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Normalised knock


SimonSTI

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Is there some documentation on that new feature with some guideline on how to set it up?

I've read the updated help file and look at all the table, but still not 100% clear to me how to set it up properly.

Do you have to setup the knock threshold table when using this mode?

 

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I've helped with development of the new knock normalised mode and done lots of Beta testing. 

The Knock Normalised Mode has the big benefit that it will adapt to increased noise level, when your engine wear over time and consequently produce more background noise. In tradional mode this will lead to false knock detection. In general speaking Knock Normalised mode will  adapt to changing background noise levels and should need less adjustment from engine to engine, once you have a good basemap worked out. It also allows better adjustment how much ignition retard is applied, based on knock level detected. 

It is meant to use all the tables, which are shown in PC LINK in this mode.

I would start with a small Knock Target Table. Break points every 1000rpm and on y-axis every 50kpa (boosted engine) should be sufficient. A filled table of 2.0 should be a good to starting point.

During transient engine operation the knock levels are going higher. In the tradional mode lockouts for delta rpm and tps where set. In Knock Normalised Mode it is meant to use all the Knock Transient Tables to keep knock control active all the time. The Knock Normalised Levels will increase even more, during transient operation, than in traditional mode. The idea with all the transient threshold tables is to increase temporarly the knock treshold, instead of just deactivating knock control. 

As a starting point fill the Knock Normalised MAP and RPM Delta Level tables with factor 1.5. 

The Knock Normalised Delta RPM and RPM threshold defines when the knock multiplicator above is applied. Setting is very dependand how stable your knock engine speed ROC and knock Map Delta channels are. If there are too noisy you can apply more filter to get this channel(s) smoothed. 

I recommend the following order for setup and tuning. 

1. setup function as suggested above

2. adjust knock noise filter (same process as in tradional mode)

3. calibrate knock target table in steady state conditions

4. calibrate all knock transient tables, so knock target is little above knock levels in all knock free transient condions. 

Notes: 

- you can calibrate knock input filter also in tradional knock mode. This setting will be the same in both modes. 

- it is normal behavior that knock normalised levels go higher during transient than in steady state operation

- as always when you calibrate knock detection system use knock ears! 

- Important knock level detected must be logged with internal logger with at least 200hz (better more) to show peak values correct in PC Link

 

 

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  • 1 month later...
On 12/5/2020 at 3:21 PM, mapper said:

I've helped with development of the new knock normalised mode and done lots of Beta testing. 

The Knock Normalised Mode has the big benefit that it will adapt to increased noise level, when your engine wear over time and consequently produce more background noise. In tradional mode this will lead to false knock detection. In general speaking Knock Normalised mode will  adapt to changing background noise levels and should need less adjustment from engine to engine, once you have a good basemap worked out. It also allows better adjustment how much ignition retard is applied, based on knock level detected. 

It is meant to use all the tables, which are shown in PC LINK in this mode.

I would start with a small Knock Target Table. Break points every 1000rpm and on y-axis every 50kpa (boosted engine) should be sufficient. A filled table of 2.0 should be a good to starting point.

During transient engine operation the knock levels are going higher. In the tradional mode lockouts for delta rpm and tps where set. In Knock Normalised Mode it is meant to use all the Knock Transient Tables to keep knock control active all the time. The Knock Normalised Levels will increase even more, during transient operation, than in traditional mode. The idea with all the transient threshold tables is to increase temporarly the knock treshold, instead of just deactivating knock control. 

As a starting point fill the Knock Normalised MAP and RPM Delta Level tables with factor 1.5. 

The Knock Normalised Delta RPM and RPM threshold defines when the knock multiplicator above is applied. Setting is very dependand how stable your knock engine speed ROC and knock Map Delta channels are. If there are too noisy you can apply more filter to get this channel(s) smoothed. 

I recommend the following order for setup and tuning. 

1. setup function as suggested above

2. adjust knock noise filter (same process as in tradional mode)

3. calibrate knock target table in steady state conditions

4. calibrate all knock transient tables, so knock target is little above knock levels in all knock free transient condions. 

Notes: 

- you can calibrate knock input filter also in tradional knock mode. This setting will be the same in both modes. 

- it is normal behavior that knock normalised levels go higher during transient than in steady state operation

- as always when you calibrate knock detection system use knock ears! 

- Important knock level detected must be logged with internal logger with at least 200hz (better more) to show peak values correct in PC Link

 

 

Thank you for this explanation, today Yesterday I have make a log with my lancer evo ix, with your guide, but now....I have a hard time interpreting it..

 

image.thumb.png.4b15205514f1411640cf4240b29688dd.png

I don´t know if I have well configured:

image.thumb.png.a350d198319b527483ce1a41d2d09f9d.png

 

PC Datalog - 2021-01-29 7;42;05 pm.llgx

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I havent looked at your log, but it doesnt look like you are too far off.  Your noise looks a little more erratic than Im used to, whats your frequency channel and start/window set to?  Does your engine still have the stock 2 tooth crank wheel?

Your noise levels increase quite a bit during transients so your delta threshold gains need to be a bit higher (so the threshold steps up higher during transients).  It also looks like your normal threshold may need to come up to about 2.5 to get it above the odd bit spike of noise you have.

 

 

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On 1/31/2021 at 10:12 AM, Adamw said:

I havent looked at your log, but it doesnt look like you are too far off.  Your noise looks a little more erratic than Im used to, whats your frequency channel and start/window set to?  Does your engine still have the stock 2 tooth crank wheel?

Your noise levels increase quite a bit during transients so your delta threshold gains need to be a bit higher (so the threshold steps up higher during transients).  It also looks like your normal threshold may need to come up to about 2.5 to get it above the odd bit spike of noise you have.

 

Thank you Adam for your time!

I have OEM tooth crank wheel, and i have upgrade the knock sensor for a Bosch sensor. I will modify the threshold gains for the following log´s.

My configuration is the following (now)

image.png.b4a1bce43123200cd4f018591a29e5cb.png

 

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Yeah, I was going to suggest you try setting learning rates to fast too.  I havent tried normalised knock mode with a low tooth count trigger wheel. 

Also, I would try 13KHz narrow and 20deg window start, 50 deg length. - At least these values work best on my evo (not using normalised knock however as I last tuned it before that option was available). 

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11 hours ago, Adamw said:

Yeah, I was going to suggest you try setting learning rates to fast too.  I havent tried normalised knock mode with a low tooth count trigger wheel. 

Also, I would try 13KHz narrow and 20deg window start, 50 deg length. - At least these values work best on my evo (not using normalised knock however as I last tuned it before that option was available). 

Ok Adam, I will go faster and adjust this window´s parameters.,

 

I have a due, I have installed an aftermaket bosch sensor in my 4G63, and for this reason I go to 6Khz (I have rebuild with 86mm of piston), 6.5Khz..more o less if I take the phormula.

Do you think that is better 13khz with this sensor too?

 

Thank you.

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  • 3 weeks later...

Yes all our G4X ecu's with knock control have normalised knock mode. 

PC link will only show the features that are available in the firmware of the ecu you are connected to or in the map you are viewing if viewing offline.  

If you have the latest firmware in your ecu and have PC link connected then you will see normalised knock mode.  

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12 minutes ago, Oldmanz350 said:

Firmware is V6.18.11, it says up to date.

Current release is 6.19.105, you need to download and install a new PCLink from the website and install the firmware that comes with it.

https://linkecu.com/software-support/pc-link-downloads/

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17 minutes ago, Oldmanz350 said:

What would you guys recommend for settings on a 350Z PnP?

This is what I have on my 2GR (3.5L Naturally  aspirated v6) MR2, I did play around with it quite a bit so unsure how optimal this setup is but it should be a good starting point.

Capture.PNG

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  • 1 month later...

Sharing my first result and asking a few questions on this feature.

To give a bit of context car is a Subaru STI 2.35 engine, high compression 9.5:1, session done on pump 94 octane + 1 can of octane booster. Car was running super rich as I'm adjusting fueling after a lambda sensor swap.

I used the recommended features in this thread as a starting point. (knock threshold at 2.0)

Looks like cylinder 4 is knocking between 5000 and 6000 rpm quite often and cylinder 2 once in while. Between 2.5 and 3.0. Dash knock lite (turbo XS model) is not showing knock or I didn't notice, but I usually see it. My guess is that it's moderate knock event considering timing, rpm and fuel.

Can someone confirm based on their experience if these knock level are moderate or high?

Here is one example:

PCLink_DdPDPw2SAo.png.8b062515ef69731dff6ae42477976787.png

 

Second question, on this track we use second gear in a slow corner. I get a RPM rate of around 1300 rpm per sec. in this corner. 3rd gear is more around 800 rpm per sec. What RPM delta should I target? Between 2 and 3 gear acceleration at around 1000 rpm or should I go higher to include 2nd gear like 1500?

 

link to my map and log file: https://1drv.ms/u/s!AlShENwUdCOZgqxjBJqtFBGtWua5wA?e=dOyoX7

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I had a quick look over your log.  I agree it definately looks like there is some mild knock in the 5000-6000rpm region on at least a couple of cylinders.  The easiest test is generally to pull 5deg out of the cells around that area and if the noise levels flatten out then it is a strong suggestion it is knock.  

The delta threshold is getting tripped more often than it should be and in some places it looks like it is not getting tripped when it needs to be so I think the deltas still need a bit of work.    Add these channels to you log will help see what is going on. 

i7OarKA.png

 

I will attach some example settings from our 2.0 JDM V11 STI.  Im not sure how relevent they will be but it might give you a feel for the trends.  There are definately some of these settings I havent experimented with much and probably need more optimising one day but the knock control in this car works well and can be relied on as is.  It is a bit erractic at around 2000RPM no matter what I do which is why I have it disabled below 2500. 

I only use ign trim as fuel doesnt seem to do much to supress knock in piston engines, it works well in rotaries though which is the main reason it is there as an option.

Sbxqau3.png

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