Knock Retard and false reading?
Melting Slicks
Joined: Jul 2001
Posts: 3,284
Likes: 3
From: Southwest Florida
Re: Knock Retard and false reading? (RonWhite)
I'm not quite sure what the conditions were (how high you were revving) and whether you are asking if the shift can cause knock retard at the time... or whether you are asking if doing that and overrevving can cause knock retard later? I assume you are referring to the shift itself causing knock retard due to just shifting to another gear. Knock retard often happens around shifts due to the fact that the PCM is modifying the timing by a large amount.
Any time a shift occurs (up or down) there is a large change in RPM. With that change in RPM comes a change in timing advance. If you are on the edge of knock retard anyway, a shift can cause it to rear it's ugly head as the PCM tries to apply the new timing advance from the curve.
Mike
Any time a shift occurs (up or down) there is a large change in RPM. With that change in RPM comes a change in timing advance. If you are on the edge of knock retard anyway, a shift can cause it to rear it's ugly head as the PCM tries to apply the new timing advance from the curve.
Mike
Thread Starter
Pro
Joined: Aug 2001
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From: Staten Island NY
Re: Knock Retard and false reading? (mchaney)
It appears that th KR happened right aroung where I hit the shifter 3,000 rpm! It was fine the rest of the run so I wonder if a shift into 2nd quickly back to 3rd would cause this on a A4?
Team Owner
Joined: Mar 1999
Posts: 28,753
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From: San Jose/Bear Valley CA
CA Events Coordinator
Re: Knock Retard and false reading? (RonWhite)
Get a hold of Team ZR1 and ask him about this... he can help you with the best of them on this topic.
vetterdstr :cheers:
BTW, I like the color combo of your car. ;)
vetterdstr :cheers:
BTW, I like the color combo of your car. ;)
Le Mans Master
Joined: Jan 2001
Posts: 6,429
Likes: 1
From: God's Replica
Re: Knock Retard and false reading? (RonWhite)
I doubt you would get KR caused hitting the shifter into d3 form d2, but you do get torque management kicking in. On the shifts it will pull timing. I have seen it go to a -1 degree from a 28 degree on shifts.
Le Mans Master
Joined: Jan 2001
Posts: 6,429
Likes: 1
From: God's Replica
Re: Knock Retard and false reading? (RonWhite)
How many degrees of KR are you getting and what does your timing go to? Could be false KR. I just do not think that the senors are that sensitive to pick that up. I guess tap a few runs doing exactly the same shift and see what it shows. See how consistent it is.
