I don't think we have one? Timing is fixed. PCM determines spark advance. I think it's called a Direct Ignition System. Coil, crank sensor, cam sensor. Along with those and a boat load of other inputs the PCM determines advance. maybe that wasn't the question.
19 degrees BTDC stock before PCM adjustments, 22 degrees Diablo canned tunes before PCM adjustments 24 degrees B&G canned flashes before PCM adjustments PCM adjustments are knock retard, IAT,Ice torque management etc. All this gets thrown out the window on a custom tune, I myself am testing at 28-30 degrees BTDC. Another thing I'm researching is how far back the stock PCM will pull the timing back, I have programmed a total of 36 degrees BTDC and have seen the PCM pull 8 degrees out of that ............. I'm still looking for all the answers.