fine knock learning

[johnmkv]

Ive recently started watching my fine knock learning in real time and have notice some values from time to time they range from .1 to +/-2.5 highest

This happens under normal driving conditions once in a while and under accelerating and boost more often im gettin pro-tuned in a few days but i would just like to know what are the possible reasons for that

2012 wrx cobb ap stg2
Nameless performance TBE
Turbosmart 50/50 bov

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[bshep211]

Originally Posted by johnmkv

Ive recently started watching my fine knock learning in real time and have notice some values from time to time they range from .1 to +/-2.5 highest

This happens under normal driving conditions once in a while and under accelerating and boost more often im gettin pro-tuned in a few days but i would just like to know what are the possible reasons for that

2012 wrx cobb ap stg2
Nameless performance TBE
Turbosmart 50/50 bov

Cobb documentation says 2 -\+ is normal. If you start getting -4 knock and lower DAM then you may have a issue.

[Cobb Tuning]

Originally Posted by johnmkv

Ive recently started watching my fine knock learning in real time and have notice some values from time to time they range from .1 to +/-2.5 highest

This happens under normal driving conditions once in a while and under accelerating and boost more often im gettin pro-tuned in a few days but i would just like to know what are the possible reasons for that

2012 wrx cobb ap stg2
Nameless performance TBE
Turbosmart 50/50 bov

You will have the occasional feedback knock correction and fine knock learning, especially at low loads, and this is generally noise. When you see extreme values or consistent correction in the middle of a WOT run (not due to mashing the throttle at the start of the run or lifting abruptly at the end of the run), then that is more of a concern.

Bill

[johnmkv]

Thanks for the input at least i wont worry too much before the tune

[johnmkv]

Alright so i just did a data log 3rd gear and im noticing 3 separate times where fine knock is initiated up to 1.4 +/- then learned away within a few rows

https://docs.google.com/spreadsheet/...ISjRhRmc#gid=0

Is it possible that the turbo smart hybrid bov is leaking and causing this knock?

[Cobb Tuning]

Originally Posted by johnmkv

Alright so i just did a data log 3rd gear and im noticing 3 separate times where fine knock is initiated up to 1.4 +/- then learned away within a few rows

https://docs.google.com/spreadsheet/...ISjRhRmc#gid=0

Is it possible that the turbo smart hybrid bov is leaking and causing this knock?

I would go ahead and reflash our most conservative map (91ACN). The fine knock learning can sometimes be noise due to lifting off the throttle abruptly at the end of a WOT run, but you do have some multiple counts multiple times, which is a bit unusual. Leaks are certainly a possibility. Your long-term fuel trims (A/F Learning 1) look OK, but you may have not have driven long enough for them to populate accurately (since the AccessPORT install, map reflash or ECU reset). Try driving through a tank of gas after reflashing the 91ACN map and see where they sit (you can view the individual A/F Learning 1 ranges via the A/F Learning 1 A,B,C,D parameters).

Bill