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How to identify ghost knock

 
Old 05-05-2010, 08:15 AM
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Mine had ghost knock around those RPMS as well. Lowering timing didn't change it and power on the dyno didn't show any dips.
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Old 05-05-2010, 09:17 AM
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Greg, I have run more datalogs since the one I sent you and am no longer getting the knock counts at idle. I am now just getting them around 3200 rpm.

I took out the 6 degrees retard we had on cylinder two and the extra fuel we threw in as well. No change in knock counts or how the car drives.

Looks to be ghost knock. Thanks guys!
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Old 05-05-2010, 09:27 AM
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You might want to leave a couple degrees of retard on cylinder 2 just in case some of those knock counts were real. The calibration that you and I created does have more agressive timing than stock, so it's better to be safe than sorry. I guess we'll know more when you change the spark plugs. Make sure to check the plugs that you remove for signs of detonation.
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Old 05-05-2010, 02:01 PM
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what kind of threshold(volts, 0-5v) are you guys using to identify knock?
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Old 05-05-2010, 03:03 PM
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Originally Posted by maluch,May 5 2010, 04:01 PM
what kind of threshold(volts, 0-5v) are you guys using to identify knock?
We are just looking at the "Knock Count" values in the FlashPro datalogs. I don't think the voltages are available.
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Old 05-06-2010, 08:04 AM
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does knock count mean it actually pulled timing? my car sees up to 2 volts of knock up to redline, its not a big deal. look at the knock voltage table, so you can see rpm vs knock voltage and when it starts to pull timing.

as rpms go up, ussually the table will allow for more knock before it starts to pull.
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Old 05-06-2010, 08:38 AM
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There was not any knock retard, since we reduced the knock sensitivity in the tables.
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Old 05-13-2010, 08:34 AM
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anyone use any aftermarket knock sensors, ones that can discriminate based on frequency? if so, which one?
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Old 05-14-2010, 06:18 AM
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Originally Posted by gernby,May 3 2010, 01:39 PM
The knock tables can be adjusted to change the knock retard, but they don't seem to have any impact on the actual knock counts. The knock counter really seem pretty independant of the rest of the system.
^^ i mentioned this in another thread, yes it has ZERO effect on knock counts. Only ignition retard
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Old 04-15-2015, 09:50 AM
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Originally Posted by S2Dave View Post
Greg, I have run more datalogs since the one I sent you and am no longer getting the knock counts at idle. I am now just getting them around 3200 rpm.

I took out the 6 degrees retard we had on cylinder two and the extra fuel we threw in as well. No change in knock counts or how the car drives.

Looks to be ghost knock. Thanks guys!
What do you mean by 'no change in how the car drives'? Did it not lose a lot of torque at that load/rpm? If so, wouldn't it be better to leave the 6 degrees out?
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