Never at any throttle setting above idle. For closed throttle or coast conditions up to 44 degrees is fine because there is little fuel or air being processed and high vacuum, so burn rates are very slow. Helps prevent popping and banging on long coast, and in the car helps keep the cat temps up, and best of all reduces HC so you can buy one in California. For anything involving power then 27 degrees for higher octanes and 22 to 24 for low octanes.

 

Lynn E. Hanover

 

 

Lynn, is there ever a need for the spark advance to go past 30?  This is a graph of a couple of the short runs I was making today.  The advance goes up to 33.2, but it went as high as the mid 40's.  It is so erratic, because it is hitting up against the rev limiter which I had set to 3600RPM. It uses a fuel cut algorithm, which is why it is so choppy.

I need to get it running with less throttle, so I don't have to have it open 35%, then I can get a cleaner graph...but I'm just wondering if I need to beat back that advance first.