2006 ls2 vette with heads, cam, exhaust CAI

what is the high range of the MAF frequency in HZ that I can expect to see? I did a quick WOT pull on the street and saw 7.40, didn't log anything over that. Note I'm running the ls3/7 card MAF if that matters.

 

You are logging something other than HZ if you are reading 7.40. Probably lb/min. Typical MAF HZ output is 2500-12500 HZ (idle-wot).

 

Sorry, typo. Meant 7400. So I am calculating data from 2000-7600 (idle-WOT)

 

7400 HZ or RPM?

 

sorry let me try to be clear.

so in HPT I am logging lambda error in a histogram to adjust MAF airflow vs Output Feq table. the X axis is Mass Air Flow Feq (hz) and Y axis is airflow

when logging I am only collecting data in the histogram between 2000 and 7600 hz which is idle to WOT

I'm just wondering if that is about the max that I will see on a NA car or was my WOT pull to short

 

did a much bigger wot pull just now and recorded data all the way to 8600, but shouldn't it record to 10,000?

my lambda errors across the range are all small, on average less than 1.0

 

My 6.0 with long tubes and ls6 intake/cam is pulling over 11,000hz on an unmodified 85mm stock maf. Yours sounds very low, you might want to try another maf and do another log session. Even 2000 at idle sounds low, I was at almost 4000 at idle before I installed a resistor to bring it down, now sitting at around 2500.

 

well I just drove it on the track and I threw code PO101. Car ran fine all day (actually very good) until the code. I'm wondering if I'm getting a bad signal or the MAF got dirty? Or something else? Fuel usage went to all hell.

I am running the card stye ls3/7 MAF with harness adapter. Is there a certain ls 3/7 MAF that I should be looking for?

 

Looking at Rockauto it appears an 06 Vette w/LS2 still used the 85mm 5 wire MAF sensor.(truck MAF) When you switched to the LS3/7 MAF did you change the MAF table in the tune for it?

 

yes and have tuned it using lambda error as well

here is the MAF I am using. According to the website I have the strong maf as my code is K23. Also notice it states the strong has a 8600 MHZ signal at WOT. My MAF has a sticker on it that says REMFG

Question. The MAF itself can only go in to the KnN holder one way, but does it matter what part of the MAF is facing up? I notice an arrow on the MAF, should that point toward the TB or Air filter?

 

ok one more question for the experts

I'm running a catch can and have a line tied into the CAI. The fitting for the line sits across and near the MAF. Can that disrupt, alter, screw up the MAF readings enough to throw that error code?

 

Depends on where the other end of that line goes. Any line in front of the TB blade as part of the PCV system should be going to a valve cover nipple.

 

yes that is where it goes

 

I don't have any experience with that style maf, but beings that it has a much different range than the original maf, it either may not be compatible, or you'll have to modify the DTC checking parameters to get everything within range. Have you tried using an 85mm maf to see if the problem goes away?

 

Don't have one laying around.

What do you mean "modify DTC checking parameters"

So since I am running the ls3/7 MAF I loaded the MAF data from a stock ZO6. With that I was able to get the car started, driving and made adjustments using lambda error. But now wondering if the data points on the X axis (MAF HZ) are off and if that would matter. I didn't get the PO101 code until after many hard runs. Why would it run, drive, idle fine at all if the ranges were off? Maybe it's just the WOT MAF high range?

I posted over at HPT as well. Thanks

 

You have LS3/7 MAF and the arrow on the MAF does matter. That's the direction of the airflow. So it needs to be pointing towards the throttle body.

 

Ok, looking at a 09 LS3 MAF table which should be the same one as the LS7 card style, looks like it has a range of 0-15,000, and your stock tune has two tables, the higher one maxing out at 12,200.

I think I found your problem... the max your computer will see is 511.9922 g/sec, but at 511 g/sec that style maf is only reporting around 9750hz, well below your max of 12200. So you're maxing it out WAY too early. So there's where I believe your problem is your problem is. That MAF isn't going to work right for your application IMO.

 

ok I hear you and thanks for looking into to it.....but....I just compared the MAF table from the ls2 tune to the stock ls7 tune. Both have E38 ECM's and both have the same low and high tables. I doubt I will ever see the max of 511 g/sec and currently seeing around 8600hz max.

 

Im showing two different operating systems between both cars even though theyre both E38 ECMs. The OS Im seeing for an 06 Auto LS2 vette is $DB130448, for an 09 LS3 auto is $A5BE545C. Looks like the LS2 operating system in both of your pictures, as the LS3 only has one MAF table. Id bet you have the wrong MAF data.

Heres the MAF data from the LS3 vette file. You can see, even the format is different. Though you should be able to put most of these numbers in and it should get you pretty close, just match the closest frequency to whats in your table and smooth it by hand.

LABELS MAF Frequency Conversion (Grams/Sec)
Hz Value
0 0.389765
150 0.389765
300 0.389765
450 0.389765
600 0.389765
750 0.389765
900 1.025958
1050 1.700490
1200 3.494886
1350 3.890867
1500 4.438219
1650 5.136941
1800 5.987034
1950 6.988497
2100 8.141331
2250 9.445535
2400 10.920454
2550 12.579458
2700 14.414942
2850 16.469835
3000 18.748518
3150 21.245575
3300 23.970362
3450 26.917643
3600 30.087465
3750 33.482204
3900 37.100533
4050 40.958755
4200 45.120026
4350 49.549770
4500 54.247997
4650 59.214699
4800 64.640617
4950 70.448959
5100 76.611755
5250 83.143051
5400 90.055779
5550 97.338379
5700 104.984428
5850 112.992119
6000 121.397011
6150 130.430023
6300 139.983246
6450 150.056656
6600 160.645737
6750 171.664383
6900 183.166779
7050 195.152908
7200 207.590057
7350 220.468414
7500 233.803955
7650 247.782623
7800 262.518555
7950 277.900299
8100 293.844818
8250 310.371948
8400 327.387024
8550 344.738281
8700 362.599182
8850 381.681396
9000 401.485687
9150 422.261963
9300 445.866180
9450 467.670868
9600 490.191864
9750 513.441040
9900 537.430359
10050 562.171631
10200 587.676819
10350 613.957764
10500 641.026428
10650 668.894592
10800 697.574280
10950 727.077271
11100 757.415588
11250 788.601013
11400 820.645447
11550 853.560852
11700 887.359070
11850 922.052002
12000 957.651611
12150 994.169678
12300 1031.618164
12450 1070.008911
12600 1109.353882
12750 1149.665039
12900 1190.954102
13050 1233.233032
13200 1276.513672
13350 1320.808105
13500 1366.127930
13650 1412.485352
13800 1459.892090
13950 1508.360107
14100 1557.901123
14250 1608.527344
14400 1660.250366
14550 1713.082275
14700 1767.034912
14850 1822.120117
15000 1878.349731

 

Heres a screen cap...