E38 maff and co efficients tuning

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Mar 10, 2015 | 04:55 AM

Jacktuner

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E38 maff and co efficients tuning

Hi, when tuning e38/e67 pcm's using 2.24 version of hptuners the maf can be tuned but the prediction coefficient's cant be tuned, my question is if the maf can be tuned and the coeffients cant be, wouldnt the engine be running lean in non steady state depending on mods of course? my understanding is the maf is used for steady state and the coefficients are used for quick throttle transitions?

Or once the maf is tuned the coefficients dont matter?
Or just tuning the maf only a cheap way to do it?

TIA......

Mar 16, 2015 | 12:48 PM

Jacktuner

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Surely someone must know?

Mar 16, 2015 | 12:54 PM

RedHardSupra

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From: Laurel, MD

The 'MAF for steady/SD for transitions' logic is from the old ECU's. Not sure if it's still the case with the newer ones.

If you're going to tune only one air estimator, then you do not want to have the other component active at all, as it will most likely feeding your wrong information. Use what's tuned.

Mar 16, 2015 | 03:13 PM

Jacktuner

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Thank you redhardsupra, i guess all the tunes i see that dont have the co efficients disabled must be running lean to some degree, upto 4000rpm when the maf takes over

Mar 16, 2015 | 03:21 PM

RedHardSupra

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From: Laurel, MD

Not necessarily lean, just wrong, might be rich too.
And remember a lot of people that want to run pure MAF change the changeover point (i forget the name of the field) from hybrid to MAF to something very low like 400RPM, so this way it's always ignoring SD.