Questions

[DRW]

Most people report FE and HP gains by advancing the timing by a few degrees. This tells me the factory uses conservative timing advance to be on the safe side.

At light throttle there is low cylinder pressure, so any knock that occurs at light throttle won't add much more pressure, and the risk for damage, whether cumulative or instantaneous, is low. Likewise the stock knock control in my car's stock ecu is completely inactive at light throttle. I've looked into the ecu code and also found that knock at mid throttle will pull timing, but the ecu gives back the timing almost instantly (1 degree every 0.07 seconds). Knock at WOT pulls timing and keeps it pulled longer (returns 1 degree every 0.75 seconds). If the ecu senses consistant knock it'll subtract a few degrees of timing all the time.

Of course this info is from my specific car and may not apply to other cars, but it's nice to peek at the inner workings of an ecu to see what factory engineers are doing.

[dkjones96]

Originally Posted by DRW

Most people report FE and HP gains by advancing the timing by a few degrees. This tells me the factory uses conservative timing advance to be on the safe side.

Location plays a big role in this. I live at a mile above sea level and pretty much anything on the road can get a boost in power and economy by advancing timing. The Durango is limited to 40 degrees of advance and it does 40 quite often. The drag strip is open for test n tune this weekend and I plan on going there to test changes in timing and some other stuff.