Torque Knock PID - may have some progress...
- Thread starter ecoboostsho
- Start date
ecoboostsho
New member
Thanks guys...!
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Sent from my XT1060 using Tapatalk
ShoBoat said:
I know some of discussed KR on abrupt throttle lift. I do not believe that is detonation at all. Unless someone can provide a logical reason for spark knock under a closed-throttle and no load condition, I maintain the sensor is just picking up "noise" that is not spark knock and not harmful.
Agreed. I have been logging for a few days now. I believe that KR we could be seeing is at least in my case directly related to IAT2. If it's above 60C I will get a bit of KR. In the area of about 2 or less. Last night after sitting at a long traffic light I did a 1/2 pedal run to the limit and had KR of 2 through part of 1st gear. IAT2 was at 67C.
ecoboostsho
New member
Okay I think I've figured it out. I did quite a bit of logging on the way to work with FORSCAN. First I agree with ShoBoat...I typically only see maybe a blip or 2 of knock at part throttle but it does seem temperature dependent...with the outside temps in the 70s this morning and running at highway speeds I honestly had a hard time generating any knock. If I let the motor heat soak I can see 2 or 3 degrees.
As for the equation it wasn't really far off at least compared to FORSCAN (sorry for anyone hoping it was if you've got a +7 reading). After numerous logs and serial captures the PID does use both the A and B parameters in the equation. The B is the 1/4 degree part...just took some thinking.
I still need to go out and verify this but I believe this is close...The sign may be off though but either way it would only be off up to a 1/2 degree...
Signed(A)/2+(B/512)
This would result in readings from -3.75 to +7.25 degrees of timing added or subtracted accordingly. The bad news in this is if you are getting 7 degree of knock I do believe the "reading" is accurate...it doesn't mean it's actual knock though...just that the knock sensor is picking up something it thinks is knock. However if you go back to stock and the knock goes away I believe it was sensing real knock as opposed to the throttle body shutting etc...just my thoughts.
As for the equation it wasn't really far off at least compared to FORSCAN (sorry for anyone hoping it was if you've got a +7 reading). After numerous logs and serial captures the PID does use both the A and B parameters in the equation. The B is the 1/4 degree part...just took some thinking.
I still need to go out and verify this but I believe this is close...The sign may be off though but either way it would only be off up to a 1/2 degree...
Signed(A)/2+(B/512)
This would result in readings from -3.75 to +7.25 degrees of timing added or subtracted accordingly. The bad news in this is if you are getting 7 degree of knock I do believe the "reading" is accurate...it doesn't mean it's actual knock though...just that the knock sensor is picking up something it thinks is knock. However if you go back to stock and the knock goes away I believe it was sensing real knock as opposed to the throttle body shutting etc...just my thoughts.
glock-coma
New member
I will also try the new equation and post results. I'll try going back to stock and looking at kr numbers. Thx for all your help and effort on this.
Finding that the equation is/was accurate is not a disappointment for me even though I was one of the ones to register a 7 positive. It just makes me extremely grateful to have been lucky enough to have a KR gauge in service that did give me a heads up. I was much closer to the edge than I care to think about. I could have been blissfully ignorant. I have not updated to the new equation yet as my car is at the dealers for some tranny TSB issues but having flashed back to stock in advance of this dealer visit I can say that I now have generated a max of positive 1 reading so far on the stock tune. Thank again ecoboostsho for the life saving gauge and once again for vetting the equation when the serious readings surfaced! Very appreciative indeed!
ecoboostsho
New member
Say what?? 
I tried it all the way home and got pretty normal results...are you sure that you don't have a space between the signed and (A)??
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I tried it all the way home and got pretty normal results...are you sure that you don't have a space between the signed and (A)??Sent from my XT1060 using Tapatalk
ecoboostsho
New member
My bad...you are correct. I had the same thing in Torque...just typo'd the equation here (well actually I went from memory and you can see how well that worked out.)ShoBoat said:
I have seen it add timing on light throttle in quarter degree increments...-.25, -.5,-.75...all the way to -4.0. I have seen 2 or 3 degrees of positive knock when heat soaked as indicated before. Interestingly it actually reads in finer increments than .25...occasionally I see .18 or .36 etc...seems to respond faster but that's probably just because the B variable is giving us finer resolution. I will keep testing but it seems promising.
ecoboostsho
New member
Also just to clarify Torque will round this off for you depending on how many decimal places you have. I did notice the gauge which shows max and mins is fixed to one decimal place so it will appear in tenths. That is more than sufficient for our purposes though.
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ecoboostsho
New member
Flashed to stock? Very well could be...no one knows how much timing the car actually adds under light throttle?FoMoCoSHO said:
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