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Anyone experienced this or ideas as to what's going on?

Between 3000 and 3600 RPM, STFTs go way positive and AFR goes lean, I've seen up into the 14.xx range. I didn't log commanded AFR in the log below, but if you do it's very evident that the AFR balloons in that RPM band, then goes back to normal.

I also noticed in the same band that air flow mass dips or stagnates. Maybe this is the root cause-- air flow calc is off here and as a result not enough fuel is injected and the STFTs aren't really able to compensate fast enough.

Also right at 3300 RPM I noticed ignition timing takes an instant dive to 13.x# to around 6*.

If I start a pull at 3k rpm or higher, it does this a little bit, but not nearly as pronounced as when I start it at a low 2500 RPM.

Seems to be a number of odd things going on and just wanted to hear your guys' thoughts, experiences, ideas.

Thanks!

datazap.me | aaronc7 | BTFT v100 Datalogs
 

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My biggest question is why are you asking on a forum and not discussing with your tuner?

You answered you own question on fueling. The requested AFR should not balloon, if anything, the requested AFR should drop as rpm increases to as low as 11:1 to safeguard and keep things cool.

The timing changes are logical: Timing is likely being pulled to save the motor. Known lean condition + RPMs = DANGER WILL ROBINSON, and the ECU is trying to save the hardware.
 

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I've seen something similar on all my logs too with 3 different tuners. I think it's relatively normal I believe. I think it just takes a second or so for the hpfp (or lpfp?) to catch up because boost comes in so quick.

Would be great for a tuner to chime in tho.



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