better spark circuit swap IGN and IAC2B
 

Another question.. Thanks for your patience and help...

on the miata turbo wiki
http://miataturbo.wikidot.com/MS2_a

They swap the IGN and IAC2B from Joe's circuit

https://www.miataturbo.net/megasquirt-18/better-spark-out-circuit-33964/

Why is it swapped?

The way an MS1 is normally set up fires Miata coils in the opposite order compared to how an MS2 or MS3 is set up.

dont question, just accept.

Pretty much what Ben said.

The "classic" DIYAutoTune wiring of the ignition system puts "Spark A" on the 2/3 cylinders, and "Spark B" on the 1/4 cylinders. Depending on your point of view, that could be considered backwards. However, they also set up the decoding of the CAS "backwards", so it all evens out in the end.

I personally wired my ignition the "correct" way, as I'm running a 36-1 crankwheel with the missing tooth in the traditional location (just prior to TDC), therefore my firing order cannot be reversed in software to compensate for reversed wiring.