anesthes

iTrader: (12)

Any of you guys using a FORD or blower works maf?

I know they are pretty popular with the Corvette folks, but I was curious if anyone on here lurking in the shadows is using them.

I'm just looking for some feedback on the responsiveness, flow curve, if you are using the integrated MAT sensor(6 pin), etc.

-- Joe

tequilaboy

Hey Joe.

FWIW: I just logged a few no load throttle stabs to ~1/2 throttle and some stabs to WOT from idle in neutral to observe the signal response to a step input.

Logging at 8192 baud via TunerProRT, the MAF voltage step (of ~2-3 volts) occurs in the same frame as the tps voltage step (~2.5-4.5 volts). There is no observable delay in response with this method. Need an oscilloscope to really quantify the actual delay. The unlimited airflow and mass airflow signals are also in phase with both the tps and maf voltage signals. Engine rpm responds to the throttle as expected but is delayed by 1-2 data frames wrt to tps and MAF signals.

Keep in mind this test was done on a supercharged car with a bypass valve. The bypass valve is closing in synch with the throttle opening (as vacuum drops) so the blower is supplying air before the engine really responds to the throttle. A naturally aspirated car may not respond as quickly, since there is no forced air involved.

Short answer: sensor/circuit/sampling and signal processing is fast enough.

I do prefer to use the integrated IAT due to its quick response and location. Its great for logging charge air temp and also a good indicator of ambient temp. I also use it to pull timing as a function of IAT as an additional safeguard for boosted cars. Not everyone chooses to use the integrated IAT or understand the benefits. Really depends upon application and intended use.

Maf transfer functions vary with application (depending upon choice of sensor element and housing diameter). Range can vary from stock to enough to support 1,000 hp or so. The sky is the limit really.

anesthes

iTrader: (12)

Hi Pat,


I ordered a 6 wire MAF for a 2006 Mustang GT. I have a weld on bung/adapter. So I do plan on using the intergrated MAT. I'm putting it inside a 3" tube:





It appears a LOT of people are using these MAF's, but I'm having a tough time finding the voltage chart on them.

My flow curve is configurable in 64 steps. I have a flow curve for the older style (4 wire) Ford MAF's, which are 0-261 grams/sec.




The software will support MAF's up to 650 grams/sec, which is just over 920 hp.

On the blower works MAF you are using, are they basically the same Ford 4.6 MAF or are they from a lightning or ?


-- Joe

anesthes

iTrader: (12)

Found this article:

http://www.ebay.com/gds/Converting-Y...4777399/g.html


Edit: Found the flow curve for a 3" tube:

Volts kg/hour G/sec
0.311 4.83 1.3416666667
0.474 9.28 2.5777777778
0.564 11.09 3.0805555556
0.656 13.08 3.6333333333
0.719 14.89 4.1361111111
0.792 17.28 4.8
0.847 19.09 5.3027777778
0.918 21.88 6.0777777778
0.984 24.52 6.8111111111
1.088 29.34 8.15
1.175 33.8 9.3888888889
1.274 39.42 10.95
1.386 46.66 12.9611111111
1.486 53.87 14.9638888889
1.604 62.92 17.4777777778
1.74 74.09 20.5805555556
1.877 85.88 23.8555555556
2.022 100.38 27.8833333333
2.133 116.55 32.375
2.269 135.55 37.6527777778
2.423 159.04 44.1777777778
2.577 185.44 51.5111111111
2.735 216.32 60.0888888889
2.904 252.66 70.1833333333
3.07 293.72 81.5888888889
3.249 342.42 95.1166666667
3.44 400.41 111.225
3.64 466.52 129.5888888889
3.856 544.7 151.3055555556
4.079 635.91 176.6416666667
4.308 742.09 206.1361111111
4.542 864.63 240.175
4.713 963.29 267.5805555556
5 1029.09 285.8583333334


-- Joe

TTOP350

iTrader: (8)

I've read that this is doable with the newer GM style maf as well. Any truth to that?

anesthes

iTrader: (12)

Is it voltage or frequency based?

Unfortunately, ms "extra" o/s doesn't support frequency based MAF. The B&G code did, and all the MS documentation on MAF suggests using the frequency based MAF. (it's supposedly better).

James however doesn't fell this way, and as such ms2extra only supports voltage based.

If you look at the MS3 manual:

http://www.msextra.com/doc/pdf/MS3ba...rdware-1.4.pdf


You will find the code supports frequency based MAF. (which is probably why most LSx guys use MS3).

This is pure bullsnizzle, because again the older B&G code supported frequency MAF, the hardware can do it, James just felt like keeping this an "MS3 feature".


The exact same bullsnizzle surrounds the use of a VSS. Ms2extra won't do anything VSS related (although you can hook up a VSS, and record MPH, or perform some basic logic around the VSS value). Whenever someone asks why they won't put VSS logic in ms2extra since the hardware supports it, the thread gets locked.


-- Joe

tequilaboy

The extra cost of adding a maf translator to the mix makes use of a frequency based MAF somewhat impractical for these applications. Of course, it can be made to work, but why bother?

The Blowerworks slot-style mafs for the 165 ecm are indeed 05+ Ford-style analog sensors. Since the stock Ford sensor has limited range in a 3" tube, aftermarket sensors with increased range are typically used.

TTOP350

iTrader: (8)

This is what I was talking about
http://www.blowerworks.net/
then
Click on this.
Our GM L98 MAF Sensor

anesthes

iTrader: (12)

That is what we are talking about too (see thread title).

It's a Ford MAF.

Then of course, the code is modified.


-- Joe

TTOP350

iTrader: (8)

Ok, you guys are way past what I know on this, oddly I'm not much on the tuning side yet. But It sure looks like it would work.

I may just skip this and use a LS computer, coils and that custom cam and crank pickup setup.

anesthes

iTrader: (12)

For the Corvette guys, they need to keep their dash functions working which are integrated into the ECM, so the modified BIN is good for them.

I'm using an aftermarket computer, which is good for me.

-- Joe

anesthes

iTrader: (12)

Curiously, what are you seeing for voltage key-on, and at idle?

I'm seeing around .650 volts key on, engine off, and around 1.3 volts at idle.

Seems odd. Both..

-- Joe

tequilaboy

With my 350 idling at 900 rpm, ~1 volt is typical at idle. At the moment, I'm using a mid-range (3500 kg/hr) meter in a 3" housing. This meter pegs 5.1 volts around 460 gm/sec for reference.

1.3 volts for a stock Ford sensor does not sound unreasonable for your displacement.

During key on/engine off, the sensor is not powered continuously with the 165 ecm and relay arrangement, so I don't think this is a valid comparison from car to car.

At key on, the voltage spikes initially then decays after the fuel pump prime, until the engine fires and MAF is powered-up again. I will run a quick log to verify the behavior.

anesthes

iTrader: (12)

I've been troubleshooting this for hours, and I've got nowhere. The car will start and idle, but I can't rev it or it dies.

If I hold the throttle open while starting it, it will rev up, lean pop a few times, and die. What is odd is that the MAF never goes over 1.3 volts. You would think even for those brief seconds of higher RPM it would show airflow.

So assuming the MAF was bad (even know it's new), I grabbed my air gun and tested it and I can show about 3.8 volts with compressed air. So it at least reads something.

I verified all my wiring, it's got 12v, ground, sensor ground to ecu, mat to ecu, and maf to ecu. I tested the ECU inputs by shorting 5 volts and the ECU sees the maf as pegged.

The car runs absolutely amazing with MAP. I assumed with the MAF it would run even better. I can't even get it out of the shop.

I chased every wire in the harness, and when I found a sensor ground shorted to a chassis ground I thought I had won the battle, but correcting that didn't fix squat.

I'm at a loss. In theory this thing should be more responsive and run better. I just don't know what the heck is going on. I'd love to blame the ECU, but the throttle stabs should be showing voltage increase. It's almost like the engine is pulling air around the sensor not through it. Maybe the location of my sensor is pooching the whole setup.





-- Joe

tequilaboy

Sure its not in backwards? Looks like its oriented ok in the picture.

anesthes

iTrader: (12)

Yup, the flange had a little arrow showing flow direction. I made sure to weld it on the right way.

The opening in the slot with the resistor showing is away from the throttle body.

I'm using this one:

http://www.ebay.com/itm/282023029617?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
-- Joe

TTOP350

iTrader: (8)

Try to put a filter on the opening, that may be messing with things

anesthes

iTrader: (12)

I tried that yesterday.

-- Joe