I hooked up a simple test rig, where substituting resistors , I was able to determine the firing point for each of the coils, and low and behold, the HAAS ones need twice the amount of current :-
Logic level +5v current limit set @ 16mA- NOT FIRING!!
Logic level +5v current limit set@ 25mA Fires
Logic Level +5v unable to determine bottom end limit, but fires as low as 2.5mA .
If this is the case for the new BERU coils arriving I'm in deep doodoo
It looks like if I want to allow for OEM coils, I need to cover all bases, and add some additional drivers to the logic outputs from the MSX.
I have found a few mentions of this, but as by nature of the forums , nobody has published a circuit diagram, and what components to use.
I'm running full sequential of the MSX card, I dont want to go wasted spark due to the messy coil HT leads crossovers , so just want something in series to give the outputs a "boost"