Because you are almost always better off with a curve. The ignition box retards with RPM, and when that retard starts and how much it retards varies with every box.
Ignition timing at peak torque and peak HP aren’t the same.
Interesting. I've never heard of that. My MSD Digital 6 box never retards the timing, but I only rev to 7000 rpm. It starts at 35* and hits the rev limiter at 35*. It does have the capability for things like N02 and a High Speed switch retard etc. Is that what you mean?
Prior to locking out my MSD, I had 22 initial and the rest of the mechanical to reach 35* was all in by 2000 rpm. I never really drive with the motor below 2000 rpm though, and certainly never fully load it below 3000 rpm.
