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MAF scale adjustment

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Old Sep 11, 2010 | 04:22 PM
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Default MAF scale adjustment

I know it's been discussed before, but bear with me;
I TRYING to tune a 98 C5 H/C blower car. I am working on getting the MAF calibration (I swapped to Z06 MAF) because my fueling is off BIG TIME at WOT. I'm getting closer, but I notice my mounted gauge going lean (high 12's and 13 flat) toward the end of a run and back off fast.
It turns out my MAF scale runs out.... My final Hz reading is 11200, and I am seeing 13376 at 5400! I've heard that you have to "trick" it some way, but can't find the exact answer.
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Old Sep 11, 2010 | 09:05 PM
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MAF patch... Search on hptuners
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Old Sep 12, 2010 | 12:37 AM
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Just try richening the PE table at those rpms to cover it.
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Old Sep 12, 2010 | 07:28 AM
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Go to HP Tuners site and search for injector and MAF scaling.
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Old Sep 12, 2010 | 12:12 PM
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Originally Posted by Sunny
Just try richening the PE table at those rpms to cover it.
I have bumped my PE, starting at 5200, to a ratio that would take it from 14.7 to 10.5 (safety first as the starting point), which is the same as the amount that would make offset the difference from the 13 recorded to the 10.5 I need to start at, but have held off testing until I heard back.
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Old Sep 12, 2010 | 03:32 PM
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Originally Posted by kjhallex
MAF patch... Search on hptuners
I didn't really find any clear info in the search at HP, and no responses to a inquiry either...
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Old Sep 12, 2010 | 05:25 PM
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Originally Posted by kjhallex
MAF patch... Search on hptuners
there is no "MAF patch" to make a 98 or any other GenIII PCM take the MAF farther. There is only scaling or better yet, 2bar SD.
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Old Sep 13, 2010 | 07:02 AM
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Originally Posted by BOTTLE ROCKET
I know it's been discussed before, but bear with me;
I TRYING to tune a 98 C5 H/C blower car. I am working on getting the MAF calibration (I swapped to Z06 MAF) because my fueling is off BIG TIME at WOT. I'm getting closer, but I notice my mounted gauge going lean (high 12's and 13 flat) toward the end of a run and back off fast.
It turns out my MAF scale runs out.... My final Hz reading is 11200, and I am seeing 13376 at 5400! I've heard that you have to "trick" it some way, but can't find the exact answer.
Did you plug in a dump file of the Z06 frequency first? have you maxed out these tables yet?
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Old Sep 13, 2010 | 12:12 PM
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Originally Posted by moehorsepower
Did you plug in a dump file of the Z06 frequency first? have you maxed out these tables yet?
Sorry; I'm not familure with the terminalogy, or procedure
I received the Z06 MAF with the blower, so I simply installed it and dialed the MAF in.
What would it involve?

Frost

I've thought about a SD tune, just don't know about the drivability without a MAF when it goes from low 40's to high 80's in a single day down here. I was hoping to keep the MAF since 95% of my driving is just tooling around at part throttle, which works well with the VE/MAF combo.
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Old Sep 13, 2010 | 10:37 PM
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Just multiply the PE table by the percentage of leanness (.12) from 5200 up. This will take you from 13 to 11.5 then test it 1000 RPMs at a time. This is a good safe fuel ratio for a Maggie or ProCharger with 10lbs of boost or less with 16-18 degrees of timing up top.

Last edited by Sunny; Sep 13, 2010 at 11:22 PM.
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Old Sep 14, 2010 | 06:48 AM
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Originally Posted by BOTTLE ROCKET
Sorry; I'm not familure with the terminalogy, or procedure
I received the Z06 MAF with the blower, so I simply installed it and dialed the MAF in.
What would it involve?

Frost

I've thought about a SD tune, just don't know about the drivability without a MAF when it goes from low 40's to high 80's in a single day down here. I was hoping to keep the MAF since 95% of my driving is just tooling around at part throttle, which works well with the VE/MAF combo.
Since the Z06 maf is a different frequency you can get what is called a "Dump File" this list out the frequency of the MAF. Then you just start multiplying by X amount of % into your table until you get as close as possible to the Z06 File, Then I start tuning the maf from there..
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Old Sep 14, 2010 | 07:37 AM
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Originally Posted by Sunny
Just multiply the PE table by the percentage of leanness (.12) from 5200 up. This will take you from 13 to 11.5 then test it 1000 RPMs at a time. This is a good safe fuel ratio for a Maggie or ProCharger with 10lbs of boost or less with 16-18 degrees of timing up top.
I actually went ahead and made these changes to my PE table (actually put in 10.5 for safety to work my way up)but haven't tried it because I wanted to get some feedback 1st.
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Old Sep 17, 2010 | 06:10 PM
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Update;
I guess I will give up on the MAF, and go ahead and try and do a SD tune. I ordered the cobalt SS sensor and will get started
Question:
When I copy my VE over to the new VE table, since I'm blown, do I need to multiply the last line of the table by 1.25, or 1.50 and interpolate between entries?
Thanks
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