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What to do with knock sensors?

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Old 08-24-2004, 02:16 PM
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Default What to do with knock sensors?

I have a very aggressive motor, which is about to be tuned. I am thinking that the knock sensors need to be unplugged totally. What do I need to do besides just unplug them?
Old 08-24-2004, 02:54 PM
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I say leave them in but first thing in the tune, cut
the amount of KR they can push to 1 degree,
decrease the attack rate, increase the decay rate
and kill the burst knock temporarily.

That way you still have the KR as your "canary"
to tell you about whether you have overstepped
on spark. This is more useful, if you are going to
log data on the pull, than trying to listen for the
sound of detonation.
Old 08-24-2004, 10:13 PM
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Originally Posted by jimmyblue
I say leave them in but first thing in the tune, cut
the amount of KR they can push to 1 degree,
decrease the attack rate, increase the decay rate
and kill the burst knock temporarily.

That way you still have the KR as your "canary"
to tell you about whether you have overstepped
on spark. This is more useful, if you are going to
log data on the pull, than trying to listen for the
sound of detonation.
Exactly the kind of technical response I was looking for. Thank you !
Old 08-25-2004, 02:49 PM
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Originally Posted by jimmyblue
I say leave them in but first thing in the tune, cut
the amount of KR they can push to 1 degree,
decrease the attack rate, increase the decay rate
and kill the burst knock temporarily.
cut the amount of KR they can push to 1 degree == Max KR vs Load
decrease the attack rate == ? Attack vs RPM? Attack vs Temp? Attack gain vs Altitude? Which one?
increase the decay rate == Decay vs RPM
kill the burst knock temporarily == ??? Knock allowed time? Noise Level?
Old 08-25-2004, 03:10 PM
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I only know about HPTuners.

Set to =1 across the board
Max KR vs MAP (Not in Power Enrich)
Max KR vs MAP (in Power Enrich)
Max KR vs RPM
Burst KR vs RPM

Set lower
Knock Fast Attack Rate vs RPM - I reduced to 0.2
from ~0.5 for less "jump up" on transient knock
events (persistent knock will still pump it up)

Set higher
Knock Fast Recovery Rate vs RPM - I increased to 0.1
from ~ 0.015 for faster "go away" when no knock
Burst Knock Enable Delta CylAir Threshold vs RPM -
I increased this on the truck I tuned the other day
because it had very low threshold, like 0.01 (my SS
has 0.02); so far I have not been able to find out
that the timebase is, here; want to figure out what
the deltaCylAir is under WOT acceleration and put
the threshold above that, so it only acts on throttle
opening and not the whole pull. Also do not see any
params in HPTuners that tailor how fast Burst Knock
decays or how long it persists though I expect these
exist.

How these all map to LS1-Edit I couldn't say, maybe
this is close enough for someone to translate? At any
rate this is only a suggestion based on something that
worked for me; once the tune is bedded in you would
probably want to open the KR params back up a bit for
bad gas and hot weather, etc. on the street.



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