sdbrown84

iTrader: (22)

I took a SLP MAF and De-modded it, removig the resistor between the ends.

Does anyone have a starting frequency table for the 85mm swap using HP Tuners?

Thanks.

Engine_HP

iTrader: (1)

@@ im looking for the same thing.

jimmyblue

iTrader: (11)

Just download a stock 6.0 truck tune file from the repository.
Though some are "cleaner" than others at the very low end,
lack of discontinuities etc., you should never see an output
frequency below about 2000Hz so one's about as good as
another.

Here is a zipped Excel 'sheet with various MAF tables. You want
to use either the Z06 or "Zl1 truck" row, Z06 is slightly leaner and
truck slightly fatter, go by which one gives you closer commanded:
actual fueling.

2002_Z28_Six_Speed

iTrader: (19)

Be wary of using anything as is. Any modification to the air intake path or MAF itself and you might as well totally recal the MAF yourself.

sdbrown84

iTrader: (22)

Thank you jimmyblue, I just need a starting point for tuning.

How do you tune in the MAF properly with HP Tuners?

Thanks.

2002_Z28_Six_Speed

iTrader: (19)

You need to log AFR error (bin) with a WB O2 and compared that to logged frequency!

69LT1Bird

iTrader: (1)

I got this directly from Greg Banish and it works great and it is very easy. It is for a MAF only tune. It assumes every thing else is tuned already.

The min threshold for steady state rpm is located in Engine|Airflow|Dynamic Air|Hi/Lo RPM Thresh, set to zero

The minimum temp setting is in Engine|Fuel Control|OL&CL|Closed Loop Enable vs IAT. set all cells to 284.

Use the MAF to AFR Error histogram that is already in HP Tuners. Log some data and copy paste special is way off or by half if within 10. When satisfied, reset the two settings above and reflash and drive.


"If you have the fuel injector data correct, you can develop the MAF transfer function based on wideband a/f error. Just lock the car into open loop (set min temp for CL to max) and force MAF based operation (min threshold for steady state to 0rpm) and work from there. You should be able to start with the stock MAF curve, but you'll quickly see the trend where it must be adjusted to get fueling in line. You will eventually develop the new MAF transfer function for that metering element in whatever inlet tube you've installed it. Once the MAF is right, you'll find that lots of other things just fall into place."
Greg Banish

Engine_HP

iTrader: (1)

Q. why is the zo6`s 85mm maf has a lower numbers Frequency Tables than the f-body75mm ?

isn`t is suposed to be higher ?

2002_Z28_Six_Speed

iTrader: (19)

Due to cross sectional area, if you are comparing on a frequency basis.
Lower cross sectional area has a higher flow rate at a given speed than a larger cross sectional area for the same MASS FLOW RATE.

so this means more cooling effect earlier (at a lower frequency) directly acrost the cooling elements of the MAF.

But look the Z06 still outflows.


My friend's 4.3L MAF seriously pulls 6K Hz driving around normally.

2002 Z06
LABELS MAF Sensor Calibration (Grams/Second)
Hz {link: GM.MAFFREQ} Value
1500 1.421875
1625 1.757813
1750 2.101563
1875 2.484375
2000 2.859375
2125 3.257813
2250 3.695313
2375 4.179688
2500 4.710938
2625 5.312500
2750 5.968750
2875 6.679688
3000 7.429688
3125 8.226563
3250 9.078125
3375 9.968750
3500 10.914063
3625 11.929688
3750 13.054688
3875 14.273438
4000 15.585938
4125 16.984375
4250 18.468750
4375 20.046875
4500 21.718750
4625 23.476563
4750 25.335938
4875 27.281250
5000 29.335938
5125 31.484375
5250 33.742188
5375 36.109375
5500 38.617188
5625 41.296875
5750 44.171875
5875 47.203125
6000 50.398438
6125 53.765625
6250 57.296875
6375 61.007813
6500 64.875000
6625 68.914063
6750 73.117188
6875 77.468750
7000 81.968750
7125 86.632813
7250 91.453125
7375 96.429688
7500 101.585938
7625 106.898438
7750 112.359375
7875 118.007813
8000 123.828125
8125 129.843750
8250 136.046875
8375 142.476563
8500 149.125000
8625 155.984375
8750 163.062500
8875 170.375000
9000 177.921875
9125 185.703125
9250 193.726563
9375 201.992188
9500 210.515625
9625 219.296875
9750 228.335938
9875 237.640625
10000 247.226563
10125 257.062500
10250 267.164063
10375 277.562500
10500 288.250000
10625 299.250000
10750 310.554688
10875 322.195313
11000 334.156250
11125 346.492188
11250 359.164063
11375 372.218750
11500 385.656250
11625 399.507813
11750 413.765625
11875 428.453125
12000 443.601563


LABELS MAF Sensor Calibration (Grams/Second)
Hz {link: GM.MAFFREQ} Value
1500 2.320313
1625 2.695313
1750 3.148438
1875 3.648438
2000 4.164063
2125 4.726563
2250 5.359375
2375 6.054688
2500 6.804688
2625 7.640625
2750 8.531250
2875 9.468750
3000 10.429688
3125 11.445313
3250 12.562500
3375 13.781250
3500 15.085938
3625 16.492188
3750 17.984375
3875 19.578125
4000 21.257813
4125 23.031250
4250 24.906250
4375 26.882813
4500 28.953125
4625 31.132813
4750 33.398438
4875 35.781250
5000 38.281250
5125 40.929688
5250 43.726563
5375 46.687500
5500 49.796875
5625 53.070313
5750 56.507813
5875 60.109375
6000 63.875000
6125 67.804688
6250 71.898438
6375 76.156250
6500 80.578125
6625 85.156250
6750 89.906250
6875 94.828125
7000 99.929688
7125 105.195313
7250 110.648438
7375 116.281250
7500 122.117188
7625 128.148438
7750 134.382813
7875 140.867188
8000 147.585938
8125 154.531250
8250 161.718750
8375 169.148438
8500 176.820313
8625 184.734375
8750 192.820313
8875 201.148438
9000 209.742188
9125 218.609375
9250 227.773438
9375 237.257813
9500 247.078125
9625 257.273438
9750 267.859375
9875 278.875000
10000 290.343750
10125 302.312500
10250 314.812500
10375 327.882813
10500 341.562500
10625 355.906250
10750 370.953125
10875 386.757813
11000 403.359375
11125 420.828125
11250 439.203125
11375 439.203125
11500 439.203125
11625 439.203125
11750 439.203125
11875 439.203125
12000 439.203125

jimmyblue

iTrader: (11)

The cal curve of the 85mm is simply different. The housing and
electronics are not the same. So you have a MAF that flows
better, but hits some electrical / software limits at a lower max
flow.

If you were to hog out a 85mm unit you could get it to a point
where the 511g/sec and 12kHz limits coincide, which is the best
you can do in this system. However when I did this, I had to cut
out the center vane and hog out the periphery and the result
was some pretty unstable output frrequency behavior. May have
to do with my cam / TB / intake, or not. At any rate a stock
internal, stock cube, NA motor turning under 7000RPM is not going
to max out the MAF so I'd just pop the screen and tweak up the
tables until you get the right answer.

However before you go doing that you might want to spend some
time baselining things with the stock MAF (which ought to be
dead-on, if screened and clean) and allow you to determine
whether you have any other embedded errors (like fuel delivery)
that want to be trued up first. You don't want to make the MAF
table try and represent a dirty fuel filter, and like that. One
thing at a time from a clean solid base, is how you stay out
of the spaghetti.