lrx automotive Posted March 21, 2022 Report Share Posted March 21, 2022 Hi, I'm new here, I realize my map and I have a knock trim problem with my G4X link on my mini r53. (rotrex supercharger) I sometimes have -3 degrees of knock trim, but my knock threshold limit is not exceeded... I also have more knock level on my cylinder 1 and 4. I deactivated the knock trim on its 2 cylinder to get even further away from my knock threshold limit to do a test, but no change. I also tested by decreasing my lead to 14° instead of 23°, but still knock trim, (at 14° the noise is the same) here is a log and my map, with 3 accelerations we can see that there is no knock trim on the 1st run, and then it happens on the other 2 accelerations. can someone help me? ( sory for my bad english ... ) thanks, nico LINK NICO TEST 2 OK 2.4 NEW KNOCK.pclx LOG 1 2.4.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 21, 2022 Report Share Posted March 21, 2022 You can see after you lifted off at the end of the first pull that your knock level went above the threshold from about 6250 to 5700RPM. This has resulted in a knock trim being applied between these RPM's. The knock trim gets written into the knock trim table so that when the engine next passes through this same RPM band it gets the same knock trim applied (whether it is knocking or not). Only after the engine has been operating in that RPM band for some time (Ign advance delay) without knock, then the ecu will start slowly removing the knock trim (ign advance rate). So a couple of things you could do to fix: Increase threshold in the high RPM/low MAP cells that it passes through after you lift off. I have highlighted the cells in the table below that are causing the problem. Add MAP or TP to the Y axis of the knock trim table so that the trim doesnt get applied to the same RPM regardless of load. lrx automotive 1 Quote Link to comment Share on other sites More sharing options...
lrx automotive Posted March 21, 2022 Author Report Share Posted March 21, 2022 Thanks very much ! I will test it as soon as possible, I will post the result here. is the equivalent of the adaptive values? I have been looking for my problem for 10 days, and you solve it in 20 minutes Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 21, 2022 Report Share Posted March 21, 2022 After that first run since there was knock detected at ~5500-6500, the knock trim table would have looked something like this: So the next time the engine passes through 5500-6500 this same trim would be applied. These values in this table will stay there until the engine has been operating in the same cell again with no knock detected, then it will start removing the retard. These tables are cleared back to zero also everytime the ecu is powered up. Whereas if the knock trim table had MAP on the Y axis, then only something like these 4 cells would be trimmed (below). This means you would only get retard in low load areas where it wouldnt affect performance. But still it would be better to fix the threshold so that it is not falsely detecting knock in the first place... Quote Link to comment Share on other sites More sharing options...
lrx automotive Posted March 21, 2022 Author Report Share Posted March 21, 2022 thank you for taking the time to explain the problem to me. Quote Link to comment Share on other sites More sharing options...
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