I'm running an ARAP bin on a 89 350 TPI swap in my 87 Monte Carlo SS. I have a question about the spark table. Does the ECM add or subtract the base timing from the values in the table to arrive at the final timing figure? Or are the values absolute with no regards to what the base timing parameter is in the scalars? I'm just trying to learn more. Have not been able to find any info on this specific question.

 

I believe the values are absolute, meaning, if base timing is 6 degrees BTDC and the table calls for 32 degrees advance, the ECM will add 26 degrees advance to the base 6 degrees to get the 32 degrees commanded. This is why your base timing should match what the base timing is in the BIN. HTH!

 

Thanks, Bigal55. That does make sense.