How much compression with a Magnum?

Just curious: Any ideas on why the 112 does not do better at idle, or is it just the combination of that with the duration and too much overlap?

It only applies to factory injected engines, the factory pcm can be flashed to deal with a 112 to 110 duration at 50 but the lower you go, the higher idle you have to program into pcm. This is mostly beause its a MAP based system, not a MAF based system. MAP uses engine vac signal to determine throttle, load and fuel parameters so if you install a cam that pulls 25% less vac you have to compensate for it, more you go off "normal" the harder it is ot get a good idle.

The aftermarket FI systems typically have a much larger "grid" used in programming, think 720 dpi tv vs 1080 HDLP tv. The factory is a much finer "grid", more lines of code and more finely tuned. The aftermarket systems like FITech use a big grid, chunky style, program which will deal with lower vac signal much better but at a trade off of not being as precise in fuel curve. I think its like 3x3 vs 12x12. Atari 800 vs Playstation 3. A Mega Squirt system is like factory and a much finer "grid", 24x24 if I remember correcctly, thus why its able to run multi port, sequential MPFI either as piggyback or stand alone. If you use one of these, you can deal with smaller LSA much better than even factory pcm's, BUT they wont run a 44/46 RE or factory gauges in say Dak, Dur, Ram or Wrangler due to not having ccd buss.

Too much tech for a sunday :D