If knock occurs reduce advance in that area to stop the knock. Then on the next cycle give it right back. In effect, these systems "ride" the knock sensors.
Essentially what the Utec does...
MAF vs MAP
Seems to me MAP is the evil step-son of MAF.
If you knew the total volume and temperature (averaged pre and post intercooler) of the compressed air the MAP is reading and extrapolated this against RPM, would you not get the MAF value?
Assuming that.... MAF is a function of MAP, and vice versa... similiar the way hp is a function of torque.
I would think our ECU would rely on the "total" package value for tuning purposes rather than extrapolating MAP to MAF, and as such incorporating stacked tolerancing like errors...