Low impedance waste spark coils?

[Clay Buccellato (Anthony)]

> We're currently using the Ford units for aircraft applications and haven't yet
> had problem that we are aware of.  Where did you hear that the insulation breaks
> down on the secondary side?  I'm currently dumping a 1.5uFd Cap sitting at 225V
> into it through a triac.  Works great.
> John

I heard of the secondary insulation deficiencies from Lance at
Speed-Pro, in regards to the GM coils he was using. He built his own CD
unit, and the coils sparked really well... for about five minutes. Do
you happen to know the primary winding impedance of the Ford coils you
have?

I believe some of the aftermarket systems drive as high as 470V into a
0.1 - 0.2 ohm primary. I don't know the size of the capacitor.

What I'm looking for are "race" ignition coils with low primary
impedance, that are capable of being driven very hard by a high voltage
CD system. Also, I would like the well proven multi-spark feature (from
the coil driver unit, of course). Experience has shown me that hot
ignitions are well worth the effort. I want to make sure I purchase the
best components.

Electromotive has a nice waste-spark system with spark sorter, from
which they claim 120 millijoules spark energy, and a long spark
duration. Emotive coils are moderate-impedance (.3 - .4 ohms primary
side), and are switched 14V inductively. As a point of reference, the
Crane PS-92 coil has .2 ohms primary.

Have you looked into any coils other than the Ford units? What made you
select them? I take it you haven't tried driving them really hard with
an aftermarket CD box? (not that 225V isn't good for driving a coil, but
higher energy units have been built. I'm going racing, so I've gotta get
the really hot unit).
-- 
                                      -Clay