Yes there is no question the test rig was failing the RX8 coils.

They don't like an out in the open spark anywhere around them
They continually re-trigger and the dwell becomes infinite.
Then they soon over heat lickity split and fail permanently.

I just got another 3 out of my RX8 and all were discolored.

I am working on a heat sink solution for cheap RX8 coils
if you don't want to use the MSD versions. Either will work
on the heat sink. A small 1 inch square 12 volt fan
is optional on the heat sink.

The waste spark is problematic on the trailing coils
of a rotary but will work on the leading coils. The 2nd gen
RX7 engine was waste spark on the leading coils. I have not
bothered to test the Ford stuff as I must be sure it is
a long term solution and not based on obsolete parts if
possible. The coil on plug seems to be the long term
solution for the future.

Paul Lamar

All this time and work to find a solution to cool a defectively designed
coils; plus projecting that all coils have a cooling issue when it seems
to my simple mind; using the D580 coil which has had none of those
problems (at least that I've heard of) would solve it.

Brian

Well not yet. Remember the problem took 30,000 miles to show up
in a car that averages only 3,000 RPM. The fact of the matter is
the D580 was designed to fire half as often as we are asking it
to do. It cost more to design something that is over kill by
100%. There is no evidence the bean counters will let them get
away with it. As I said, do the numbers and you will find
the 580 is near full on current all the time. The RX8 coil
was designed to fire twice as often as a rotor fires once
per rev while a piston once every two revs.

The primary resistance is .57 ohms. If the current is on all
the time and E = I x R that is 21 amps. I don't know about
you but that is a scary number to me. :) The power is
E x I which is 252 watts. Next time you get a chance grab
a 250 watt light bulb when it is on :) I am building heat sinks
for mine.

Paul Lamar