Pro-M Racing

Hello everyone.

Pro-M Racing has been in the engine management business for many years. If you have not heard of us, it may be because we are best known for our products for Ford vehicles. Although we've been producing management systems for all makes for almost as long as we've been producing our Ford systems, the Ford stuff is certainly what we are famous for.

About two years ago, we released the new Pro-M EFI engine management system. Our new system is not only ready to run right out of the box (no tuning needed), but also includes what we believe is the most powerful tuning software available. Though you will find that the calibration file we provide with the Pro-M EFI system will run your engine perfectly right out of the box, the tuning software will allow you to make anything from minor adjustments, to major upgrades, such as forced induction, progressive nitrous controls, and the most comprehensive water/methanol injection controls on the market, without buying additional controllers. It's all incorporated into our ECU, and it's all included in one package. Perhaps best of all, you will not need assistance from a professional tuner. Anyone who can follow basic instructions is fully capable of doing this on their own! A dyno would only be needed if you wanted to know how much power you're making. It is completely unnecessary for the purpose of simply getting a car up and running, and running at an OEM level at that. In fact, there really is no “tuning” needed at all with Pro-M EFI. It's really just data entry. Tell the ECU what it's running (Bore, Stroke, Injector Data, Nitrous, Methanol, etc.) and the Pro-M EFI system does the rest. There is no “Self Tuning”... Once you've entered the data, its done! Any adjustments you make from there are optional.

While we have had systems for older Chevrolet engines for some time now, the LS engine was an area where we'd been lacking. This has not been due to a lack of interest, but rather a lack of time. My personal time to be exact. I've had an LS engine here in my personal shop for years, and a vehicle to put it in as well, but other projects always seemed to get in the way. And, since we won't sell a product until I have used it personally, we simply have not been offering an LS system.

Well, early this winter, I decided it was time to make this a priority, and my LS engine now has a new home in my wife's Jeep Wrangler. The results are every bit as good as I knew they would be, but more importantly, we have now begun to offer the Pro-M EFI system for LS engines to the public.

Now we need to get the word out, and the best way to accomplish this is to get someone on the forum to try one, and report their experience for all to read. We believe we have the most user friendly, and the most complete system money can buy, and we believe that the results are far superior to the competition's. We are also well aware that no one is going to take our word for it!

What we are offering is a substantial discount to the first customer on this forum to try one. However, it can't be just anyone. This person needs to own a worthy vehicle, and needs to be someone who can dedicate the time to complete the project in a timely manner, and dedicate the time to report their experience to the forum members. It would also be best if this person had some immediate plans to do some substantial upgrades, such as forced induction, nitrous, etc., since we want to demonstrate how easily these things are accomplished with our system, and without the help of a professional tuner. In fact, if you are a professional tuner, we'd ask that you not participate in this offer for obvious reasons, although we would be happy to assist you with any future projects.

For more detailed information on the Pro-M EFI engine management system, or any of our other products, please visit our website at www.promracing.com. There you will find a full description of the product, and all of its features, as well as several articles that have been written about our new system, and instructional videos that can help you complete your project correctly the first time.

We would also welcome you to read about the experiences of our current Ford customers on www.corral.net in the forum section. You'll find several threads in both the “Engine management” section and in the “Supercharged” section.

I'd ask that anyone interested in this offer please send us an email message at info@promracing.com, and give us a brief description of your vehicle, your engine, and your future plans for upgrades. After we've considered all the candidates, I will call the most eligible candidates personally, and then we will make our final decision.

I look forward to speaking with those people, and to helping the forum members with their future projects.

Thank you,

Chris Richards
President
Pro-M Racing, LLC
336-644-8668

stevieturbo

You may get a better response from the forced induction sections. As these are the guys more inclined to use aftermarket systems, and need more tuning features.

Pro-M Racing

Will do... Thanks for the tip. Hopefully no one minds the double post.

roninsonic

iTrader: (3)

I have a fairly wild street 370 that I'm dropping in this weekend, big cam, high stall converter, ect. should be ready to fire up in a week or two. Do you have any more details on the setup? Does it utilize aftermarket harness or factoryone? Control transmission?

I haven't been to the site yet, going now.

I DO plan on a 200 hit of nitrous soon, but I'll need to do the rear end before that happens. let me know if this sounds like it might be a good build to showcase for you.

Pro-M Racing

We are trying to keep all the entries in one place, so if you are interested, I'd ask that you please send an email to the address in the post above.

The system comes with a complete assembled stand alone harness. Transmission controls have always been in the plans, and just came to the top of the priority list, so they will be next. Systems that were sold prior to the release of the transmission controls will only require a re-flash for their computer, which can be done at home. No need to send the ECU in for the updated strategy. In the past, as we have released new features, those upgraded strategies have been free, and that is the plan for the transmission controls as well. The only thing that will need to be purchased is the harness that goes to the transmission. That harness will be separate from the engine harness.

Project GatTagO

iTrader: (7)

For $4K it had better do something spectacular...

Andrew

Pro-M Racing

That price includes an intake manifold, fuel rails, fuel injectors, throttle body, all the sensors (including a choice of a variety of Mass Air Sensor designs), a complete assembled wire harness...

It's not just an ECU.

Project GatTagO

iTrader: (7)

Is there a link to an ECU and harness package?
Will this work with factory sensors?
Will it work with DBW?
Does it have any programmable inputs and outputs?

Andrew

SSZ

Am i mistaken??? Is this for 56x engines only or is there an option for the 24x?

Pro-M Racing

I should clarify that this system is not really intended for vehicles that came from the factory with an LS engine. It is really aimed at someone who is doing a transplant. The intention being to make life easier than it would be if you were going to use the harness and ECU from a salvage vehicle, and to spare the installer the hassles of building a new harness and tuning the typical aftermarket ECU, while still offering the ability and flexibility to use forced induction, nitrous, meth, etc. with ease.

"Is there a link to an ECU and harness package?" -- No. Complete package only.

"Will this work with factory sensors?" -- You would use a blend of our sensors, and the factory sensors. Our TPS, IAT, Wide band O2's, Mass Air Meter. The GM ECT, crankshaft and camshaft position sensors.

"Will it work with DBW?" No... DBW really doesn't make a lot of sense in a transplant. The main idea behind DBW being to position the throttle somewhere that results in maximum torque in a given situation. Since this is heavily reliant on the combination of engine parts, transmission, gear ratios, and vehicle weight, and since that combination is now gone in the transplant, it now makes more sense to just use a cable.

"Does it have any programmable inputs and outputs?" -- It does, but we really take a different approach than most here. Rather than just providing you with an output, and telling you to set it up however you choose, we've done it for you. An example would be electric cooling fan control. We could have just allowed you to activate an output based on coolant temperature, but to do this at an OEM level, there needs to be more too it. That electric cooling fan will create a draw on the charging system. That draw makes the alternator harder to turn, and therefor becomes a load on the engine. So we have parameters to bump up the IAC to compensate for that drag. There is more to it than that, like how it integrates with A/C compressor control. So the idea is to do more for the customer than to simply say "Here's an output... Good luck making it work properly." That said, there are a couple of user programmable outputs that will cover you if we've forgotten something...

Pro-M Racing

"Am i mistaken??? Is this for 56x engines only or is there an option for the 24x?" --

58X only at this time.

Pro-M Racing

Here is some more info on our product...

First, our website is an absolute wealth of information, including how to videos, and a complete description of what you get and what it does. To try to cram all of that into a forum post would be difficult at best, but it's just a click away. That said, if you have a question, I will be happy to answer it, whether it was covered on our website or not.

A little more clarification on our reasons for not offering DBW -- If your going to put an LS engine in an older car, it's much easier to connect your existing throttle cable than it is to change to DBW. Offering DBW with programmable tip in and ramp up only serves to make the customer spend more money, do more work, complicate the system, and for no good reason. The end result is the same. You push the pedal and the throttle moves. The main reasons DBW was introduced by the OEM simply do not apply to a transplant. It is entirely unrealistic to think that the do-it-yourselfer will get any benefit from an aftermarket version of DBW. The OEM puts a tremendous amount of time into the logic for each particular engine, transmission, gearing, and vehicle combination. They can amortize this time over hundreds of thousands of vehicles, which makes this effort worthwhile. To think that this could duplicated for one vehicle is simply unrealistic. The existing throttle cable simply makes more sense.

The intake manifold, fuel rails and throttle body are included to simplify things for someone who wants a complete package. If you've purchased a long block, you'll need an intake, etc. If you've purchased a salvage engine, as I did, maybe you don't like the look of the intake, or maybe that intake and throttle body do not package will under the hood of your vehicle. If you don't want them, we will absolutely have a conversation with you about what you already have, or would rather buy, help you configure our kit to make that happen, and reduce the price. That said, I think you'll find that we have a pretty cool package. The intake and throttle body give an old school look to the engine swap. We even have a mass air meter that will hide inside of a traditional 4 barrel air cleaner. The end result looks very much like it has a carburetor. This has proven to be very popular with customers putting EFI in their older cars. We've sold thousands of these. Picture below...

Pro-M Racing

Some information about the Pro-M EFI system and how we are different from other aftermarket systems.

One difference between our system and the others is how we go about calculating the needed air/fuel ratio, and the correct spark advance.

Any good engine management system will base all of its fuel and spark calculations off of a value called “Load”. Load is everything in engine management. Quite simply, if you have an accurate “Load” value, you can very easily command a proper air/fuel ratio and a proper spark advance. Load is Load, regardless of the engine or the combination of parts. And any given Load will have an optimal air fuel ratio, and an optimal spark advance. Keep that basic principle in mind as you read through this.

The simple definition of load is... The mass of the air being ingested by the engine, divided by the engine's potential for air mass. There is actually a little more to it than that, but this definition will suffice for this discussion. So, its similar to volumetric efficiency, but rather than looking at the volume of air, we are looking at the actual mass of the air.

I should point out that all good engine management systems use Mass Air to determine a value for Load. Yes, even the Speed Density systems use Mass Air... The difference between these systems is how they go about getting the air mass value. This is why the classic debate over which system is better (Mass Air vs. Speed Density) is completely ridiculous. You are all using Mass Air calculations guys... it's really just a matter of what method you are using to come up with the air mass value, and whether or not that value is accurate.

So here's how it works...

Ingested Air Mass (Whatever amount the engine is actually using at any given time) / Potential Air Mass (The air mass that would fill all of the cylinders) = Load.

Load and RPM are then applied to the base fuel table and the base spark table to come up with values for the amount of fuel and the amount of spark advance. Pretty simple really. Not every system uses this exact method (although they should). Some use simpler and less effective strategies.

Again, one main difference between one system and another is how they come up with the Air Mass value. Mass Air systems simply take that reading from the Mass Air Meter, and apply that value to the equation above. Speed Density systems have to calculate the Air Mass value.

To do this, Speed Density systems use a Volumetric Efficiency table. The VE table is generated by taking an educated guess at the values for VE for any given RPM vs Manifold Pressure. The idea being to come up with a table that accurately represents VE for a particular combination of engine parts at standard temperature and standard atmospheric pressure. Then those values are applied to mathematical equations to convert that standard VE value to a corrected VE value for the current temperature and atmospheric pressure. Then that value is applied to another mathematical equation to come up with a value for Air Mass. Then the Air Mass value is applied to the equation that comes up with a value for Load. Then the Load value is used to come up with your air/fuel ratio and spark advance. Again, not all Speed Density systems use this exact method. They should, but that is not always the case. I should also mention that the OEM abandoned using VE some time ago, even when not using a Mass Air management system. More on this later...

Do both systems work? Yes they do... The challenge of a Speed Density system is to properly calculate the Air Mass value, which is of course is different for every combination of engine parts. The beauty of a Mass Air system is that it makes absolutely no difference what the combination of engine parts is.

Another cool thing about basing everything on Load, is that it makes absolutely no difference whether its naturally aspirated, or has forced induction. The combination (whatever it is) will simply equate to some value for the Air Mass being ingested by the engine, and that value will be used to calculate Load, which in turn will be used to come up with the commanded air/fuel ratio and the commanded spark advance. Load values over “1” are the result of forced induction. As the values go higher, the mixture should be richer, so you simply command an appropriate air/fuel ratio for that Load value... Again, very simple. It gets better... The same is true for spark advance. The advance will of course increase as the load values approach “1”, but as the values exceed “1”, you will simply start to decrease the advance. The idea being to simply command a value for the advance that is appropriate for the Load value. This is a much better method than to command some amount of advance, and then start removing some amount of advance based on “Boost”. Why not just command an appropriate advance in the first place? The fact is... Basing any part of your calibration on the level of “Boost” being made is a terrible method. I'll cover that topic later.

So... regardless of how you come up with your Air Mass value, whether using a Mass Air Meter or Speed Density calculations, if the Air Mass value is accurate, you can use Load as the basis for the entire calibration. Using Load makes your life very easy. Everyone should do it. Not everyone does.

So why use a Mass Air meter? I think a better question is... Why wouldn't you?

There is an analogy I like to use when people ask me that question. As ridiculous as what I am about to write may sound, it illustrates my point perfectly...

Lets say you are sitting in your living room, and you are wondering what the temperature is outside. There are a couple of ways you could find the answer...

(1) We could attempt to do this mathematically using equations that will allow you to calculated the outside temperature based on the inside temperature... You could get a thermometer, and measure the temperature inside your living room. Then figure out how much heat your heating system puts out. Then you could correct for how much heat your body is making. Hold on... the wife just walked in and turned on the TV. That is two more heat sources. We will also need to know how well your house is insulated. Now lets apply all of this to complex mathematical equations, and come up with our outside temperature. Once we have done all that, we can carry the thermometer outside, and see how well we did. There will almost certainly be an error in the calculation, so lets just take another guess at the “R” value of our insulation, and see how we did this time. Wrong again? Well, take another guess, over and over until we get it right.

(2) You could have taken the thermometer outside in the first place, and been all done.

In example one, guessing at the “R” value of your insulation is much like tuning your VE table. Example two is much like using a Mass Air Meter. Do both methods work? Yes they do, and there are a lot of people who prefer the challenge of method one. I mean absolutely no disrespect to those people. There is something to be said for someone who enjoys a challenge, and if that is the kind of challenge you are looking for, then Pro-M EFI is not for you, and I am not here to change your mind.

Personally, I'll take option two... Engine management is what I do. I've been doing it at a professional level for nearly 25 years. I enjoy it very much. And that said... I still have no desire to do it every time I change something with my engine.

“But a Mass Air meter is a restriction” This ridiculous statement has been used by the speed density advocates for years. Can it be a restriction? Of course it can, if you use one that is too small. Just like an air cleaner, or a throttle body, or even an intake manifold, it should be sized properly. Would you buy a throttle body that is not big enough for your engine? Of course not... We have Mass Air meters that are absolutely enormous if need be.

“The Mass Air meter does not have enough range to support my horsepower” This is why we offer Mass Air meters with a variety of calibrations. It's not an issue.

“Ive had an awful lot of trouble and spent a ton of money tuning my GM Mass Air system” Yes... I know... Our works differently. The Pro-M EFI system does not have the limitations your GM system has. Once you've installed a Pro-M EFI management system, you won't no whether to smile because it was so easy to use, or cry because you spent so much time beating your head against the wall using someone else's stuff.

Pro-M Racing

And now a statement that will surely anger the Speed Density crowd. No need to be angry. The following is not a criticism. Its just a fact, and one that helps to illustrate the difference in our methods.

VE, while a very meaningful term when it comes do engine design, is a meaningless value in engine management. Again, the purpose of this post is not to anger anyone, or convince you to come over to the Mass Air side. I have found over the years that someone who is a die hard speed density advocate will fight to the death to defend it. I stopped trying to convince those people a long time ago. Again, all of this is just to demonstrate how we are different. I have nothing but respect for those who are willing to put in all the effort needed to make a Speed Density system work properly. No one needs to get angry.

You're not going to measure VE. You'll simply guess at it until you get the result you want. The VE table could just as well be named “The Guessing Table”. And since the value you end up using to get the result you want is probably not an accurate representation of the engine's actual VE, that value is truly meaningless. For this reason, the OEMs are moving away from using VE. And no, I am not referring to years ago when most OEMs switched to Mass Air. Not every production car uses Mass Air. However, the ones that don't are now moving towards a method of calculating the Air Mass value by using a relationship between Air Mass, throttle position and manifold absolute pressure. They are not using VE in any way, shape, or form. They are measuring Air Mass with a mass air meter, and comparing that value to a combination of throttle position and manifold absolute pressure. Once they have it mapped out, the mass air meter comes off, the calibration file is written, and then used in production.

How does this help you? Well, other than educating you on something you may not have known about, it doesn't... This method is not practical in the aftermarket. At least not yet. We have plans to develop a system to make this method practical for the aftermarket in the future. But for now, if you're going to use an aftermarket Speed Density system, you'll be using VE. I bring this up simply to illustrate a point. The remaining portion of the OEM that is not using Mass Air management is moving away from VE. Your aftermarket Speed Density system still uses VE. Take from that what you will...

Here's another one... Again, no need to get upset...

Tuning using boost pressure is a terrible method.

Boost is simply a measurement of the pressure being created between the supercharger (or turbo charger) and the engine. It does not represent air flow. It does not represent cylinder pressure, or temperature, or anything else meaningful for that matter. Much like VE, “boost” is a meaningless value in engine management.

Lets say you were to put a supercharger on a stock engine. Lets say that this combination produces 15 lbs of boost. Tuning using boost, you would command an air/fuel ratio and spark advance that you feel is appropriate for 15 lbs. Now lets put a better set of heads and a cam on that same engine. No other changes. Now the engine is more volumetrically efficient (again, a term that actually means something when discussing the engine itself), and creates less restriction, and that same supercharger may now only create 10 lbs of boost against the less restrictive engine. Using the “tune based on boost” method, you could now pull some fuel and add some advance. We're only making 10 lbs! The problem is, the engine is now actually moving more air than it did before, despite the lower boost level. So does this method make sense? Nope....

What does make sense? Load makes sense. Load is everything in engine management. And the only way to come up with a value for Load, is to have an accurate value for Air Mass. And the best way to come up with an accurate value for Air Mass, is a good Mass Air meter.

Here's another way we are different... Does this statement (or some version of it) sound familiar?

“You'll have total control and unlimited adjustably. Tune the system to your engine's exact blah blah blah”

Sounds great, but here's another way to say the same thing...

“We gave you a calibration file that will not run your engine”

Again, I have nothing but respect for you if you decide to take on such a project. That said...

When you buy a Pro-M EFI system, you're going to get a proper calibration file. It's done. Seriously, just turn the key. If you want to play with the calibration, go right ahead. But this is absolutely unnecessary. The engine will run at an OEM level just the way it is.

It is not “Self Tuning”. It does not need to self tune. It's already tuned. There is no trick to this. We simply give the ECU all of the tools, and all of the information it needs to do the job correctly right out of the box. This is the beauty of a system that uses Mass Air, Lambda and Load. There is no Voodoo to engine management. At least there doesn't have to be. Give the ECU what it needs and you will have good results.

And on the subject of “Self Tuning” Does this scare you? It should... Self tuning is really nothing more than “short term fuel trim” on steroids. I think we would all agree that using wide band O2 sensors is the only way to go. But to give them total control over your fuel table is just asking for trouble.

A wide band O2 sensor should be used to make small corrections to a calibration file that is already correct. A calibration file that would work well with no O2 sensors at all.

Wide band O2 sensors should be used to alert the driver that the fuel trims have reached some unacceptable limit and that something is wrong and needs to be fixed.

Wide band O2 sensors should not be allowed to react to whatever that problem may be, with no limitation to how far it can adjust your fueling, and “Self Tuning” is just exactly that.

If the calibration we provide with your Pro-M EFI system does not work right out of the box, then something is wrong with your car (not the calibration), and our system will absolutely not self tune in an attempt to correct that problem. Instead, we will help you to find the problem with your car, and correct it. Our tech support is second to none.

One more thing I'd like to mention is our progressive water/methanol injection controls. There is an awful lot involved in doing this the right way, and we are the only product on the market that is doing this correctly.

The Pro-M EFI processor will progressively ramp up the delivery of water/methanol to the engine, while progressively adding spark advance in proportion to the amount of water/methanol being injected. It will also compensate for the amount of methanol being injected by adjusting the flow of fuel through the fuel injectors. The system also incorporates several fail safe features that will shut down the water/methanol system, and most importantly, stop adding the spark advance, should the water/methanol system fail to deliver the desired amount of water/methanol.

The desired amount of water/methanol being sprayed is determined by a user adjustable table based on Load and RPM. We use a flow sensor to verify the actual amount of water/methanol being injected. We control the water/methanol pump using duty cycle. The duty cycle is adjusted using closed loop feedback from the flow sensor. You will always get exactly what you've asked for.

The stoiciometric AFR of the methanol, and the amount of methanol being injected is then used to calculate the amount of air that will be burned along with the methanol. This amount is then subtracted from the total air flow being measured by the Mass Air sensor. The remaining air mass will have fuel added to it via the fuel injectors. So the correction factors are tight even when spraying meth. This method is only practical with a Mass Air meter. Then the whole thing is wrapped up in closed loop fuel control via the two wide band O2 sensors.

The spark advance is increased based entirely on the amount of methanol being sprayed. This is the reverse of the way it is typically done. Normally, the spark advance table is written based on the use of the methanol. Then there is hopefully some way to decrease the advance as a fail safe should the meth system fail. With our system, the spark advance table is written assuming there is no methanol. Then advance is added if methanol is being sprayed. The amount of advance added is based on a user adjustable spark adder table (amount of methanol being injected vs added advance). The beauty of this is that no spark advance is added unless a flow of methanol is detected by the flow sensor. You cannot pop an engine if the meth system fails, since the spark advance was never added. And since the spark adder is based on the amount of meth being sprayed, you cannot add too much advance when there is a partial failure, such as the water/meth tank getting low and intermittently sucking air.

We have progressive Nitrous controls too. They work using mostly the same principles described above. If you've ever tried Nitrous and didn't like it, I'd encourage you to try it again with our system. You'll love it.

One of our test cars has a supercharger, progressive nitrous, and progressive water/methanol all working in perfect harmony all at the same time with OEM level drivability. That is just not going to happen with any other management system.

And the whole thing is monitored using OBD II diagnostics. We use the same OBD II code structure used by the OEM. Same codes. Same definitions. Those codes can be read and cleared using either your laptop, or any generic OBD II scan tool.

In short, if you want a management system that works at an OEM level, has the flexibility you can only find in the aftermarket, and is easy enough to eliminate the need for a professional tuner, give us a call.

mrvedit

Very informative to read a slightly different approach to tuning. You are obviously very knowledgeable about the subject.

A couple questions come to mind:

Q1 - GM uses the VE table for sanity checks of the MAF. A failed MAF will barely affect operation of a stock setup. How does your system make up for the missing(?) VE table if your MAF fails?

Q2 - You kinda claim that the physics of internal combustion provide formulas which are implemented in the PCM and therefore require no tuning. However no formula can account for the non-linear characteristics of a camshaft, especially not a high overlap cam. Such cams require major re-tuning. Either your system self-tunes, uses custom tunes or relies extensively from wideband O2 feedback. Please clarify.

Q3. It is particularly difficult to tune the idle for high overlap cams. How is this handled?

Pro-M Racing

Q1 - GM uses the VE table for sanity checks of the MAF. A failed MAF will barely affect operation of a stock setup. How does your system make up for the missing(?) VE table if your MAF fails? --

Excellent question... The GM strategy is fantastic on a stock engine. No so much when you make modifications. We have some options here...

(1) You can choose to do it the way GM does it. We do offer speed density and a VE table if you choose to use them. You could edit the VE table to your needs, and then choose speed density as your secondary strategy if the meter fails. You can even choose speed throttle as a third fall back if you want. I would suggest that you not go through the trouble. Mass Air meter failure is very rare, and you will spend a lot of time refining your VE table, and likely never use it. And if you do choose to go through the trouble, I'd suggest you spend very little time on it. Make it run good enough to get you home and that's it. Again, it is very unlikely that you will ever need it.

(2) You can choose to do it the way Ford does it. There is a default value for the MAF if the meter fails. It will run good enough to get you home. This is the way we set it up, and you would simply change it to option 1 if you desired.

While we are on the subject... What makes the GM strategy so good on a stock engine is what also makes it a pain when you've made modifications. Someone tuning a GM system on a modified engine will find three things:

(1) There are limited options for a larger MAF with a suitable calibration for use with GM management and a high performance engine. The aftermarket manufactures do not bother making them because...

(2) If you find a MAF that suits your airflow and calibration needs, you will now find that the GM strategy does not allow you to make entries in the MAF table over a certain value. Then the "scaling" game begins. Then...

(3) You'll find that you have to tune the speed density side of the strategy as well. Given that you have to go through speed density hell anyway, at this point, most tuners will simply just switch to speed density and get rid of the MAF. This is where MAF based systems get their bad reputation in the GM world, and with good reason. Understand though that it doesn't have to be this way. We have non of these limitations with Pro-M EFI.

Q2 - You kinda claim that the physics of internal combustion provide formulas which are implemented in the PCM and therefore require no tuning. However no formula can account for the non-linear characteristics of a camshaft, especially not a high overlap cam. Such cams require major re-tuning. Either your system self-tunes, uses custom tunes or relies extensively from wideband O2 feedback. Please clarify. --

You're over-complicating it. The new cam results in a new airflow, which results in a new Load value, which results in new air/fuel ratio. We've proven this time and time again. You can quite literally swap around heads and camshafts all you want with not a single adjustment to the tune. If the new combination of engine parts is so drastic that it requires a different supporting component, such as different injectors, then you need to enter the new fuel injector data, but that is all.

Q3. It is particularly difficult to tune the idle for high overlap cams. How is this handled? --
Not difficult at all. Again, our Mass Air system doesn't use manifold vacuum as part of the strategy. We do not care in any way what the cam grind is. It simply does not matter. The resulting airflow is measured, and used to calculate the Load. That's it... In worst case scenarios, the wide band O2s are ignored below a certain RPM. An O2 sensor is easily fooled by a cam with a ton of overlap below a certain RPM. If that is the case, simply choose a "Minimum RPM for Closed Loop Control" and it will run in open loop below that RPM. Very simple.

joecar

I don't see mention of wideband... does this system use wideband O2 sensors to do closed loop trimming (thruout the load/fuel/rpm range)...?

Pro-M Racing

It uses a pair of wide band O2 sensors, and is in closed loop at all times, unless you tell it to do otherwise.

Pro-M Racing

Here's a link to a page on our website with a bunch of magazine articles that have been written about the Pro-M EFI system, and an episode of Performance TV we did recently.

http://www.promracing.com/media/

And here are some links to some success stories on another forum.

http://forums.corral.net/forums/engi...nt-system.html

Very long, but informative -- http://forums.corral.net/forums/engi...ly-driver.html

http://forums.corral.net/forums/engi...nt-system.html

http://forums.corral.net/forums/engi...ce-review.html

http://forums.corral.net/forums/supe...fi-system.html

One more... Painfully long (462 posts at the time this was written), and there is no shortage of drama, but there is a ton of information here. -- http://forums.corral.net/forums/supe...nt-system.html