OEMs all the way...never had a pro-m...told by too many tuners not to bother with one.

the pro-m has 9 sample points versus an OEM 30

that's some crappy resolution right there. And with a small car like the focus, the range of larger OEM ford MAFs is huge.

these aren't lightnings already running 100mm MAFs here

 

1. What led you to make said purchase?

2. What brand and size?

3. What mods do you have?

4. How did it work?

5. What the MAF worth the money?

6. Would you do it again? Please explain in detail.

So let's hear it, consumers and vendors, everyone.

at first, I bought a Cobra MAF... there was talk you could get a 70mm Cobra MAF, I bought into it, and bought a 2002 cobra MAF == 90mm Lightning MAF. It was HUGE!.. the boys at the shop were able to fab it to fit, minus the flexhose, and with the filter hanging precariously lower in the car.

I installed it into my vortech supercharged focus, inputed the values in the SCT package, and started the car. It would not idle at all below 1000RPM.. below 1000 RPM, the car would pulse, flying up to 1200RPM, and down to 750 to attempt idle, but then nearly stall, and pulse back up.

Rinse and repeat. weather there was turbulence from the Bypass valve, or the fact that a focus doesn't pull enough air above the minimum A/D count (adjustable) to get a steady reading of air at idle, and making things very difficult. You could work around this, but considering the lack of resolution of a MAF rated for 60lbs/min of air on a car running 30 lbs-min of air... well, it was silly (in retrospect). So the stock MAF went in, the stock MAF value file went into the SCT software and flashed.

The car started, ran beautifully up to the MAF's supported 160HP (5200RPM redline)..enough to drive the car until a new MAF can be found.

So I ordered a 65mm pro-M... .it would slap onto the supercharger inlet's flex hose like the stock one, bolt nearly directly on (but at 1" longer, makes the fit a little tight), and the vortech airfilter was waaaay larger than the inlet diameter... nothing a few laps of electrical tape couldn't fix tho. Oh, and the sample tube and electronics made nowhere near a tight seal with the main tube, which I figure equates to the crazy error deviations they log on the flow sheet.

So I sealed it up with some liquid gasket, and was able to make a tune with the 9 point graph, using the actual measurements, and not the error-corrected ones, and on the 1st start, my air/fuel was nearly dead on.

Until yesterday.... in 30C heat, the car ran dandy coming out of my cool underground garage, but as I climbed some of the hills, and the car warmed up (sun beating down on my twilight blue car), the car got to a point where it had trouble idling, stuttered on throttle tip-in, and then she wouldn't idle. Stall.. start up, it would run a few seconds, but as the RPM dropped to it's stock idle point, it bogged, and stalled..pressing on the gas would keep it alive a bit longer, but it would eventually choke.. ok time to tow it back home.

Back home, and after the tow truck left, it was cool enough to start the car, and get it into the underground garage. The way I see it, my tune was alright, but I botched the low end below the idle point at 20C... from the fuel smell, I would say that I set the airflow too high for the given low-end A/D counts, and the car thought it was getting more air than it was.. flooding the engine.

I now have a wideband O2 sensor on order to help fix these niggling problems, because there is a good possibility I'll need it come winter to tune the upper ranges.

the lessons I've learned boil down to:
The Stock MAFs
1) Stock MAFs rule.. they have known flow rates, and tested value tables
2) If you buy a stock one, get the closest you can to your projected HP goals. Each MAF has at least a 10% margin over what the car it's built for is capable of (ie, a stock focus MAF is good to 160HP, and SVT good to about 210 HP). Go too large, and you risk losing much needed resolution
3) other stock MAFs will require fabrication to fit. But chose between tuning, or fabbing, fabbing is probably a slightly easier way to go

aftermaket MAFs
1) you can get them in the size and injector calibration you wish ... Pro Flow doesn't only make 70mm MAFs
2) you can avoid fabbing
3) it's possible to make a very near tune with their 9 values
4) but you will need to tune regardless, and you may miss points you'll need when the weather changes, so make sure you own some datalogging software and a wideband O2 and don't be surprised when it goes weird on you.
5) Aftermarket MAFs aren't all built equal.. do a quick once over to make sure.

If I wasn't tired of spending money on MAFs that don't work, I would go with the stock ford MAFs... fabbing sucks, but without the proper tools, tuning sucks worse, and takes longer... and for $250, the aftermarket MAFs are absolute letdowns in quality, looking like the recalibrated stock MAFs built from parts matching that they really are.

 

I have the Pro-M works good made power. Went from 154 to 159. Get some real background on this company. The factory units started here.
My 9 point mass air looks nice and even on the dyno with my SCT setup.

Blueoval what tuners and how many.

 

I have the Pro-M works good made power. Went from 154 to 159. Get some real background on this company. The factory units started here.
My 9 point mass air looks nice and even on the dyno with my SCT setup.

Blueoval what tuners and how many.

That's funny.. I guess I could see a pro-M making power on a stock focus with an aftermarket TB.. but on a stock TB, the stock MAF provides little, if any, extra restriction. I bet you could make the gains by tuning alone.

I don't care about the background of the company.. even if they invented MAFs, the ones I've seen in person (including the one I bought), don't look stock, and aren't nearly consistent build quality as stock.

Blueoval, you must be wrong, a tuner shop wouldn't turn you away from Pro-M.. they can't make money if they get the tune right on the 1st try!

To be honest, I'm very disillusioned with all the aftermarket parts out there, because to me, I'm not seeing much difference between them and APC garbage. Nothing fits right out of the box, it all requires tweaking, and people pay big money for it... and are happy to! I can hardly wait to go put this gauge pod on to find out how much modifying I'm going to need to make it fit properly.

In the end, I would highly recommend buying the OEM MAFs instead.. not to hurt Pro-M, but to save people a lot of grief and expense with tuning.

 

3 from the 3.8mustang world...I haven't been involved in that in a couple years, so i forgot the names, but it'd be a snap to get them, Randy from FocusSport, and a couple of local mustang guys.

I think the Pro-M could work, i just feel like with the 9 vs 30 difference and the difference in percentage of defects (it could be relatively low on the Pro-M, but i've never heard of a brand-new BAD OEM MAF)

 

I've been researching Mustang MAFs for when the SCT flasher comes out, and something people brought up was the OEM work best in a suck-through operation, and for a blow-through, you are better off with something like a Pro-M. Opinions?

 

I will agree that not all Foci need to go to a larger MAF , We have seen no gain from a MAF below 130,135 range but from there on we start seing small gains, Each customer needs to decide from there if the cost is worth the gain

I have used and tuned HUNDREDS of Pro-M mass air units and have had trouble with just a few , Altho i cannot say that they are all the same with proper tuning they can all be made to work properly

With FI at about 170HP depending on the unit you start getting into the mid to high 4 volt range and for safety we like to change the mass air at this point and in most cases you are out of injectors anyway. 90 % of FI customers never stop there so save the customer some money and go ahead and tune the car the first time with the larger mass air/injectors and Pro-M is my first choise

Now stock mass air they work great problem is they are way to big or way to small and the whole in them are blocked by bulky metering tubes or supports ,For 200HP or less there great if you can get them to work with out tape and glue hook them up and tune away they will work fine

The Pro-M unit comes with every turbo kit i sell and is the Mass Air that is on the largest majority of the Focus community and that is because it works ,Being able to tune it is the key and to us that is NOOOOOOOOOOO problem

Tom

 

the pro-m has 9 sample points versus an OEM 30

There seems to be some confusion on this point. It doesn't matter how many sample points are used when calibration is done on the MAF. That does NOT define the Transfer Function table in the PCM. The Transfer Function in the PCM ALWAYS contains 30 mapped points. These values in the PCM need to be matched to the output of the MAF (Aftermarket or OEM).

The Aftermarket MAF does this in the opposite direction. By "calibrating" it's output to the STOCK transfer function with a shift in values to compensate for different sized injectors. It is then CHECKED at 9 points. That doesn't alter the 30 points in the PCM. If you ordered an Aftermarket MAF calibrated to STOCK injectors it should closely match the OEM MAF output.

I hope this makes sense. If not, can try to explain it in more detail.

 

1. What led you to make said purchase?

At the time I got my SCT-PR package(Last fall), all I really new about tuning was that I needed larger injectors and a larger MAF. I searched around for information, trying to find an OEM MAF suitable. I was told to try a MAF from some(can't remember the year) T-Bird. Got it home, and it was a 4 wire instead of a 6 wire which meant I would have had to hack my harness completely. Plus it looked like it was going to be very difficult to mate up to my Aerocharger compressor inlet pipe. So with time running out (I wanted to get the car running before a track event that was only a few weeks away), I went ahead and ordered a Pro-M based on imput from Jerry at SCT. Still had to do some fab work to get it to fit, but as I said, I was running out of time to look for another meter.

2. What brand and size?

Pro-M, 70mm, calibrated to 36# injectors
Chose the 36# injector sizing to make sure that I would never out flow the meter even if I bumped up the boost and added an intercooler (with some cushion of course). Its still a bit too large for my current setup.

3. What mods do you have?

Aerocharger stage II non intercooled turbo, ORP, 2.5" Borla, External wastegate set @7.25psi, Volant, relocated IAT/ACT sensor...

4. How did it work?

That's a good question. I can only answer it with what I know. I dynoed the car and it made 171hp/176ft-lbs at the wheels with a WOT A/F curve that matches the demanded A/F pretty well. But I do not have any datalogging equipment and have not checked the fuel trims at idle, cruise, etc... The car idles pretty well but I did bump the idle speed up about 100rpm's or so because of the poly engine mount. I do still occasionally get some light throttle stumble(even with the EGR disabled), that I don't know where its coming from. Could be the MAF, could be my timing values, who knows...
Edit:I should mention one thing though. The car is still in one piece after almost 7 hours of track time. Whether it lasts another hour or not, we'll have to wait and see.

5. What the MAF worth the money?

It got me on track for seat time so yes!

6. Would you do it again? Please explain in detail.

If I had to do it over again, I would probably look into a Ford OEM meter. At that time, I couldn't really pinpoint the SVT MAF's upper range. And that would have been a more likely choice for my current setup.

For the record, after I went through and searched for info for my setup, I tried to start a list of OEM MAF's that would be appropriate. I started it first on MD and then posted it over here. Sorry, it didn't get very far.

 

yeah, I should maybe expound on my statement.

Regardless of the flow sheet, if you're using SCT, you could use a simple equation to change the engine displacement scalar to match the calibrated MAF.

But I won't do that ... there are lots of tools out there to get 30point transfer functions from the 9 provided by pro-m, but after trying a few of those tools, they are WAAAAY off what my actual transfer function is (the one I figured out on my own, and runs perfectly, except for the lower idle points).

Tuning for pro-m is where experience really helps.

 

yeah, I should maybe expound on my statement.

Regardless of the flow sheet, if you're using SCT, you could use a simple equation to change the engine displacement scalar to match the calibrated MAF.

But I won't do that ... there are lots of tools out there to get 30point transfer functions from the 9 provided by pro-m, but after trying a few of those tools, they are WAAAAY off what my actual transfer function is (the one I figured out on my own, and runs perfectly, except for the lower idle points).

Tuning for pro-m is where experience really helps.

I was going to comment on that as well. If you use a 9 point table from the Pro-M flow sheet to create a 30 point MAF transfer function, you're obviously going to have some error. How much error? I don't know. I imagine it would be different in every case.

Also, not to hijack this thread but while we're talking about MAF's and transfer functions... How much does the 'stuff' around the MAF affect the flow? In other words, I don't think you can simply stick a Mustang MAF on a turbo Focus and expect it to have the exact same flow characteristics as it did on the Mustang. When you go from a stock Mustang air box and whatever intake plumbing it has, to a cone filter and whatever turbo compressor inlet plumbing you have on the Focus, the flow through the MAF is going to be different. Don't the OEM's calibrate the MAF to more than just the MAF housing anyway? I'd imagine that to have the best calibration, they'd want to use the whole intake track.

 

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think. These are just reference points for graphing the mass airs calibration and Pro-M uses 30 but only prints 9 If you want 30 printed just ask . I dont realy see why with being able to comtrole the MTF this is even an issue

Tom

 

What and where the MAF is located changes how the MAF responds BIG TIME

I have seen cars change idle with the cars fan kicking on and the filter 12 inches away

I my self have rotated mass airs and had them go from a crappy idle to a perfect idle

Tom

 

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think. These are just reference points for graphing the mass airs calibration and Pro-M uses 30 but only prints 9 If you want 30 printed just ask . I dont realy see why with being able to comtrole the MTF this is even an issue

Tom

Could I be misunderstanding how the MAF Transfe Function works? I thought that the ECU looks at each row, I didn't know it does it's own calculations based on whatever few (or many)points there are in the MTF to pull air measurements for even voltages.

Guess I'm going to go download that EEC whitepaper now...

 

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think. These are just reference points for graphing the mass airs calibration and Pro-M uses 30 but only prints 9 If you want 30 printed just ask . I dont realy see why with being able to comtrole the MTF this is even an issue

Tom

Could I be misunderstanding how the MAF Transfe Function works? I thought that the ECU looks at each row, I didn't know it does it's own calculations based on whatever few (or many)points there are in the MTF to pull air measurements for even voltages.

Guess I'm going to go download that EEC whitepaper now...

If I understand this right, the MAF transfer function is called a function because it is exactly that. It is a mathematical function. The data you enter into the table is what allows the computer to calculate a function (which could be represented as a curve on a graph) that it could use to calculate an infinite number of points. If it only goes down to three places, then the function is finite. But if you understand how a function works I think you get the point.

 

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think. These are just reference points for graphing the mass airs calibration and Pro-M uses 30 but only prints 9 If you want 30 printed just ask . I dont realy see why with being able to comtrole the MTF this is even an issue

Tom

Could I be misunderstanding how the MAF Transfe Function works? I thought that the ECU looks at each row, I didn't know it does it's own calculations based on whatever few (or many)points there are in the MTF to pull air measurements for even voltages.

Guess I'm going to go download that EEC whitepaper now...

If I understand this right, the MAF transfer function is called a function because it is exactly that. It is a mathematical function. The data you enter into the table is what allows the computer to calculate a function (which could be represented as a curve on a graph) that it could use to calculate an infinite number of points. If it only goes down to three places, then the function is finite. But if you understand how a function works I think you get the point.

Has anyone to this point come out and actually said with absolute certainty that the EEC will generate the 6th order polynomial equation needed to calculate airflow regardless of how many points are actually in the MTF table?

If so, I may have missed it, but this is good news.. makes things a lot easier!

 

Has anyone to this point come out and actually said with absolute certainty that the EEC will generate the 6th order polynomial equation needed to calculate airflow regardless of how many points are actually in the MTF table?

If so, I may have missed it, but this is good news.. makes things a lot easier!

No. It's only speculation as far as I can tell. The person to ask would be Jerry or David.

 

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think. These are just reference points for graphing the mass airs calibration and Pro-M uses 30 but only prints 9 If you want 30 printed just ask . I dont realy see why with being able to comtrole the MTF this is even an issue

Tom

Could I be misunderstanding how the MAF Transfe Function works? I thought that the ECU looks at each row, I didn't know it does it's own calculations based on whatever few (or many)points there are in the MTF to pull air measurements for even voltages.

Guess I'm going to go download that EEC whitepaper now...

If I understand this right, the MAF transfer function is called a function because it is exactly that. It is a mathematical function. The data you enter into the table is what allows the computer to calculate a function (which could be represented as a curve on a graph) that it could use to calculate an infinite number of points. If it only goes down to three places, then the function is finite. But if you understand how a function works I think you get the point.

Has anyone to this point come out and actually said with absolute certainty that the EEC will generate the 6th order polynomial equation needed to calculate airflow regardless of how many points are actually in the MTF table?

If so, I may have missed it, but this is good news.. makes things a lot easier!

Would you like to supersize that order sir? (Feeling stupid)

It is a good thing we have some of you guys around!

 

Interesting read on MAF's I stumbled on the other day: Link

And Rich...sixth order just means: ...+X^6 like in y = aX + bX^2 + cX^3 + dX^4 + eX^5 + fX^6 I'm sure you've seen that before.

What it means though, is that if you know x, you can calculate y. Or vice versa. So if x is the voltage, then y would be the coresponding flow.

 

Interesting read on MAF's I stumbled on the other day: Link

And Rich...sixth order just means: ...+X^6 like in y = aX + bX^2 + cX^3 + dX^4 + eX^5 + fX^6 I'm sure you've seen that before.

What it means though, is that if you know x, you can calculate y. Or vice versa. So if x is the voltage, then y would be the coresponding flow.

step in......listen, look around uneasily.....and quietly excuse myself after saying "o..k....that sounds about right guys"

 

Interesting read on MAF's I stumbled on the other day: Link

And Rich...sixth order just means: ...+X^6 like in y = aX + bX^2 + cX^3 + dX^4 + eX^5 + fX^6 I'm sure you've seen that before.

What it means though, is that if you know x, you can calculate y. Or vice versa. So if x is the voltage, then y would be the coresponding flow.

step in......listen, look around uneasily.....and quietly excuse myself after saying "o..k....that sounds about right guys"

Come on. Its not that complicated.

The 9 points supplied with the flow sheet are simply (x,y) coordinates that create a curve (just like the curve on a dyno). You plot them on a graph, and connect the dots with a smooth curve. For any curve, there is a mathamatical function that can describe that curve. That mathmatical function is pretty hard to come up with by hand so its usually done using computer software. You input in the 9 data points and it spits out a function like I described above. Except there would be actual values for the a, b, c, d, e, & f. Once you have that function, you can enter one of the variables to determine the other.

If x = MAF voltage
and y = flow

Then if you enter in a voltage number and it will tell you what your flow is.

Now you take the function that you just determined to describe your MAF flow characteristics, and enter in the voltage values that you want coresponding flow numbers for in your 30 point MAF transfer function table.

I'm not the best at describing math and I am in no way a math major so feel free to correct me if I'm wrong or unclear...

But if you can get a 30 point flow sheet from Pro-M like Tom says, that would make life much easier.

 

How do we go about getting these 30 Point prom flow sheets? I bought mine from CFM, would contacting them get what I need? Or is this something I should be going through directly Pro-M?

 

I've re-read through the thread, and I think there is some statements that could be misleading. from what some people were saying, it's like you don't even need the 30 points of the MTF for the car to run perfectly.. just enter the 9 points, and somehow the ECU has the wherewithall to determine the function that describes the MTF.

For example, Tom's following statement is a bit confusing:

The ECU looks at the MAF at every .000 voltage NOT at the 9 or the 30 points that they are calibrated at like some would have you to think.

this leads me to believe that the MAF only looks at 5 points along the 5v curve at 0.000, 1.000, 2.000, 3.000, 4.000 and 5.000, but it should be interpretted as the EEC seing everything from 0.000 to 5v in .001 increments... and even then, the EEC software (or SCT as it were) sees everything in analog-digital counts (take voltage, and multiply by 205), and has 30 elements in the MTF table to describe the function. It doesn't matter where the points lie on the A/D axis, so long as you cover the 5 volt range of the MAF to your satisfaction.

Couple that with the statement:

There seems to be some confusion on this point. It doesn't matter how many sample points are used when calibration is done on the MAF. That does NOT define the Transfer Function table in the PCM. The Transfer Function in the PCM ALWAYS contains 30 mapped points. These values in the PCM need to be matched to the output of the MAF (Aftermarket or OEM).

The Aftermarket MAF does this in the opposite direction. By "calibrating" it's output to the STOCK transfer function with a shift in values to compensate for different sized injectors. It is then CHECKED at 9 points. That doesn't alter the 30 points in the PCM. If you ordered an Aftermarket MAF calibrated to STOCK injectors it should closely match the OEM MAF output.

and people are led to believe that the 30 points in the Mass Transfer Function don't seem to matter... and that's sort of misleading...

couple the two arguments together, and one gets the impression that the EEC is able to calculate the MAF function from whatever points are available in the mass transfer function table.. wether it be from 9 points, or 30.

Which I'm pretty sure is not the case. Though I wouldn't mind being proven wrong... I'm still just learning.

So regardless of how many points pro-m gives you, you still need to create a MAF transfer function to make it work. You could get away with just calibrating the engine displacement for the injectors that the MAF is calibrated for, but you still have to go back and tweak the MAF transfer function.. .


I think that it really boils down to the following:
Regardless of how you slice this pickle, you still need to enter in 30 points worth of data into the MAF Transfer Function with your MAF. with an aftermarket MAF, you can get them from a 30 point flow sheet you request from pro-m, or you figure it out from the 9 point sheet they give by default--draw your own graph, figure out your own equation and make it work. If you go ford oem, the values are easily available in files and are 99.99% correct.

p.s.
if you have a hard time drawing graphs and coming up with your 30 point maf transfer function from the pro-m flow sheet, check out this excel spreadsheet ... it's the closest 'automated tool' I could find, but it's not perfect. You'll need to subscribe to the yahoo newsgroup to make it work.

I found this link in this article .. both good reads if a bit advanced.

 

Man you guys are gonna kill some brain cells in a noob

I had a Pro Flow MAFS when i first got my car after reading Dennis W , back in hte day, posted about getting 14hp or so from one.

I do know when you order one it is calibrated to your cars year, and your ecu code, and what type of filter you are using. Pretty car specific like a chip.

The first one i had seemed to work great. but i got rid of it for some odd reason thru all my changes.

I then ordered another and they asked all the information i listed, its seemed ok but no great difference. I then read the tuning book and they said it really did nothing, so i swapped back my stock one and the car ran better.

I will say the readouts they send you for both of the ones i had were different with a different COB code and my car hasnt changed.

I was at New EDGE when TOny got a shipment of 3 in a few years back and each one had a different COB code and didnt mention what year car they were for either.

I personally think its a Hit or Miss on them.

But Talking to Ray at McNews, he has a Mafter burner type unit so you can program the MAFS and fine tune it. Id say thats the best way to go.

I believe Toms test all his so he knows, they have the correct calibration needed. Cause I think Tom used to get 10 in at a time from ProFlow and have to send a few back.

But like tom said unless you are runing out of injector or make alot of HP you really dont need it.

Just my Big .02

 

Come on. Its not that complicated.

The 9 points supplied with the flow sheet are simply (x,y) coordinates that create a curve (just like the curve on a dyno). You plot them on a graph, and connect the dots with a smooth curve. For any curve, there is a mathamatical function that can describe that curve. That mathmatical function is pretty hard to come up with by hand so its usually done using computer software. You input in the 9 data points and it spits out a function like I described above. Except there would be actual values for the a, b, c, d, e, & f. Once you have that function, you can enter one of the variables to determine the other.

If x = MAF voltage
and y = flow

Then if you enter in a voltage number and it will tell you what your flow is.

Now you take the function that you just determined to describe your MAF flow characteristics, and enter in the voltage values that you want coresponding flow numbers for in your 30 point MAF transfer function table.

I'm not the best at describing math and I am in no way a math major so feel free to correct me if I'm wrong or unclear...

But if you can get a 30 point flow sheet from Pro-M like Tom says, that would make life much easier.

thanks, that was perfect.............for future reference sock puppets help me learn as well....