RomRaider

Yes, very good advice. Sorry I forgot to mention this in my post earlier.

Given that then if my stock map is starting at -10% at 'learning a' and evenly moving to 0% at 'learning d' is this causing damage? Or does the fact that learning d is 0% mean that its unlikely to be an issue because the majority of open loop isn't being adjusted?

I was under the impression thats if it was say -6%, that this meant the ecu had learned to pull 6% of fuel from what it is supposed to be so it can target eg. cl 14.47 ? or have i missed something.
mine currently reads around -2% in range A and about -0.88% at range B.

My impression is that say AFR Learning D is -10%, it will pull 10% enrichment. For example, if the map is calling for 11:1 but AFR Learning D is -10%, then the actual AFR will be 10% leaner than 11:1. I'm not sure exactly how lean than would make it....

14.7 stoich - 11 map = 3.7 enrichment that the map calls for... if Learning D is -10%, then instead of 3.7 enrichment it would be 10% less, or 3.33 so when the map is calling for 11:1 the AFR would be around 11.3:1. I'm not sure if this is the best or most accurate way to think about it, but at any rate if Learning D is substantially negative then AFR's will be leaner than the map calls for (what the map was tuned for).

Please correct me if I'm wrong.... thanks.

I believe you have overthought it. AFAIK:

11.0 x 1.10 = ~12.1 AFR

(Also showing conversion to lambda and back)

11.0 / 14.7 = ~.748 * 1.10 = .8228 * 14.7 = ~12.1 AFR

I don't think that's the way the primary fuel tables work. I think it is basically an "enrichment vs. stoich" table and only presented in Romraider in terms of AFR for ease of use. You are suggesting the fueling table is a reference from zero fuel.

AF Correction is not based on enrichment AFAIK. It is based on total fueling error from "zero" (targeted CL AFR, usually ~14.7). Please prove me wrong.

EDIT: It would simply not make sense for AF Correct/Learning to be applied to enrichment. This would render it useless during most CL operation.

The question at hand is... "If AFR Learning D is -10%, what would be the actual AFR at WOT in open loop for a map that calls for and was tuned at 11:1"

I say ~11.3:1, you say ~12.1:1. We are quite a ways off. I'll wait for a pro like merchgod or mickey for a more definitive answer.

What you are saying is that AF Learning is applied to only to enrichment during OL operation but is applied to absolute fueling during CL operation. Please explain the logic behind MAF range "D" that would require a 10% absolute reduction during CL operation but only a 10% enrichment reduction during OL operation. Think about it

thanks for your reply but surely if the the LTFT have settled and its showing -10% in the D range then surely the ecu has learned that it needs to pull fuel in that area to reach its target so it will not go lean or even rich.
or is this totally wrong because it applies the -10% across the whole fuel range.

That's assuming the MAF was scaled correctly.

I think what Guy on the Corner is saying is that we don't know what happens to the WOT region.

AFR Learning D on the LGT is set by the MAF range between 40 and 65 (approx.) g/s range. Once AFR Learning D is set, it affects the entire MAF range above 40 g/s.

If the entire MAF scale was scaled correctly then as AFRLD changes, it changes the entire scale correctly.

However, the SPT intake has a funky MAF scale. THe MAF sensor is embedded right in the S bend of the pipe.

Most tuners when they tune an intake will tune the WOT range with AFRLD=0. This is because the value is reset to 0 after every flash. There are some tuners who will set the AFRLD correctly by doing a fast cruise etc... but most don't.

Personally, I tune the closed loop range first. I try to get AFRLD to be within +-2% and AFRLA,B, and C to be withing +-5%. After that I scale the WOT region.

Unless I am mistaken, what he believes is that AF Learning is applied to the ENRICHMENT factor being applied during OL operation and not to ABSOLUTE fueling. Not sure what he thinks is supposed to happen during CL operation with regards to AF Learning being applied

Please correct or confirm these statements...

A) I believe the AFR Learning D correction is applied to OL. Specifically, I am thinking about WOT.

B) I believe this percentage correction (AFR Learning D) applies to primary fueling.

C) I believe that the primary fuel table itself is an enrichment table versus stoich.

I'm not thinking about CL now, other than AFR Learning D.

A/F correction and learning are simply two additional correction factors to fueling. The primary fuel map is another (actually an enrichment offset to the primary fuel multiplier). The ECU does not use two different strategies for calculating IPW for closed loop and open loop. Rather, the difference in fueling is determined by the correction factors. So, in closed loop, the primary fueling multiplier would always be 1.0, and in open loop, A/F correction multiplier would always be 1.0.

Simplified:
IPW for stoich fueling at current load * Primary Fuel Multiplier * A/F correction #1 multiplier * A/F Learning #1 multiplier * all other correction factors

So, it doesn't matter what A/F learning range you are in, it will be applied to the fueling regardless.