Lets say that I have 8* base timing (gotten by timing the engine with the EST wire disconnected) and I have 32.0 degrees in the advance timing table at high RPM and high engine load. Is my total timing actually 40 degrees or is it still just 32 degrees? And I forgot, I have 8 degrees in the reference table for base timing.

 

8 deg initial timing or base timing is neither added nor subtracted. But I guess it may be in a calculation ECU does. It just tells the ECU the position of the distributor so to speak. Your engine will see 32 deg at WOT and your datalogs should confirm at 32. Likewise if your idle SA is 24 then 24 is what you see in datalogs. Somewhere there is an explanation as to why one does not set base or initial timing at zero.

 

Thank you for the response.

 

In the Tuning Guide Book sticky, chap. 5, under the '8063/'8746/'7747 ECM is a spark logic write up. Explains how the ECM uses the spark tables/parameters and arrives at the final SA value.

RBob.