Fast shifting knock is something to consider.
mine is stock clutch.
I am leaning toward the idea that stock knock sensor filter map isn't that good when the car is modded.
My knock counts and S-AFC knock counts usually correlates very well. But when I had this 23 counts of knock S-AFC didn't show any unusual knock counts. oh well, S-AFC isn't proven to detect knocks anyway.
I am leaning toward the idea that stock knock sensor filter map isn't that good when the car is modded.
My knock counts and S-AFC knock counts usually correlates very well. But when I had this 23 counts of knock S-AFC didn't show any unusual knock counts. oh well, S-AFC isn't proven to detect knocks anyway.
Originally Posted by honki24
so share your knock filter map experience... you have an interesting one.
Bump becuase of recent tune event.
To be clear this is still something I have yet to experience in my IX to any great degree. When I get home I intend to cross reference the knock filters between the car in question and mine (05 vs. 06). On too what I logged.
Yesterday afternoon I was tuning a friend's 05 that he had just picked up. It came to me with WAY advanced timing (10* at peak torque, 21* at redline) rich fueling, and the boost turned down to 14psi because otherwise it ran like crap, go figure. So I proceed with my normal tune strategy of assembling a basemap that should be close. It had an aftermarket intake which since I dont have I have never tuned for before and had to guess.
Long story short- Dropped timing to 2* at peak torque with 15* by redline turned boost up, took some fuel out. I disabled lean spool to keep things consistent and then we went for a drive. After about 3 hours I got a tune that I was comfortable with that wasnt knocking in 3rd and 4th gear pulls, felt good, and was up to 22-23psi on pump.
We went out one last time and downshifted from 4th to 2nd at about 40-45mph and I didnt notice it in any of the other logs, but there was a 31 count spike in knock from the downshift. It decayed rapidly to 17 and then down to 10 but not before it had dropped my already "conservative" timing to -3*. I wasnt able to check DP clearance (though I suspect this might be something of an issue), or actually knock sensor voltage.
I am curious if anyone else has figured out a probable cause? There was some knock in my first map, 9 counts, that failed to decay timing at all, and then after tuning it was all gone until this. AFR's were 11.1-11.5 on good fuel, timing was curved modestly, car has usual suspects (TBE, filter, etc.)
To be clear this is still something I have yet to experience in my IX to any great degree. When I get home I intend to cross reference the knock filters between the car in question and mine (05 vs. 06). On too what I logged.
Yesterday afternoon I was tuning a friend's 05 that he had just picked up. It came to me with WAY advanced timing (10* at peak torque, 21* at redline) rich fueling, and the boost turned down to 14psi because otherwise it ran like crap, go figure. So I proceed with my normal tune strategy of assembling a basemap that should be close. It had an aftermarket intake which since I dont have I have never tuned for before and had to guess.
Long story short- Dropped timing to 2* at peak torque with 15* by redline turned boost up, took some fuel out. I disabled lean spool to keep things consistent and then we went for a drive. After about 3 hours I got a tune that I was comfortable with that wasnt knocking in 3rd and 4th gear pulls, felt good, and was up to 22-23psi on pump.
We went out one last time and downshifted from 4th to 2nd at about 40-45mph and I didnt notice it in any of the other logs, but there was a 31 count spike in knock from the downshift. It decayed rapidly to 17 and then down to 10 but not before it had dropped my already "conservative" timing to -3*. I wasnt able to check DP clearance (though I suspect this might be something of an issue), or actually knock sensor voltage.
I am curious if anyone else has figured out a probable cause? There was some knock in my first map, 9 counts, that failed to decay timing at all, and then after tuning it was all gone until this. AFR's were 11.1-11.5 on good fuel, timing was curved modestly, car has usual suspects (TBE, filter, etc.)
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Joined: May 2006
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From: UK
I get a lift off knock from high boost if I don't retard the timing in the 100-200 load range. In places it needed 5 degrees off JDM timing to fix. It was octane, heat and ignition responsive, and I could hear the distinct sound of detonation in the cabin on the worst examples. This was no phantom knock on my car.
If I could reduce the ignition attack rate on lift off I would be able to fix it that way, but I find no setting for this, it just uses the timing in the load cell it is passing through even if that means it jumps from say 10 degrees to 28 on the next datalog point.
If I could reduce the ignition attack rate on lift off I would be able to fix it that way, but I find no setting for this, it just uses the timing in the load cell it is passing through even if that means it jumps from say 10 degrees to 28 on the next datalog point.
I went out and logged a few things today.... first was a stutter box launch.... my stationary limit is set to 6000 and the darn knocks like crazy even if only for 1-2 seconds.
The second thing I logged was a no lift to shift gear change. Again knock went through the roof! For the record NLTS is MUCH smoother than a normal shift so its not stuff banging around I believe its bad things going on in the motor.
That being said on a normal lift and shift I rarely if ever get knock.
The second thing I logged was a no lift to shift gear change. Again knock went through the roof! For the record NLTS is MUCH smoother than a normal shift so its not stuff banging around I believe its bad things going on in the motor.
That being said on a normal lift and shift I rarely if ever get knock.
Bringing this back...
I was out ogging the other day and did a run from 1st-4th. I'm hitting an insane amount of knock every time I shift. Nothing is touching or rattling to cause phantom knock (I even went so far as to remove the bars under the downpipe to be sure).
Plugs are still in good shape. Fuel is 92oct.
I can post up the logs later.
I was out ogging the other day and did a run from 1st-4th. I'm hitting an insane amount of knock every time I shift. Nothing is touching or rattling to cause phantom knock (I even went so far as to remove the bars under the downpipe to be sure).
Plugs are still in good shape. Fuel is 92oct.
I can post up the logs later.
Define: 'insane amount of knock'
I occasionally get shift knock in 4th gear. But I've never had a huge problem with it after installing things like the rear diff bushings, and poly exhaust hangers.
Is this a reoccurring problem? Did you do another pull to see if it was a fluke, or the car was just real hot, and maybe going up hill? Basically does it do this on every 1-4th pull? Or was it out of the blue?
I occasionally get shift knock in 4th gear. But I've never had a huge problem with it after installing things like the rear diff bushings, and poly exhaust hangers.
Is this a reoccurring problem? Did you do another pull to see if it was a fluke, or the car was just real hot, and maybe going up hill? Basically does it do this on every 1-4th pull? Or was it out of the blue?