I have played around with the EOIT boundary to reduce or remove the raw fuel mixture being sent out the exhaust valve with my new cam (has 8* overlap).
Now I am trying to be scientific about the values I really need based on my new valve timing events. I have my cam card so I know what they are.
My question is not so much what target angle to use, but how the ECM calculates it based on the 3 tables- Boundary, Normal ECT, and Normal RPM.
In the stock tune I know that GM targeted to inject all fuel before the intake valve opened for better atomization.
1. The way I understand the tables to work is Boundary + ECT - RPM = actual EOIT. Now after further review, I'm not sure this is correct. How is EOIT calculated?
2. Also, what do the crank angles referenced from? Is 0* TDC of the compression stroke? Or something else? If it was 0* TDC compression, then the stock injection boundary of 520* would place it at the tail end of the intake stroke, which does not match GM's approach to finish injection prior to the start of intake stroke.
Once I understand these 2 questions, then I can calc where my EOIT settings need to be.