Why the Pro-M EFI System Is Right for You and Your Vehicle

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The Pro-M EFI Powertrain Management system is an OEM quality, Mass Air, sequentially fired, port fuel injection system, with full ignition control and transmission controls. The Pro-M EFI system provides a combination of drivability and quality typically only found in the OEM, combined with a level of performance typically only found in the aftermarket. It is truly the best of both worlds.

It is easy to install, simple to use, and allows for customization of virtually every electronically controlled powertrain function.  However, tuning is neither required, nor recommended. Tune if you want to, not because you have to. The money you will save by not going to the tuning shop will pay for your Pro-M EFI system. No one else can make this claim.

We accomplish this by adhering to the following principles:

  • Use “Load” to calculate both the proper air/fuel ratio (Lambda) and the proper spark advance, as well as a host of other powertrain functions, under all conditions for both accuracy and flexibility.
  • Use “Closed Loop” feedback for fuel, spark, idle control, water/meth injection, and anywhere else possible.
  • Provide an excellent “base” calibration that will run any engine at an OEM level while still allowing for user modification to any parameter in an intuitive user interface
  • Provide OEM level controls for popular features such as nitrous oxide, water/methanol injection, traction control, 2 step, launch assist, flex fuel, and more.
  • Use only top quality components.

We will touch on each of these below.

1) Pro-M bases engine management on a value known as Load.

Though this may sound complex, engine management is not as complicated as you may think. Basic engine management boils down to two things:  Lambda (Air/Fuel Ratio) and Spark Advance.  The proper value for each of these can only be determined if we have an accurate value for Load.

It is important to understand that the proper a/f ratio, and the proper spark advance are dictated by nothing other than Load. Any other method is just guesswork.

Load is simply the air mass being ingested by the engine divided by the engine's potential for air mass. The engine's potential for air mass is calculated using the engine's displacement and the RPM. When using a mass air based engine management system, the ingested air mass is constantly obtained in real-time from the output of the mass airflow sensor.  Therein lies the beauty of a mass air system – The single most important values for proper engine control is directly metered by a sensor and not derived from multiple other values.  The Load calculations are done for you by the Pro-M EFI PCM.  All you need to do is enter the proper information into the calibration: the MAF transfer function, the engine's bore and stroke, and the number of cylinders.

But doesn't the combination of engine parts dictate the needed a/f ratio and spark advance? Indirectly, yes it does. But that combination of engine parts is going to result in some amount of airflow, which will result in a certain value for Load, and that is what really matters. It does not matter how you get that airflow. All that matters is what you get.  So indirectly, using this method, your a/f ratio and your spark advance are inherently customized to your combination of engine parts, simply by virtue of how it works.

It makes no difference what engine you are using.  It makes no difference what heads and intake you have, what cam(s) you use, what you have for an exhaust system, or how many times you decide to change these things.  It doesn’t even matter if you add forced induction or change the amount of boost on existing forced induction application.  If the PCM knows your displacement, RPM, and your ingested air mass, it knows Load… and if it knows Load, then it can accurately control fueling and spark advance. It is that simple… 

This is how all OEM systems work. The OEM systems that do not use mass air, generate their volumetric efficiency calculations by mapping out the engine with a mass air meter, then use that to determine Load. They can do this because they use the same engine combination over and over again but understand that every OEM management system uses Load.

The OEM method for using Speed Density is obviously not practical in the aftermarket since every engine will be different. Despite that, Pro-M EFI is the only aftermarket engine management system that uses Load.

2) Closed Loop Feedback ensures that what you want is what you get.

Closed Loop means the PCM is monitoring a particular engine variable and comparing it to the desired target.  When there is a discrepancy, the PCM will automatically make corrections until the actual monitored value matches the target.

You may be familiar with the closed loop fuel controls used at idle and cruise in factory vehicles equipped with narrow band O2 sensors.  For example, the target air/fuel ratio at idle is typically 14.7:1, but for a variety of reasons, the actual a/f ratio may not be at the targeted value.  The narrow band O2s tell the PCM that the mixture is not correct.  Operating in closed loop, the PCM makes a correction to the fueling until the O2s detect an actual ratio of 14.7:1, thus matching the target. 

In recent years, OEMs have started to use closed loop feedback for fueling at all times (not just at idle and cruise) by replacing the narrow band O2s with wide band sensors that can accurately measure a much broader range of a/f ratios targeted under a variety of operating conditions. Pro-M EFI uses two wide band O2 sensors (One in each bank) to provide the most accurate fueling possible under any operating condition.

Additionally, the Pro-M EFI PCM uses an adaptive strategy to “learn” your engine's fueling needs. This results in the most accurate fueling calculations in the industry.

In addition to fueling, the Pro-M EFI system also utilizes closed loop feedback to precisely control idle speed.  No more surging or varying idle speeds as various loads are put on the engine.  The PCM constantly monitors actual idle speed, compares it to the target idle speed, then uses both the idle air control valve and spark advance until actual and target match under any condition. Furthermore, the PCM uses adaptive controls to “learn” how to control the idle speed and stores this information in its memory.

We even apply closed loop strategy to our water/methanol injection controls, which means you get exactly the amount of water/methanol injected into your engine that you asked for. OEM level control of an aftermarket add-on.  It just doesn’t get better.

3) The Pro-M EFI system will run nearly any engine at an OEM level right out of the box. No tuning needed. But if you want to make changes, there is nothing simpler.

Again, herein lies the beauty of mass air.  We always know exactly where we need to be in the base fuel and base spark tables because we are constantly monitoring actual ingested air mass and using this to calculate Load. Controlling both fuel and spark is as simple as delivering the commanded amount from the cells in the tables that correspond to the Load and RPM at that given instant.  There are also modifiers for things like air charge temperature and coolant temperature that will adjust the target fuel and spark as required, but we have those all covered as well.

We ship every Pro-M system with all the fuel, spark, and modifier tables written for you. The values provided in those tables will give you the optimum blend of power, drivability, and fuel economy. A proper tune is a blend of all three of these things. We obviously aren’t going to give you values that will run your engine on the ragged edge to squeeze out every last drop of power. But if you'd like to modify those tables to make more, you certainly can.  Add or subtract whatever you want from the base fuel and base spark tables.  That’s all there is to it.  The Pro-M EFI PCM will use the new values. Simple as that... 

Many people who are shopping for engine management systems are doing so because they've spent a lot of money on performance parts hoping to make big power. Now they need something to pull it all together and make it run smoothly and reliably. Roll into a car show or even a gas station in a modified vehicle and what is the number one question you hear?  It’s not “How smooth is your idle?” or “How does it run at part throttle?”  It’s “How much power does it make?”

If you want the answer to that question, we know you’ll be taking your vehicle to a dyno.  You can leave the calibration (or “tune”) alone and get your numbers.  But, if you’re really in the game of making maximum power, we provide an easy way to modify the fueling and spark advance yourself to see if there is room for improvement.  Or if you prefer, you can have a professional tuner do it for you.  Tuners who have used our system agree – it’s as simple as simple can be to use. 

Either way, you're not going to need to worry one bit about getting the engine to run right (provided it doesn’t have any mechanical issues).  That includes cold starts, idling, cruising, deceleration… everything.  No tuning needed.  As for power, some quick changes for fuel and/or spark can be made in a matter of minutes to see what (if anything) can be gained.  You’ll be in and out of the dyno in record time saving you time, money, and headache!

4) Pro-M’s system includes OEM style controls for all the popular “add-on” performance enhancing features.

As mentioned earlier, we can control water/methanol and nitrous oxide. We can control your automatic transmission. We offer helpful features like launch assist and traction control. We even offer an OEM quality Flex-Fuel system.

Why does that matter?  Many of those items are available in separate packages in the aftermarket.  Let’s use water/methanol (WM) as an example.  You can buy a WM system that comes with its own controller. The problem is that the system controlling the engine and the separate controller for the WM system aren’t communicating with one another.  With a separate controller, the engine management system has no idea that the extra fuel (methanol) is entering the engine.  The result is the engine starts running rich from the extra fuel.  There are tuning tricks to work around this, but that’s what they are... Tricks.  Also consider the time and money you’ll spend trying to get it to run properly.  The OEM doesn't use tricks to control your multi-thousand dollar engine. Neither do we.  Because our system is controlling the WM system and commanding an exact flow amount, and because we monitor the actual flow being delivered, we know precisely how much fuel to deliver via the fuel injectors. This maintains the proper a/f ratio at all times. No tricks... We also know precisely how much to advance the spark based on our WM flow / Spark Adder table.  On top of that, we use closed loop feedback to ensure that the amount of WM being injected is exactly what is being commanded.  That’s OEM level control of an aftermarket product.  The same fully-integrated control concept is applied to all the other features as well. No one else does this…

5) Pro-M uses and endorses only the very best components for its engine management systems.

 Inferior quality parts can be your worst nightmare. It doesn't matter how fast the car is if you can't keep it out of the garage.  For that reason, we use only the finest parts available.

The Pro-M EFI PCM is essentially a production Ford module.  It is made on the same assembly line as the Ford ones are. It goes through all the same rigorous testing as the Ford modules. You'd be surprised what they put these through… Our modules share no code whatsoever with the production Ford modules, but our code is written by Ford contractors. You simply cannot do better than that. Why do we do this? We assure you, it's not because they are inexpensive. They are anything but. We do it because they are the best. Period...

The Mass Airflow Sensors…  We truly believe our MAFs are second to none.  We have been providing MAF sensors and generating MAF transfer functions virtually since the advent of the technology.  No one knows it better.  We perform all of our own flow testing and generate all our transfer functions in house right here in the USA.  We have a variety of mass airflow meters employing many sizes, shapes and designs. We know what works best in a particular application. We are after all, primarily a mass air meter manufacturer.

Our wiring harnesses are constructed right here in the USA with the finest quality components available. Our exact fit powertrain harnesses are made to be exact duplicates of the originals, using all of the same connectors as the original harnesses for a fast and simple installation. These harnesses are assembled then covered in a protective loom, then wrapped in friction tape for good looks and to protect them from damage. Our universal fit harnesses are preassembled, but configurable for use in most any vehicle. These harnesses include protective loom and harness wrap so you can cover them up and protect them after you've configured them as needed. You will not find a better harness.

Some Frequently Asked Questions:

  • Can I install your system myself?
    • That’s really going to depend on your abilities. If you’re capable of removing your factory harness and remembering where everything goes when you plug in our new one, that’s a big plus.  Outside of that, you’ll need some basic computer skills to download a program from our website and work with email attachments.  Probably most importantly, you need to be capable of following directions and working methodically.  If you’re not intimidated by any of that, then you should be totally qualified to get a Pro-M system installed and running in your car on your own.  If you prefer to have the work done for you, then anyone meeting the requirements above can perform the work. It does not need to be a shop. 

  • But isn’t a Mass Airflow Meter a restriction?
    • This question originated back in the days when the Fox Body Mustangs came equipped from the factory with a very small Mass Air Meter that couldn't support much more than the stock engine. Is a mass airflow meter a restriction? It can be… Much like your intake manifold, or your throttle body, or your air cleaner can be a restriction if you choose the wrong one.  For nearly 30 years now, Pro-M Racing has been selling Mass Air Meters that can support as much as 2000 horsepower. If that is not enough, then we can use two of them!

  • My car has some mechanical problems. Is that going to be an issue?
    • Most likely, yes. An engine management system isn’t a bandage for problems in the engine or fuel system.  Don’t expect it to be.  Proper drivability is dependent on the components in your car operating as they should.  That said, the OEM level OBD II diagnostics of the Pro-M EFI system will help you to iron those out.

  • You make your system sound like the greatest thing out there. Is it too good to be true?
    • We honestly believe that no other system currently available will be able to deliver the OEM level of drivability and quality that we offer.  But… that doesn’t mean that we can’t do better.  The truth is technology is advancing all the time.  Pro-M constantly strives to take advantage of new technology and develop new components and software that will make what we think is already the best even better.  We release updates and add new features on a constant basis, often at no extra charge to pre-existing customers.  Do you have a feature in your car that we currently don’t control but would like us to incorporate?  Let us know!
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