fed up with knock control
Nov 3, 2008, 04:47 PM
#196
mrfred, that completely blows that the knock sensor is adaptive. So you tune the car by flashing a bunch, but each time you do on a 9 you reset it. Then the ecu adapts and "learns" over time.
Are you sure the "learning" process in the FSM isn't the "learning" of the octane IE: the octane number and low octane maps?
Are you sure the "learning" process in the FSM isn't the "learning" of the octane IE: the octane number and low octane maps?
The guys that created DSMLink have completely diassembled the DSM ECU long before we began messing with the EVO ECU and a lot of it is the same, from what we have learned so far.
So, if the knock algorithm is adaptive in the DSM ECU, then it would only make sense that it is in the Evo as well.
Eric
Nov 5, 2008, 01:53 PM
#198
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Others have already noticed this, but I noticed it BIG TIME yesteday while working on the accel enrich maps in the hunt for its effect on timing control.....
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.
I know on my own rom that I am quickly running out of maps that could be true knock filters. Of the eleven that were initially labelled as filters when I first got into this, seven of them I found to be nothing at all to do with knock (EGR and Purge control most of them) and one extra 3D map I found hidden in there. Two of the remaining 3D maps are all the same number, so most likely not a mapped filter, and the other three are all that are left. Playing with these maps has no effect at all on the knock control. There are no more 3D maps left to be discovered, the rest are only 2D, so I am at the point now where I suspect all of the filtering is 2D or even 1D based.
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.
I know on my own rom that I am quickly running out of maps that could be true knock filters. Of the eleven that were initially labelled as filters when I first got into this, seven of them I found to be nothing at all to do with knock (EGR and Purge control most of them) and one extra 3D map I found hidden in there. Two of the remaining 3D maps are all the same number, so most likely not a mapped filter, and the other three are all that are left. Playing with these maps has no effect at all on the knock control. There are no more 3D maps left to be discovered, the rest are only 2D, so I am at the point now where I suspect all of the filtering is 2D or even 1D based.
Nov 5, 2008, 10:12 PM
#200
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I never used to think that, but after what I was seeing yesterday I am beginning to think about it. The thing that stops me believing it is that the timing I was running at part throttle where I was seeing the knock was still more advanced than what I have at WOT. It wasnt like I was running crazy numbers. I just tagged the entire ignition maps (all 4 of them on my rom) at 15 degrees, and then again tested it at 8 degrees. All ignition trims were zeroed (EGR, In gear advance, Air temp, etc). It is a systematic way of looking for something that causes ignition timing to vary from the values in the main maps. On 8 degrees I could barely see any positive pressure and it would jump immediately to 36 knock. I even zeroed the EGR duty maps to ensure no issues with instable combustion. The motor ran smooth but just retarded itself stupid with the knock control, to the point of antilag.
Unless there is a range in which it looks at that is mapped somewhere, but like I was saying there is almost no 3D tables left for it to exist in. For now, I run a little more advance (couple of degrees) than normal between 90 and 140 load and it runs with virtually no knock sum at all. There is no audible knock either and the knock control doesnt pick it up. I tell you one thing, I trust my ears more than the ecu at this stage. I have also in the past picked up audible knock that showed as only 2 knock sum at WOT. So until we figure this out, the ear is god.
Unless there is a range in which it looks at that is mapped somewhere, but like I was saying there is almost no 3D tables left for it to exist in. For now, I run a little more advance (couple of degrees) than normal between 90 and 140 load and it runs with virtually no knock sum at all. There is no audible knock either and the knock control doesnt pick it up. I tell you one thing, I trust my ears more than the ecu at this stage. I have also in the past picked up audible knock that showed as only 2 knock sum at WOT. So until we figure this out, the ear is god.
Nov 6, 2008, 07:37 AM
#201
Others have already noticed this, but I noticed it BIG TIME yesteday while working on the accel enrich maps in the hunt for its effect on timing control.....
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.
I know on my own rom that I am quickly running out of maps that could be true knock filters. Of the eleven that were initially labelled as filters when I first got into this, seven of them I found to be nothing at all to do with knock (EGR and Purge control most of them) and one extra 3D map I found hidden in there. Two of the remaining 3D maps are all the same number, so most likely not a mapped filter, and the other three are all that are left. Playing with these maps has no effect at all on the knock control. There are no more 3D maps left to be discovered, the rest are only 2D, so I am at the point now where I suspect all of the filtering is 2D or even 1D based.
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.
I know on my own rom that I am quickly running out of maps that could be true knock filters. Of the eleven that were initially labelled as filters when I first got into this, seven of them I found to be nothing at all to do with knock (EGR and Purge control most of them) and one extra 3D map I found hidden in there. Two of the remaining 3D maps are all the same number, so most likely not a mapped filter, and the other three are all that are left. Playing with these maps has no effect at all on the knock control. There are no more 3D maps left to be discovered, the rest are only 2D, so I am at the point now where I suspect all of the filtering is 2D or even 1D based.
Nov 6, 2008, 08:38 AM
#202
[QUOTE=Mattjin;6317030]Others have already noticed this, but I noticed it BIG TIME yesteday while working on the accel enrich maps in the hunt for its effect on timing control.....
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.[QUOTE]
You know what I noticed this as well but dismissed it as being something else. I changed a lot of setting while also increasing the timing in this range. I turned up all the timing in the lower ranges so I could have a little more power while cruising and noticed the knock count did go down but is still there.
Having timing too retarded makes the knock sum go crazy.
Try it. Try dropping all of your timing maps around 5 to 10 degrees across the board and go for a drive. No need to give it a hard time, just try around the same areas where you pick up false knock. I would almost guarantee it will be much worse! So, doesn't that go against everything we know about knock and the knock control? Retarding timing a little should eliminate any chance of seeing knock, yet the knock control picks it up as being much worse. Now do the opposite, try a little extra timing in the same areas and watch it drop away to almost zero. Defies logic.[QUOTE]
You know what I noticed this as well but dismissed it as being something else. I changed a lot of setting while also increasing the timing in this range. I turned up all the timing in the lower ranges so I could have a little more power while cruising and noticed the knock count did go down but is still there.
Nov 6, 2008, 09:00 AM
#203
I had some NGK 8's gapped WAYY too much once and it misfired like crazy at idle to the point that I couldn't drive the car and I never had a single count of knock. Doesn't a misfire cause a different audible result than detonation? I think the filters would be set to focus only on the detonation? I could be wrong, just throwing it out there.
Nov 6, 2008, 09:53 AM
#204
talking about this,two days ago i upgrade from 94170008 to 94170015,the knock filter map 1 is different on the 94170015,i just left it like that and i flash the car,well the car just started knocking all the time,36 knock all over.....i flashed the 94170008 again to see if it fix the problem and still it didnt,i drove the car for the day and all of a sudden the car went back to normal again,no knock....so like you guys are saying,could it be the knock sensor just relearn again??? could that explained the problem i had
Nov 6, 2008, 03:19 PM
#207
Whn the engine is idling it kind of sounds like someone is taking their fist and banging it against the front of your bumper with light force. That subtle thud noise, its certainly hard to explain lol. Soft subsonic thuds.
While boosting it basically feels like the power breaks up. I bet streetfire or youtube will have some video clips to give you an idea.
Generally a misfire is when the mixture failed to ignite at all so basically...no explosion. Detonation is when the mixture DOES ignite but generally in 2 different places at the same time. Thats not the Websters dictionary version but you get the idea,lol.
While boosting it basically feels like the power breaks up. I bet streetfire or youtube will have some video clips to give you an idea.
Generally a misfire is when the mixture failed to ignite at all so basically...no explosion. Detonation is when the mixture DOES ignite but generally in 2 different places at the same time. Thats not the Websters dictionary version but you get the idea,lol.
Last edited by Jack_of_Trades; Nov 6, 2008 at 03:22 PM.
Nov 6, 2008, 03:26 PM
#210
I remember the first time I ever experienced it years ago in my DSM...I turned the boost up to 28psi for the first time and got that fuel cut feeling at about 5500RPM or so. It was a 'throw you through the windshield' type feeling, but more subtle I would agree, because the misfire may happen a few times along with normal combustion, where fuel cut just plain old stops the combustion and does throw you through the windshield.
