PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

MAF frequency stops at 5250?

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Old Jan 29, 2022 | 04:58 PM
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Default MAF frequency stops at 5250?

Is the MAF frequency supposed to stop at 5250hz? I have noticed it before, but didn't really pay attention.
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Old Jan 30, 2022 | 09:06 AM
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I think all F body MAF stop at 12000hz. My 2000 does anyway
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Old Jan 30, 2022 | 11:10 AM
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HP Tuners shows cells up to 12k, but nothing above 5250hz populates.
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Old Jan 30, 2022 | 11:18 AM
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You mean it doesn't populate in the scanner or histogram?
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Old Jan 30, 2022 | 11:20 AM
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Can you post a log and tune so we can see what you are talking about?
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Old Jan 30, 2022 | 11:23 AM
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Originally Posted by LilJayV10
Can you post a log and tune so we can see what you are talking about?
Histogram does not populate in the scanner
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Old Jan 30, 2022 | 11:25 AM
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Are you logging the correct MAF pid? Does it show up in the graph while its running?

If the answer is Yes to both, I would guess the histogram is not setup correctly and/or there's a filter being used.

Post up a log.
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Old Jan 30, 2022 | 12:17 PM
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I have an LS7/3 card MAF sensor in a 5" housing.

log attached
Attached Files
File Type: hpl
1-28-222_2.hpl (1.66 MB, 50 views)
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Old Jan 30, 2022 | 07:12 PM
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Here is the tune too, if that helps. This is the tune that was being used for logging.
Attached Files
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Old Jan 30, 2022 | 07:43 PM
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Crap, I just saw your WB in the channel list..............

Brb

Last edited by LilJayV10; Jan 30, 2022 at 08:02 PM.
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Old Jan 30, 2022 | 08:18 PM
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This is the way I do it.

Go to your chart and add EQ commanded
Then add EQ Error, it's under 'Math'-'Lambda/AFR'-EQ Err

Then open up a new graph, select EQ Err
In Column axis, select MAF frequency
Copy the MAF column from your tune, past into the graph.

It will show the EQ Err in each cell of the MAF

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Old Jan 30, 2022 | 08:23 PM
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I set it up off your log file and it works like it should.

If you have any other questions let me know.
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Old Jan 31, 2022 | 07:15 PM
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What does function [50090.156] do?
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Old Jan 31, 2022 | 07:21 PM
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Originally Posted by FCar2000TA
What does function [50090.156] do?
You can actually ignore that, I deleted part of it but not the whole thing for some reason.

It's a filter.

50090.156 is the TPS, what I had originally was 50090.156 >90%

I was tuning WOT, with the >90%, the histogram won't start populating any data until the TPS is above 90%. It just cleans the histogram up and makes the copying/pasting easier because it filters out all the idle/part throttle part of the log.

You can add all sorts of filters, TPS, RPM, boost, etc.
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Old Jan 31, 2022 | 07:47 PM
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Are you boosted yet or just running NA for nw? An ls7 MAF in a 5 inch pipe may ny see higher frequencies until you add some boost.
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Old Jan 31, 2022 | 07:55 PM
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NA for now. 5" tube is for later on down the road. I needed to replace it anyway, so I figured "might as well".
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Old Jan 31, 2022 | 07:59 PM
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I'm guessing you aren't hitting any higher Hz because of the size of the tube and you really didn't get above 5 grand.

The MAF is following the RPM's so I would think everything is working as it should.
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Old Feb 13, 2022 | 11:42 AM
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i agree with liljay. going from a 4 to 5" intake will increase the area by over 50% which will reduce the velocity by 50%
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Old Feb 13, 2022 | 12:11 PM
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Originally Posted by cpressl90
i agree with liljay. going from a 4 to 5" intake will increase the area by over 50% which will reduce the velocity by 50%
I did a bunch of logging, tuning, logging, repeat... seems to be getting better with each round. Just concentrating on driving in town, so I'm just looking at the cells under 4625hz. All but two are staying under 2%, and most are under 1%.
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Old Feb 13, 2022 | 12:50 PM
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you are losing resolution with the large intake but 2% is good, fuel trims will take care of the rest.
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