Justin Fivella
November 12, 2013

Harnessing The Power

While some might prefer to use their stock wiring harness and simply add a powerful ECU, Pro-M conducted extensive testing on a wide number of Fox-bodies and found that many of them had insufficient wiring harnesses with loose connections and bad grounds, after all, they are getting on in age. Seriously, why waste your time with a powerful new computer if it's going to operate through archaic wiring?

The replacement harness is a plug-and-play affair as it lies in the engine bay and inside the cabin just like the OEM unit does. Pro-M went so far as to offer year-specific harnesses as well, since Fox-body wiring harnesses had slight changes throughout the years.

We can attest to the quality of the harness with accurate wire lengths, hardy looming and all of the Ford connectors that push together with a satisfying click.

7. Jeremy Stanton of Stanton Performance helped with the removal of the tired, old Fox-body harness.
8. After two decades of service and 275,000 miles, most of which was as a highway patrol car, the factory harness was thoroughly cooked.
9. Since we’d previously maxed out our 42-pound injectors, it was time for bigger pumpers, and that necessitated the removal of our Trick Flow upper intake manifold.
10. Be sure to lubricate the O-rings on the injectors before installing them. We ordered the Siemens 62-pound injectors on a recommendation from the EFI wizards at Pro-M since they accurately operate at all duty cycles, even at low loads, which is hard to do with such a big unit.
11. Be careful when feeding the Pro-M harness through the firewall, since it can have sharp edges. With a little patience it will drop down in the stock location.
12. Speaking of patience, you’ll need some, and maybe a little rubber-lube to get the new weather-tight seal to squeeze in place. That’s OK—once it’s in, you’re assured it’s not going anywhere.
13. Inside the car you’ll find high-quality plugs, like this one for the Innovate wideband gauges.
14. Pro-M was ingenious enough to hide all of the relays in one spot for easy replacement. They even label them so there are no questions.
15. The Pro-M harness comes with this insulated blanket to wrap the relays. They’re protected when they’re mounted inside the kick panel where the OEM ECU once was.

The 92mm Monster

Since there was no way we were going to waste such a powerful computer and harness on an insufficient MAF, we stepped up to the Pro-M 92mm unit that is seriously wicked. The unit features cast aluminum construction with a bell-mouth inlet that removes the sampling element from the opening for maximum flow.

The air hog is capable of handling 1,500 hp and also features a unique 360-degree sampling area that averages the MAF signals for the most accurate readings. The unit has a connector that plugs into the Ford-style harness and even comes with a conical air filter.

Powerful Pipe

When Pro-M asked that we smooth the airflow into the MAF for the best signals (since turbulent air inside a MAF is highly undesirable), with on of their wicked 92mm MAFs, we also decided it was a good time to call Anderson Ford Motorsport for one of their infamous Power Pipes. These legendary cold-air intakes straighten out the incoming path of air into the blower by placing the MAF and filter inside the inner fender for a cooler, denser air charge. They're often imitated but never duplicated, since Anderson has been at it for years. Prior to the dyno we were already certain there were serious gains on the horizon, but we really had no idea (more on that later).

The Power Pipe smooths the incoming air and also relieves the restriction forward of the blower. Uncorking this section is generally good for a gain 1-3 psi of boost on blower applications without spinning the blower any faster. Seriously, it's more boost and more power simply by relieving restriction.

The unit came with all of the necessary hardware along with the high quality rubber couplers and detailed installation instructions. We'll admit that measuring and enlarging the fender-well hole wasn't easy. Take your time and measure several times before trimming.

Installation Process

Considering the undertaking of removing and replacing the entire fuel injection system on a Fox-body, the process was rather easy. We found it best to take our time and remain methodical throughout the process. Removing the factory harness was slow going since the arthritic clips were old and brittle. Nonetheless, after an hour or so the entire stock stuff was out and the new Pro-M harness was roughly laid out in the engine bay, giving us an idea of what we were after.

Pushing the harness through the firewall was tricky, as was mounting the new weather seal in its place, but some patience and a little rubber lube went a long way. After a solid half day, the harness was in the car and we were ready for blast-off.

While the install was rather painless, it did takes us a few attempts to get our laptop to communicate with the appropriate drivers for both the ECU and the wideband gauges. After a little IT work, we managed to sync up and free-air calibrate the MTX-L widebands and got the Pro-M ECU talking with the laptop.

16. Astute readers will note that Pro-M has gone to great lengths that no other aftermarket ECU company has in using a custom version of the genuine Spanish Oak ECU, similar to the ones in the S197 Three-Valve Mustangs, but with tons more brain power and Pro-M only features. The Visteon processor bringscapabilities to the Fox that were never previously possible.
17. When we say Pro-M is detailed, we mean it. Even down to the wires, which are individually marked so there’s no problems during the install. This is the passenger-side wideband gauge wire.
18. We opted to use the Innovate MTX-L wideband gauges with the Pro-M ECU since having the computer run off the widebands brings a whole new level of tunability.
19. Since the new ECU monitors each bank of cylinders, you’ll need to run a pair of widebands, and since it’s side specific, a little tape on one side helps from getting them mixed-up.
20. Don’t forget antiseize on the new O2 sensors or you’ll be sorry later.

The Software

Even though the pre-installed tune from Pro-M was surprisingly accurate, we dove in feet first with the software. We found it easy to use once we stared at it for a minute and quickly navigated the working pages, real time data logging and monitoring tools. A call or two to the helpful tech line at Pro-M got us answers to additional questions, and before long, we were adjusting the 3D graphs of our load and lambda fuel tables against our spark trim.

The real-time data-logging might not offer a screen play back mode like other stand alones, but we found is easy to view our logs in the included graph form. Another note about the capabilities of the ECU: Tuner extraordinaire and all-around Mustang badass Drew Wallace of AED in Shingle Springs, California, noted that when zooming in on the logs, the graphs remained startlingly clear. He attributed this to the fast sampling rate of the ECU and was beyond impressed.

The real-time data logging was helpful during our dyno pulls when we encountered a lean condition that was ultimately traced backed to the maxed-out stock fuel rails and lines. While monitoring the injector duty cycle, we noticed our massive Siemens 62-pound injectors were pegged out. Simple math revealed that while the injectors were sufficient, they were starved by the stock lines and rails. Logging in real time kicks ass!

We also found the pot-box to be helpful during tuning sessions since it allows for tweaks to the tune with a simple poke of the up and down arrows. Instead of rotating between the computer and your widebands, you can simply tap the arrows to fatten or lean out the mixture as you watch the wideband gauges in real time—no hunting for certain boxes and manually adding in a number.

The dual internal memory of the ECU was also nice. As we explored different parameters of the tune we could save our changes on a temporary memory portion. If it was something we liked, we could write it to the permanent memory; if it wasn't a keeper, we reverted back to the previous map without having to constantly write to the ECU.

21. Note the quality Ford connectors on the new harness—this sucker fits like factory!
22. Although the Pro-M has a sophisticated internal ignition coil control with four individual processors that actually averages the firing events to makeup for the shaft play in the distributor, it still connects to the factory TFI module. Note the new ignition spout connector that is easily disconnected.
23. All of the connectors on the new harness are better than factory units and every wire is cut and loomed to precise lengths.