Evan J. Smith
Freelancer
February 24, 2017

Modern performance enthusiasts expect perfection. We want our engines to fire on the first crank, to idle nicely, and to produce wicked power—all with the precision of a Swiss watch. No matter if you are running high compression or boost or spraying a 400 shot, you demand dependable power when you mash the gas.

Of course, once you take your vehicle beyond stock, the responsibility falls on you (or your tuner) to keep the drivability parameters in check. Having the proper air/fuel ratio is important for performance and durability. Miss on the tune and your fun factor goes in the toilet. Thankfully, modern wideband O2 sensor technology provides the tools to let you properly tune your engine.

For decades, Innovate Motorsports has led the way, producing affordable and accurate wideband O2 monitoring systems. One of the newest offerings is the PSN-1 Power Safe Nitrous Bottle Pressure and Wideband Air/Fuel Ratio Gauge Kit.

As “Power Safe” implies, the gauge is designed for nitrous users. The kit is all-inclusive and features a multitude of functions, so you end up with a great-looking display, a nitrous safety override, wideband air/fuel ratio monitoring with rpm window switch, and four channels of data-logging data with powerful LogWorks PC software. Along with many other features, it can display air/fuel ratio or lambda, inHG, PSI, kPa, or BAR.

In the box you will also find Innovate’s MTS serial in/out cable (for use with other Innovate and third-party MTS-enabled devices to add additional logging channels). In lay terms, the gauge provides safety; it can turn off your nitrous (or prevent it from activating), unless certain parameters are met. These include the rpm window switch, which allows the nitrous to turn on when the engine is within the preset rpm range (adjustable in 10-rpm increments). It monitors air/fuel ratio so it can close the nitrous solenoid during lean conditions, and it uses the bottle pressure sensor to ensure that bottle pressure is in the proper range.

“While some tune-ups are more forgiving than others, nitrous isn’t one of them,” says Mark Gearhart of Innovate Motorsports. “Catastrophic events happen when things go wrong while spraying nitrous—from broken engine parts to grenaded intake manifolds.”

In the old days, you’d make a short hit, then pull the plugs to inspect your running condition. And although looking at plugs in a nitrous car is never a bad idea, the PSN-1 gauge properly monitors and records those important parameters when you are shooting the juice, so you are arming yourself with data. All this data is packed into this small gauge that is sized in the standard 2 1/16-inch package that fits in most gauge pods. Even so, the PSN-1 gauge does so much that it can literally replace a variety of systems.

Enthusiasts will most definitely like the user-configurable OLED screen, which has a nice display for bottle pressure and air/fuel ratio. Displays include AFR, lambda, PSI, kPa, or BAR and there is also an rpm-activated shift light built in. Mind you, this kit is all-inclusive, so once you install it there is no need to use a PC for configuring or downloading.

Next on the list of cool features is the nitrous safety cutout switch, which lets you designate the window of nitrous operation based on air/fuel and/or bottle pressure. “The PSN-1 gauge is a cheap piece of insurance that can quickly and easily shut off your nitrous kit if your air/fuel ratio rises above the user-selected threshold,” says Gearhart. “A lean situation like this can be caused by a multitude of reasons, like a stuck solenoid, improper jetting, or a failed fuel pump.”

So this gauge gives you the ability to have such extreme performance, drivability, and reliability through precise tuning using wideband O2 sensors to monitor lambda (air/fuel ratio). Keeping your engine in the sweet spot prevents detonation and other engine-damaging conditions.

It is important to note that the wideband sensor is compatible with most popular fuel types, including leaded and unleaded, diesel, E85, and a few others. Users can even calibrate the O2 sensors. The kit utilizes the patented DirectDigital wideband sensor control to provide the ultimate in sensor accuracy.

We wanted a closer look, so we headed to Coastal Dyno in Tampa, Florida, to check out a PSN-1 install on a Shelby GT350 that made 460 rwhp and 365 lb-ft of torque in stock trim. Once the car was fitted with long-tube headers, a JLT cold-air intake, a custom tune by Coastal Dyno (running on E85), and a 100-shot, the output jumped to 617 hp and 577 lb-ft of torque.

Installing the Power Safe gauge gives you piece of mind—and that’s what the owner of the 2017 Shelby GT350 was looking for. The Ford Mustang was perfect for the Innovate Motorsports PSN-1 gauge, and the guys wasted little time getting it hooked up.

Coastal tech Steven Harris handled the job, which took only a few hours. Like we stated earlier, the kit is all-inclusive. However, you will have to mount the gauge, so you will need a suction-cup mount or a gauge pod. We went with an A-pillar mount, which the shop had ordered prior to our install.

Overall we were impressed with the look and the operation of the gauge kit. The digital display is easy to read, and scrolling through the various screens requires a simple push of a button on the gauge face. The gauge also features a modern look, so it’s right at home in any new Ford, and you can customize it with the optional faceplate and bezels included in the kit.

1. It’s not every day you see a Shelby GT350 with nitrous oxide, so we figured it was a perfect recipient for the Innovate Motorsports PSN-1 Power Safe Nitrous Gauge.

2. The kit comes complete with everything you need for installation.

3. A Bosch LSU 4.9 wideband oxygen sensor works the patented DirectDigital wideband sensor control to give you deadly accurate lambda readings.

4. In addition to the multitude of functions, Innovate Motorsports includes black and silver interchangeable faceplates and bezels to let you customize the look of the gauge.

5. Tucked neatly in the trunk of the Mustang are twin 10-pound nitrous bottles.

6. While not the most likely candidate for nitrous, this owner had no problem spraying his GT350 with a 100-shot of juice. The addition of a few aftermarket mods and nitrous gives this Shelby GT500-like output.

7. The first order of business was disconnecting the battery; then we removed the driver’s side interior rocker and kick panel.

8. Steven Harris of Coastal Dyno removed the factory A-pillar trim panel.

9. The first item we installed was the 1,500-psi nitrous bottle pressure sensor. This sensor can be installed directly to the bottle. However, since we are running two bottles, we located the sensor at the Y-block fitting in the trunk.

10. We removed the rear seat in order to run the wiring from the bottle pressure sensor up to the gauge.

11. Next, we raised the car and installed the Bosch wideband oxygen sensor in the exhaust.

12. The kit comes with plug-and-play cables so making the connections is easy. This cable connects the oxygen sensor to the gauge.

13. After connecting the oxygen sensor cable under the car, we fed it up the firewall and into the interior.

14. We then drilled a hole in the firewall to connect the rpm signal wire. At this time we also wired in the Innovate single device relay (not shown).

15. Here’s the part we all love, installing the gauge. Harris fed the wiring through the new A-pillar trim panel, and then he carefully popped it into place.

16. It is important not to pinch any wires when doing this procedure.

17. We stuck with the black face and black bezel on our PSN-1 Nitrous Safe Gauge.

18. There were a few more connections to make. Harris wired the “key-on” and the ground, and he attached the remaining wire connections.

19. The moment of truth came when we hit the ignition and the gauge came to life. The PSN-1 gauge system gives you the tools to accurately monitor and enhance the performance of your nitrous system. The Power Safe technology can even be programmed to disable your nitrous solenoid to keep your engine safe.

20. The gauge is user-programmable and can actually shut off your nitrous using a nitrous safety cut based on air/fuel ratio and bottle pressure references. The nitrous cut feature comes in handy if the engine suffers lean air/fuel conditions or minimum bottle pressure.

21. Among the many features, the gauge is configurable for linear 0-5v analog output for wideband oxygen use with piggyback or standalone ECUs, as well as external data loggers.

22. Here is the PSN-1 with the display in bottle pressure mode. The system is equipped with a 1,500-psi nitrous bottle pressure sensor, as well.