well, if you look at the tables I posted, you will see the vertical row identifiers. Those are load %'s. The Horizontal column identifiers are RPM. The numbers in the chart are total timing values... not including any adders/subtractors.
So by looking at the T4M0 table, versus the J4J1 table, you can see certain low load areas of the table have from 11? to 21? MORE timing... This was done for emissions purposes, but also increases the likelihood of detonation.
Like I said... you cant fix the detonation with the engine... its all in the tune.
As for why your car wont make much power... SBF's are known to make best power around 34?-36? BTDC total advance. that 4-8? can make a HUGE difference in the power production of your car.