Why is the timing advance in the log much higher than in the table?
I recently dynoed a friend's basically stock 5.3L pickup and noticed that the timing advance in the log was noticeably higher than what was specified in the timing tables. The log showed 20-24* advance with Dyn cyl air in the 0.7x g/cyl range. The table calls for timing advance in the mid teens which seems kinda low to me, but I can't seem to find the discrepancy. I've looked at the spark correction tables, but nothing in there seems to make up the difference. Please see the attached tune and log file. I appreciate any good feedback or info.
Ahh. I see now. Thanks. For a boosted application, do you think it would be wise to zero out the AFR spark correction and just tune the timing with the spark table?