2016 Camaro E92 MAF Scale question.

[PRAY]

I was building a base tune file for my Camaro yesterday when I noticed that the MAF table goes to 8500hz and then skips to 15000. There is no data shown or scale shown in between. The MAF Freq 2 table is complete so I though it was a glitch or something but apparently it is the same with HPT. Is there a way to show this data or re-plot the scale to show it. I dynoed the car stock today and it hit 8400hz. I am going to need the rest of that table to do any mods to this thing. I am assuming that if there isn't a way then I will just add what ever percent to the 15000 slot that I did to the 8500 slot and hope the computer adjusts the curve? I know I can just hit the PE table or the VVE tables I guess but I would like full control over all of the fueling tables.

[joecar]

May I see your tune file...?

[PRAY]

Yes Sir,

20038

Thanks Joe

[PRAY]

I haven't seen people mention this as an issue yet but I know there are a bunch of forced induction products going on these cars so there has to be a way around it. Most of my H/C cars see into the 10K hz range. My stroker motors make it into the 11K range.

Joe, something else I noticed is missing from that I had access to in the C7 files is B2524 BTM Torque Limits. It doesn't exist in the Camaro file under the Torque Control tab. IIRC, that table has something to do with how fast the throttle blade opens going to WOT.

[joecar]

Yep, B1099 does not look right, I'll alert Paul.

[PRAY]

Yep, B1099 does not look right, I'll alert Paul.

Thank you Sir. If anything can be done about the BTM table as well that would be great. That is all I have noticed so far as dufferences.

Is there a way for me to make a table with the missing areas in the mean time?

[GMPX]

Yeah I agree I wouldn't expect the axis to increase at the rate it is, I'll have it checked out.

[GMPX]

We double checked the definition of the MAF tables and they are correct, I don't know what GM was thinking with these but it is like they wanted high resolution under 8550 Hz and then beyond that there is a VERY steep linear blend to 15,000 Hz. It could also be computer model generated numbers which is why they look uneven to what we are normally used to seeing.

[joecar]

And GM provided MAF #2 table B1100 which looks ok (axis range does not jump)...

how do you go about running this table instead...?

[joecar]

And GM provided MAF #2 table B1100 which looks ok (axis range does not jump)...

how do you go about running this table instead...?
I'm wondering if MAF #2 has an ECM pinout...

[Redline Motorsports]

We double checked the definition of the MAF tables and they are correct, I don't know what GM was thinking with these but it is like they wanted high resolution under 8550 Hz and then beyond that there is a VERY steep linear blend to 15,000 Hz. It could also be computer model generated numbers which is why they look uneven to what we are normally used to seeing.

It is correct it needs to be rescaled....we've been able to stretch the MAF to 17000 hertz without hitting a wall.

[GMPX]

Thanks Howard.

[PRAY]

Thanks Howard. Can someone explain how I rescale it or point me to where I can read up on it. I looked through what I could find in the software and wasn't able to adjust the scale. I don't want to mess anything up so I figured it better to ask. Thanks.

[SPi]

Running into this alot now, especially with the 2017's . Can someone explain how to rescale the MAF table. I've done it in other software, can't see how it's done in EFI

[joecar]

Running into this alot now, especially with the 2017's . Can someone explain how to rescale the MAF table. I've done it in other software, can't see how it's done in EFI
Post your tune file.

~Moderator~

[SPi]

Here you joecar. Both MAF tables display that large spike

[joecar]

Here you joecar. Both MAF tables display that large spikeIt's not really a spike... look at how the axis jumps from 9600 Hz to 15000 Hz.

[joecar]

Running into this alot now, especially with the 2017's . Can someone explain how to rescale the MAF table. I've done it in other software, can't see how it's done in EFIAre you running out of MAF airflow g/s...?

Your tune file shows that it supports up to 3000 g/s.

[SPi]

It's that jump in the axis I am talking about. Is it possible to rescale that axis to obtain better resolution in the higher area? Im not running out Maf, but that big jump makes it difficult to dial it in. 20949

[joecar]

I'm told that GM put that jump in there... it's not possible to rescale the axis.

[SPi]

OK thanks joecar

[EFI Tuning]

I'm told that GM put that jump in there... it's not possible to rescale the axis.

It's possible. Just not with EFI Live ;) GM did it the way they did to maximize the resolution of the actual operating range.

[Wichita Dyno]

So what is the latest on this? Can we not rescale with this software?

[Wichita Dyno]

So I will take it the silence means no?

[SPi]

It can be rescaled, just not with EFI Live yet

[Blacky]

So what is the latest on this? Can we not rescale with this software?

The MAF axis is just a non-visible calibration in EFILive. I don't see any reason why it can't be made visible so it can be re-scaled by the tuner. I'll add it to the list of things for the next update.

Meanwhile the way it currently determines the lookup values from the MAF table between 8550 and 15000 is via linear interpolation.

For example assuming the last two entries in the table are:
8550=360
15000=1150
then if the Hz value was 12000, then the value returned from the lookup table is computed by the ECM as follows:

g/s = 360+v*(y/x) where
v = 12000-8550
y = 1150-360
x = 15000-8550

so the lookup value when Hz=12000 is calculated as: 360+(12000-8550)*(1150-360)/(15000-8550)
360+3450*(790/6450) =
360+3450*0.12248 =
782g/s

To help with tuning right now, here's what the values are for various points in between the last two cells:


Hz g/s
8550 360
8600 366
8650 372
8700 378
8750 384
8800 391
8850 397
8900 403
8950 409
9000 415
9050 421
9100 427
9150 433
9200 440
9250 446
9300 452
9350 458
9400 464
9450 470
9500 476
9550 482
9600 489
9650 495
9700 501
9750 507
9800 513
9850 519
9900 525
9950 531
10000 538
10050 544
10100 550
10150 556
10200 562
10250 568
10300 574
10350 580
10400 587
10450 593
10500 599
10550 605
10600 611
10650 617
10700 623
10750 629
10800 636
10850 642
10900 648
10950 654
11000 660
11050 666
11100 672
11150 678
11200 685
11250 691
11300 697
11350 703
11400 709
11450 715
11500 721
11550 727
11600 734
11650 740
11700 746
11750 752
11800 758
11850 764
11900 770
11950 776
12000 783
12050 789
12100 795
12150 801
12200 807
12250 813
12300 819
12350 825
12400 832
12450 838
12500 844
12550 850
12600 856
12650 862
12700 868
12750 874
12800 881
12850 887
12900 893
12950 899
13000 905
13050 911
13100 917
13150 923
13200 930
13250 936
13300 942
13350 948
13400 954
13450 960
13500 966
13550 972
13600 979
13650 985
13700 991
13750 997
13800 1003
13850 1009
13900 1015
13950 1021
14000 1028
14050 1034
14100 1040
14150 1046
14200 1052
14250 1058
14300 1064
14350 1070
14400 1077
14450 1083
14500 1089
14550 1095
14600 1101
14650 1107
14700 1113
14750 1119
14800 1126
14850 1132
14900 1138
14950 1144
15000 1150



Regards
Paul

[joecar]

Paul, thanks!

[Blacky]

Here's what the entire table (when extrapolated) would look like when plotted in Excel.

20989

Regards
Paul

[joecar]

They go linear above 8500Hz...?

[Blacky]

They go linear above 8500Hz...?

Yes. All data between cell values in all tables is interpreted using linear interpolation.
https://en.wikipedia.org/wiki/Linear_interpolation

Regards
Paul

[joecar]

( so this makes me wonder how GM process the error between MAF and VE, besides the dynamic air threshold how do they determine which to use )

~ by phone ~