Initial timing .vs. ECM timing

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Jan 31, 2001 | 10:13 AM
  #1  
I've been looking at my spark tables and find the advance numbers to be quite high. In my case, they range from 20.0 to 40.1 degrees! Do these values represent the amount of advance provided by the ECM in addition to the initial timing? If you set your initial timing to, say 10*, that would result in over 50* of total spark advance! That doesn't sound right at all! I have been under the impression that total timing should max out in the low-to-mid 30's.

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'87 IROC 5.7l TPI - original owner!
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Jan 31, 2001 | 01:27 PM
  #2  
Quote:
Do these values represent the amount of advance provided by the ECM in addition to the initial timing?
No. The ecm subtracts the factory initial (6degrees) from the total timing calculation.

Quote:
I have been under the impression that total timing should max out in the low-to-mid 30's.
More timing can be tolerated during light cruise situations.
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