Connected up knock. Any advice on settings?

[[email protected]]

Today I configured the knock in my Link ecu. One of my valve clearances is a little large and I guess that is why cylinder 3 was so high. I turned the gain down on cyl 3 to 0.20 and the gain down on cylinder 2 to 0.50 as it was also way out of scale to the other cylinders. Can you have a look if I am on the right track and adjust anything that could help me. I have included two log files. The one labeled 2nd run is before I adjusted anything. The 2nd is labeled 12th run, this is after I adjusted the gains and tried moving the target. Any advice would be appreciated.

The sensor is a two wire donut style unit off a late model Toyota Vitz/Echo. My Ecu is a G4+ Storm Blue. The engine is a 3sge beams 5th gen with ITB throttles and a shared vacuum chamber going to the map inside the Link. I am using the internal knock within the Link ecu. 

Files included are: Two log files. The Tune file. A screen shot of the knock level.

https://drive.google.com/drive/folders/18Ed9hvKGfWZL9nwguWrHkTRzu4CaDcvB?usp=sharing

I am really enjoying the link. Thanks Rex in Inglewood Taranaki.

[Adamw]

Doesnt really look like it is working well yet.  I would change the freq channel to 6khz narrow, drop the gain channel to about 2 or 3, change the window start to 30 and see if that looks any better and the cylinders balance better.  It is normal for the cylinders that are closer to the sensor to need less gain but your variation from cyl to cyl looks excessive

[KarlSzz]

On 8/27/2021 at 3:13 PM, Adamw said:

Doesnt really look like it is working well yet.  I would change the freq channel to 6khz narrow, drop the gain channel to about 2 or 3, change the window start to 30 and see if that looks any better and the cylinders balance better.  It is normal for the cylinders that are closer to the sensor to need less gain but your variation from cyl to cyl looks excessive

Hi adam, I am curious about the freq channel you mentioned. I found my knock frequency to be at 7.5kHz. I'm not sure whether to set the freq channel to 7kHz or 8kHz, as i am not sure what is the listening frequency of each selection. For example does 7kHz selection listens to 6.5-7.5kHz or 7-8kHz? Thanks

[Adamw]

The frequency setting is the center frequency, I dont know how steep the roll off each side of that is but obviously the further you go from the set center frequency the less will get through.

My recommendation of 6Khz above is just from my experience with the 3SGE.  The frequency of every engine is different and it can even be influenced significantly by the chassis and other accessories attached to the engine.  The bore size based calculations are better than nothing, but not always relevant, the real aim is to find the frequency with the best signal to noise ratio rather than just the most noise.