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Using LS7 MAF with LQ4 harness - pinout differences

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Old 07-08-2014, 10:15 AM
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If you tuned your vehicle to run the LS7 MAF - but then put the LS1 maf back in PRIOR to re-tuning...what do you think the results would be? Lean...rich...No run at all?
Old 07-08-2014, 02:51 PM
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Originally Posted by 69MyWay
If you tuned your vehicle to run the LS7 MAF - but then put the LS1 maf back in PRIOR to re-tuning...what do you think the results would be? Lean...rich...No run at all?
For an LS1 MAF with LS3/7 tables:

Lets say the engine is injesting 180 g/s. The LS1 MAF would report 9000 Hz. The LS3 tables however would interperet 9000 hz as 400 g/s. The PCM would then fuel to 400g/s, which wold cause a rich condition(cause your only really getting 180g/s.)

In the lower airflow regions, the tables aren't too disimilar, so it might not be that bad until you get into high load/rpm regions.
Old 07-08-2014, 03:10 PM
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Originally Posted by JetMech442
For an LS1 MAF with LS3/7 tables:

Lets say the engine is injesting 180 g/s. The LS1 MAF would report 9000 Hz. The LS3 tables however would interperet 9000 hz as 400 g/s. The PCM would then fuel to 400g/s, which wold cause a rich condition(cause your only really getting 180g/s.)

In the lower airflow regions, the tables aren't too disimilar, so it might not be that bad until you get into high load/rpm regions.
Thank you! That helps explain. I often get what will cause something to go lean or rich backwards in my head.

And...if you just leave it unplugged for a bit UNTIL you can retune - it just won't run very well at all - but should run...eh?
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Old 07-08-2014, 04:38 PM
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I would think the STFT would be going crazy trying to lean it back out. It might be able to learn around it but I guess I'm too chicken to go try it out...
Old 07-08-2014, 04:52 PM
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Originally Posted by JetMech442
I would think the STFT would be going crazy trying to lean it back out. It might be able to learn around it but I guess I'm too chicken to go try it out...
I'm trying to get it to run well enough to charge the ac and get it on and off the trailer to the dyno tuner.

Where a lot of people are putting larger mafs on their car, I'm trying to scale this one back because for all it has in peak hp it has drive ability issues that I believe can go away with the right combo of parts and tuning. Had the 802 green blue PCM on a red blue harness and other modified things.

We can always go back big.
Old 07-23-2014, 11:46 PM
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This is great info! But does anyone have any ideas about what pins need to be swapped in a Calloway 100mm MAF to work in an LS1 harness? We have the LS1 3 pin/2 pin to 5 pin adaptor, but we're throwing a MAF code. Since it's a Corvette MAF, I've read that we need to re-pin the MAF to work with an LS1 camaro harness.



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