I have a 2002 tahoe 5.3 Vincie tow cam. I noticed when ECT is cold I knock excessively. I do not have knock issues when at operating temperature. I used the info from BLUEGOAT06, to understand the basic principles of how the ECT spark correction and modifier table work together, it was huge help.
"2 x 0.80 = 1.6* reduction instead of the entire 2* If the table has a 0, then the feature would zero out the base ECT for that temp. meaning the ECT reduction would be zero. (any number x 0 = 0)."
In the screen shots of my tune, you can see how I went about it.
I also made in excel sheet to double check that I do not pull out to little or too much at any one spot. And to bump it against the Scans to verify that the tables are doing the intended changes.
I know that -8 degrees of timing looks like alot to remove at every engine load from ECT -40 - ECT -176 degrees. However it is best to use the Multiplier to factor in a curve that best works for you.
Remember that both of these tables work together along with High Octane main spark table. So even through the Multiplier table runs against RPM on the y axis and the Correction table runs against engine load. A proper curve still develops because the High Octave main spark table has its Y axis based on load. When paired with the smooth curve of the multiplier table your timing adjustments will be seamless as ECT comes up to operating temperature at every load.
I have added my scan parameters to show how to log Spark advance over and under specific ECT's. This will allow you to verify that the correct amount of spark correction is happening at a specific ECT and load. You can also log your knock events against ECT using the same filter function.
Remember to go slow and verify your work. Every vehicle and engine is a little different so make your own adjustments as necessary.
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