I am running spark, using the timing map similar to ner's and under high loads on the engine and over 10psi, I get a backfire type studdering at about 5k and up -could this be the timing map or is it more likely plugs/wires or coil pack. I am running stock wires and coil pack and have my plugs gapped to .025. I have my afr right at 11.5

What sounds should i be listening for beside detonation when i am tuning the map and what adjustments need to made when those souds are present.

I am trying to eliminate whether it is software or hardware.