I took the average of 5 logs, all from the same day about about 3 hours worth, and combined them to form an average. For the values I didnt have above 10khz I used excels fill feature to estimate their value. I plotted this graph over the stock graph and this is what you see below. I logged dynamic airflow vs frequency.



I was expecting more a difference...the values above 10khz I understand because excel is using a linear function instead of a 2nd or 3rd (which fits the stock graph perfectly) polynomial. Since I can't get close to these values, even at WOT, should I really worry about it considering im not boosted (yet....).

* Does this look right for an LM7 5.3 with intake, pacesetter longtubes, and 3" pipe?
* Should I go about fine tuning this with STFTs? If so, could you elaborate how? I have my VE table dialed in to +/-2% on the STFTs with the LTFTs in the 1 to -4 range.

 

Do you have a wide band? Log the commanded to the accual in PE(below 14.6) use the error to make corrections.

 

He is. But he is curve fitting.


To the OP:

Why not try trending with a higher polynomial? It will still kick out the notchyness and make a nice smooth curve.

 

Ah, just found out how to do that.

Should a recalibrated MAF table be that close to the stock one or am I doing something wrong? I dont have a wideband yet, but is my method of using dynamic airflow vs frequency not accurate? It produced numbers very similar to the stock data...

 

I just made this one real quick using growth fill instead of linear. I also graphed the percent difference in the one I made and the stock table... is the factory maf really that close (aside from the 3000 to 4000hz range) even with mods?

 

Dynamic flow from what? SD?

 

The sensor...Dynamic Airflow in g/sec

But yes I was running in SD with the maf failed, but still plugged in so my IAT sensor works.

 

Well how much is the stock VE tuned?

 

None, stock as in...stock...nothing changed from factory.

 

2002 z28 if you want to help make sure you know what they are doing. Atomic you have to have something to verify against. If you dont have a wideband what are you verifing against. What are you tring to do? I am not sure I understand?

 

Calibrate my MAF. I have my VE table well dialed in so I am trying to calibrate my MAF to reflect that. What I graphed was my calculated maf table versus the stock table and was noting the difference between them (or lack there of) is very small.

 

Sounds like you two guys are the confused ones to me. Good luck.

 

Ok, put another way, how much of a difference is there between a MAF calibrated for bolt ons, and a stock MAF on a Gen III ls1 based engine?

 

Interesting. Let's compare.

This is my car:
LM4 5,3L
Pacesetter headers and Y
Hooker Catback
LS6 intake
Air lid
Z06 cam.


LABELS MAF Sensor Calibration (Grams/Second)
Hz {link: GM.MAFFREQ} Value
1500 2.953125
1625 3.062500
1750 3.273438
1875 3.593750
2000 4.000000
2125 4.484375
2250 5.023438
2375 5.570313
2500 5.570313
2625 4.648438
2750 5.273438
2875 5.679688
3000 6.406250
3125 7.203125
3250 8.367188
3375 9.382813
3500 9.960938
3625 11.070313
3750 11.960938
3875 12.890625
4000 14.367188
4125 15.070313
4250 17.085938
4375 18.132813
4500 20.093750
4625 21.898438
4750 23.523438
4875 25.828125
5000 27.625000
5125 29.484375
5250 31.164063
5375 33.671875
5500 38.765625
5625 39.367188
5750 45.312500
5875 46.234375
6000 47.039063
6125 51.359375
6250 60.109375
6375 60.593750
6500 66.390625
6625 69.007813
6750 69.843750
6875 75.531250
7000 82.492188
7125 86.390625
7250 85.031250
7375 93.273438
7500 98.421875
7625 102.968750
7750 104.648438
7875 109.804688
8000 118.007813
8125 127.867188
8250 131.000000
8375 135.390625
8500 145.570313
8625 156.968750
8750 169.992188
8875 174.343750
9000 183.007813
9125 197.671875
9250 200.921875
9375 210.695313
9500 223.718750
9625 233.484375
9750 236.742188
9875 249.765625
10000 253.023438
10125 259.648438
10250 272.070313
10375 284.078125
10500 295.648438
10625 307.148438
10750 318.617188
10875 329.757813
11000 340.242188
11125 349.992188
11250 359.351563
11375 368.859375
11500 379.132813
11625 390.312500
11750 401.656250
11875 411.351563
12000 417.031250


what is the engine in? what pcm are you using? stock camaro calibration or stock 5,3 calibration?

I think by 5K Hz or so the Delta MAF can't tell you much. It is coming from stock O2s which can't tell you anything after the AFR has varied more than a couple of points.