Am I wrong in assuming that the main fuel table #2 - VE adder is added to the table #1 VE at WOT??? And can someone tell me how exactly the main spark bias constant affects timing.

TIA

 

VE1 and 2 are added together all the time.

Main spark bias is subtracted from the total timing calc. If you are using Tunercat, the main spark table reflects this subtraction. No need to change this value.

There is a timing doc over at DIY-EFI it explains the 7747 spark control. Good reading.

 

Thanx, and..... if the 2 VE tables are always added shouldn't I be trimming them both equally?? There must be a purpose for the second table that I haven't figured out yet.

 

My guess is they did that so they could control the VE tables using different methods. You can control an entire RPM range using the VE#2 table.