Different AFR´s in different Gears?

[Treurentner]

Hi,

I putted a powerdyne with fmu on my GMC Jimmy with L35 Vortec engine.
Now my techedge (1.0) wideband shows different AFR´s in different gears at same rpm´s - generally the higer the gear the richer the mixture.
What causes this?
Its independend from VE or maf tuning,
1. Gear 12,5:1,
2. Gear 12:1,
3. Gear 11,5:1
4. Gear 11:1,
in every case the car is in open loop and PE is active. The commanded AFR and the reall live are nort far off. But what causes an commanded AFR fom 11.1 :1 wenn I floor the throttle and when I lift off only a little (still in PE and OL) it´s going back to 12.5?
I append an example with basic stock tuning. You will see that in the same moment the mV fom stock O2 sensors went slightly down (leaner), the afr from Wideband shows going richer. I ensure that CL is working perfect, and wideband shows exactly 14.7!
How can I interpret this - wich data I can belive?
Every recommendation is welcome!

Marco

(the Te wideband 1.0 is non linear and so this is the transfer table:
Vout Lambda Petrol
1.40 0.686 10.08
1.45 0.696 10.23
1.50 0.706 10.38
1.55 0.716 10.53
1.60 0.727 10.69
1.65 0.739 10.86
1.70 0.750 11.03
1.75 0.762 11.20
1.80 0.774 11.38
1.85 0.787 11.57
1.90 0.800 11.76
1.95 0.814 11.96
2.00 0.828 12.17
2.05 0.842 12.38
2.10 0.857 12.60
2.15 0.873 12.83
2.20 0.889 13.07
2.25 0.905 13.31
2.30 0.923 13.57
2.35 0.941 13.84
2.40 0.960 14.11
2.45 0.980 14.40
2.50 1.000 14.70

[Delco]

cat convertor enrichment can be envoked under these conditions

[caver]

Its very simple.

In the lower gears the engine accerates very quickly. The ecu is reading tables as fast as it can but it is always playing catchup and lags behind .
Additionally the fuel pump has a harder time because of the g forces involved.

Some makes of cars are worse than others but they all do it.

[dirt_track_racer_81]

I've got the same problem on my truck 1st gear is 12.8 2nd gear is a 12.0 and 3rd gear is 11.0.
Would it be nesessary to lean it out to were its about 13.5 or so in first and maybe it would be leaner in 2nd and 3rd? I'm guessing there's really know way around this?

[caver]

Compromise is the only way. 11:1 is way to rich anyway. Blown should'nt need richer than 11.5:1 if the KR will allow it try closer to 12:1Set it slightly rich in top so that the lower gears are still safe.
The time spent accelerating in the lower gears is minimal compared to a top end run so it cxan cope with being a smidge lean .

[foff667]

also in lower gears there not that much of a load put on the engine compared to 3rd & 4th gear which(at least at the dragstrip) you'll spend most of your time anyways. I wish i could view your log...like mentioned it is also a strong possibility its COT kicking in. Is there a way to log all the multipliers affecting the afr with efilive?

[caver]

Disable cat protection and see what happens.