M130 pulling timing/knock

I'm tuning a 3 cylinder UTV with a M130 that's odd. I am getting the knock warning even when the knock noise is below the threshold and can see it pull some timing on the #2 cylinder at the same time. It is close to the threshold, will the ecu anticipate it crossing the threshold? It's a very specific setup and I'm not able to see knock A-B-C-D noise I can only see knock level % on 1-2-3. The gains are %/v is lower on the #2 making me think it's a noisier cylinder. It's set to 160% on #2. I've pulled a ton of timing and ran it on the lowest boost possible and the noise looks the same. Should I just continue to raise the threshold or maybe lower the gain numbers?

I would recommend starting off by watching the webinar on this:

https://www.hpacademy.com/previous-webinars/motec-m1-knock-control-example/

If you are only working in tune, and do not have level 2 logging to allow you to check the levels on each channel, modify your time graph in M1 Tune to suit the application. Right click on the "Layout" tab on the left side of the screen, right click the workbook and select unlock.

I would recommend having a section with each channel for each cylinder and the threshold in its own section. This allows you to check which has the best signal to noise ratio on an actual knock event. A bit of time needs to be spent grouping the frequencies around the frequency, or second order frequency that the knock sensor detects best.

You will want a little bit of head room in your threshold (when properly tuned) to allow for spikes in the knock level detection on transients, where knock isn't taking place, but the rapid increase in cylinder pressure causes the detected knock level to increase. Everything should also be confirmed with audio knock equipment, you will not be able to effectively set up knock control in 90% of systems without audio knock detection assistance.

The knock warning system is separate to the knock control. This allows you to set a knock level, or an amount of knock timing retard that triggers the warning state to be knock warning. This allows you to set an in M1Tune alarm or visual aid via the warning state gauge if your in a different work sheet (such as the fuel tuning worksheet) that the knock levels have reached your predetermined warning level, so you should probably take a look at them.

The Knock level channel will show the highest value of and of the active A, B, C or D channels at any point in time.

I don't think I have ever had a combination where my gains have been identical between all the cylinders (Particularly if the knock sensor is wired as a differential sensor), you need to check at a point of high cylinder pressure without knock events that the knock levels are roughly reading the same level, as the cylinders closest to the sensor will naturally read higher.

I watched that video and others a few times. Right clicking on the work book to unlock them is the trick I needed to proceed. Thank you!!

Here's a pic of what I was thinking was a issue. I'll follow the vid and redo knock setup soon

Hi Connor,

The knock channels are displayed in the time graphs at 50hz but the Knock system is running at 200hz for the update events (screen, warnings) and higher for the control system. It is possible for a knock event to occur and be acted on, but not displayed on the screen as it has occurred between the screen updates. If you logged the data at a faster rate you would most likely capture these events occurring.

Thank you!! I really appreciate the quick reply’s!