Controlling Knock Control

[D-RobIMW]

Have you looked into the adding of any aftermarket parts/tunes that could potentially add background noise, throwing off the knock threshold map, and in turn falsely adding knock control?

When we are talking non-Si ECU's, with stock internal engines, this simply doesn't appear to be the case. Even completely stock cars will consistently raise the knock control value at higher engine speeds, even when total ignition advance is removed by large values (just resulting in a major power loss feedback cycle).

The knock sensitivity tables on Si (5AM) and non-Si (5AA, 5AN, etc) ECU's are IDENTICAL. The knock retard multiplier tables have identical values above 5,500rpm between the files. They have identical knock retard tables. The rise in knock control above 5,200rpm (in the event that there is no significant actual knock sensor activity adding insult to injury) appears to be a background behavior. There are quite a number of tables in the ECU that are still unknown in terms of function, and we are constantly working to test said function.

I hope this sheds a little light on the subject, and I apologize for a miscalculation regarding another shop's downright false dyno number inflation.

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[andyboyd102]

When we are talking non-Si ECU's, with stock internal engines, this simply doesn't appear to be the case. Even completely stock cars will consistently raise the knock control value at higher engine speeds, even when total ignition advance is removed by large values (just resulting in a major power loss feedback cycle).

The knock sensitivity tables on Si (5AM) and non-Si (5AA, 5AN, etc) ECU's are IDENTICAL. The knock retard multiplier tables have identical values above 5,500rpm between the files. They have identical knock retard tables. The rise in knock control above 5,200rpm (in the event that there is no significant actual knock sensor activity adding insult to injury) appears to be a background behavior. There are quite a number of tables in the ECU that are still unknown in terms of function, and we are constantly working to test said function.

I hope this sheds a little light on the subject, and I apologize for a miscalculation regarding another shop's downright false dyno number inflation.

Well said

 

[imcrspy]

I'm sorry you feel this way, @ryanfk7 . The fact remains that I have tuned more of these cars than anyone in the world at this point (there are literally thousands of CivicX/AccordX models using my calibrations, by no stretch of figure).

@imcrspy , as KTuner mentioned, I do have access to knock sensitivity tables, but is the juice worth the squeeze? You have a stock FK7 engine (the least durable of all L15's, it seems), operating at a much-elevated power level. The factory knock sensitivity isn't a bad thing when it comes to keeping the engine alive.

@D-RobIMW oh i'm not arguing with you at all. My car feels fantastic and I can't thank you enough. My concern was if I built my engine i'd still be dealing with the same issues with KC. Thank you for clarifying tho! Makes things a lot more clear for me now knowing you can make adjustments. Gives me incentive to actually build my internals rather than switching platforms. Guess you'll be hearing again from me soon for a re-tune lol.

Anybody questioning DRob should probably listen to someone that's actually dealt with him. He's put in way more effort and time than I was expecting and has been extremely informative with every aspect of my build process. My mistake for not asking him directly. I can't recommend DRob enough if you're looking to tune your car. It's a real shame that some people who have never dealt with him are questioning his abilities and it's a little frustrating as well. If anybody has any questions about my experience with DRob tuning my car, please feel free to DM me. If you're curious at all about getting an e-tune or if you're local to him, I again cannot recommend him enough. Without him i'm pretty sure I would've ended up at a shop that rhymes with perch and blown my engine long ago.

 

[kytos]

I'm sorry you feel this way, @ryanfk7 . The fact remains that I have tuned more of these cars than anyone in the world at this point (there are literally thousands of CivicX/AccordX models using my calibrations, by no stretch of figure).

@imcrspy , as KTuner mentioned, I do have access to knock sensitivity tables, but is the juice worth the squeeze? You have a stock FK7 engine (the least durable of all L15's, it seems), operating at a much-elevated power level. The factory knock sensitivity isn't a bad thing when it comes to keeping the engine alive.

All I can say from the feedback of all spanish (spain) users is we love Derek tunes, being the TSP Stage1 or custom e-tune. Can't be wrong with the most experienced tuner on this platform/engine.

 

[David228cx]

very first person i've ever seen make this sort of comment towards him, when everyone else who has his tune has 0 complaints?

Interesting. Seems biased to be honest, not sure why you would say that here.

All I can say from the feedback of all spanish (spain) users is we love Derek tunes, being the TSP Stage1 or custom e-tune. Can't be wrong with the most experienced tuner on this platform/engine.

You gotta give credit where credit is due. So, to sum things up, those sensitivity values past 5200 rpm could be modified but are left there to protect the engine? Good.

 

[Myx]

Here's a good read on the Honda Civics ECU and how it tries to reduce/prevent knock under certain circumstances.
Benchmarking a 2016 Honda Civic 1.5-liter L15B7 Turbocharged Engine and Evaluating the Future Efciency Potential of Turbocharged Engines
Page 5 in the link states this -->

The ECU avoids these damaging effects by transiently adjusting the engine control parameters, often at the expense of fuel consumption and efficiency, through control techniques such as spark retard and fuel enrichment.

I've seen it before but in the interest of this thread, decided to do some re-reading to get some more insight as to what the ECU is doing during high loads. I have a 2018 base model CVT and after looking through a few datalogs, I'm not seeing this same rise that others have been. The knock control stays at .53 for the most part. On a few occasions, I have seen it move up to the .6* range. I did two datalogs last night and don't recall seeing the knock control go above .53. And this is with the tranny gear in 'L', which keeps the revs at max rpm the whole time at wide open throttle (WOT).

Also, with this problem in mind, I'd advise not going to a louder exhaust than stock. I do recall testing my 2015 Honda Fit LX CVT at the track with a J's racing muffler and noticed my ignition advance was pulled about 3 degrees during wide open throttle. Went back to the same track the next morning and tested again with the same temperature as the night before but with a quieter muffler and my ignition advance was 3 degrees higher. All else being equal, my 1/4 mile times and trap speed was a tick better than the night before but it was consistent. It would've been interesting to have datalogged all the runs and compare the knock control but I was primarily using the Torque Pro app at that time. In a nutshell, run a quieter exhaust to help prevent any false knocks if possible. Or simply keep your exhaust stock'ish'.

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