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Having trouble identifying knock

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Hey guys,

I've been out street tuning my fuel map, datalogging and going through each rpm load zone, then pulling over and making adjustments. I'm using audio knock detection headphones as I drive, and I am using the wrx base ignition map from the link g4+ for my ignition timing settings, retarding each rpm column by 5% before drive through that rpm column. I'm logging my knock levels as I do this, and I have set a knock threshold for each rpm. As I was tuning my 4500rpm zone I noticed a higher amount of knock noise from cylinders 3/4. I couldn't hear knock through my headset, however I am not confident in differentiating knock, as I don't believe ive ever heard it on my car. Ive attached the datalog from the run, and what puzzled me was that the higher noise from cylinders 3/4 begins at very light throttle (40kpa), which leads me to believe it's not knocking. Would this be a matter of reducing cylinder 3/4's gain?

Also, any tips in how to purposely induce knock on the my engine (ej205) so that I can learn to differentiate between that and engine noise? I tried greatly increasing the timing in a few different cells (38/40 degrees at 2500rpm 100kpa for example) but i couldnt hear anything and no spikes in the datalog to show knocking. Do these engines require a greater load/ rpm before they knock?

Thanks for your help, so many questions I know, I'm just a rookie ;)

Attached Files


there is no Ignition angle in your screen shot.

Also you should log knock in ECU logger at 100Hz minimum.

I would also suggest to "zoom" Lambda target/lambda to at least 1 to 0.75

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