ProMax Nitrous Controller is going to make tuning the nitrous system in different conditions a snap while providing a plethora of additional functions.

The next step for Project Red Dragon will be a full standalone fuel system from Nitrous Outlet to compliment the nitrous system, followed by on-track track testing. Stay tuned to see what elapsed time and speed improvements all of these upgrades will net when we turn up the wick in the coming months!

Article Sources

About the author

Brian Wagner

Spending his childhood at different race tracks around Ohio with his family’s 1967 Nova, Brian developed a true love for drag racing. Brian enjoys anything loud, fast, and fun.
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