high low octane tables spark advance
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high low octane tables spark advance what happens or what conditions are met
in the pcm when it makes the switch
from low to high or high to low octane spark tables
in the pcm when it makes the switch
from low to high or high to low octane spark tables
ther's a good description in this forum somewhere...
basically it's not switching. the PCM reads the knock sensors and decides to set the timing somewhere between the high and low octane table.
no ping = high octane.
it fully goes to the low octane table if you disconnect the MAF.
basically it's not switching. the PCM reads the knock sensors and decides to set the timing somewhere between the high and low octane table.
no ping = high octane.
it fully goes to the low octane table if you disconnect the MAF.
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You start off with full (high octane) advance. There is a value in the PCM that slowly increments down based on how much knock is detected, and slowly recovers if no knock is hear. The value would be somewhere in the middle between the high and low table, and will be closer to one value or the other based on how much knock is heard. Halfway between the two would pretty much be an average.
What I don't understand is why some values in the low octane table are higher than in the high octane table.
What I don't understand is why some values in the low octane table are higher than in the high octane table.
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From: North Carolina
Originally Posted by Another_User
You start off with full (high octane) advance. There is a value in the PCM that slowly increments down based on how much knock is detected, and slowly recovers if no knock is hear. The value would be somewhere in the middle between the high and low table, and will be closer to one value or the other based on how much knock is heard. Halfway between the two would pretty much be an average.
What I don't understand is why some values in the low octane table are higher than in the high octane table.
What I don't understand is why some values in the low octane table are higher than in the high octane table.
would there be any benefit in making the low octane table
lower if you always run 93
say you ran through a bad tank of gas
Ive read alot about copy + paste the high to the low octane table.
Is this only done during initial tuning and changed once tuning
is complete, or just left as is?
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It depends. The only benefit would be, if there was real knock, less of a chance of damage to your engine. A lot of us just copy the high to the low and forget about it and enjoy the extra power. You will still get normal knock retard, just none if it "sticks" permanently. If you go speed density it always runs off the low octane, so you have to copy the high over top of it.
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