Question regarding Powerlogger, knock and timing

[Pronto]

I've been wondering about this for a while so here's my question. When logging with the Powerlogger at WOT, if you encounter a knock spike, will you see a corresponding lowering of the spark advance on the graph or will the graph show what the timing is set for at WOT. This is with a TT6.1 chip.

 

[TurboBob]

on the powerlogger (and all scantools and loggers for the Buick) the knock retard amount is not reflected in the total timing value displayed.

This applies to all chips you might run, its an artifact of the way spark advance factors are applied to the timing calculation in the Delco software in the ECM.

Bob

 

[Pronto]

So then you really can't tell how much timing might be pulled for a given knock retard number?

 

[Eric Stage I]

That's what knock retard is. The amount that timing is retarded.

 

[Pronto]

OK, now I see. In the data screen there is a field for knock counts. Can you explain what knock counts mean?

 

[Pronto]

Doing my homework searching. Found interesting info. I don't understand alot of it but some of it is getting though.

 

[Eric Stage I]

I'll try to do the short version...
The ESC module sends a signal to the ECM when knock is detected. This signal is time based, so the more intense the knock is, the longer the signal lasts. The knock counter counts upward based on how long the signal lasted. The ECM takes that counter info and calculates how much timing to retard.

I typically ignore the knock counter and only look at knock retard.

Eric

 

[Pronto]

Last questions. Can the way the log of the knock retard and counts looks or tracks help determine if the knock is detonation or other noise? Is there a point of retard that audible knock can be heard?

Since we have the ability to log these events which we never had, I've been trying to understand relationships between all the info we can see now. Thanks for helping.