GM SmartCoils redux

[garfield at pilgrimhouse.com]

On Wed, 24 Jun 1998 19:01:23 -0500, Terry <thartman at gte.net> wrote:

>> I have nary a clue as to what an ICM is; never heard that before, unless
>> you mean just a "module". 
>
>Hmm..  a friend of mine has a '98 LS1 F-body and the Helm manual.  
>There is some device referred to as an ICM in the Help(helm) 

All I've looked at is the wiring diagram for the '97-'98 Vettes. I dunno
what this ICM is; are you SURE the "I" stands for IGN?? Could easily be
the Idle-air Control Module, for all I know. On the Vettes, the IGN coil
signals go directly from the PCM to the coils. End of story. Mebe diff.
on the Z-28s, I dunno.

>Ok good enough - so for a "retrofit" project where I want to elminate 
>the distrib, would the new SDI from Electromotive(ducking ;) ;)) be 
>worth looking into?  Any "insight" ;) on the SDI in the archives? if so 
>I can look it up....

Yer such a sensitive guy, Terry. Heh. I dunno WHAT is in the archive
concerning Electromotive. I was just tryna ward off the potential thot
that a retro from a dizzy to these coils is "easy". Now that I've heard
more from you, I can see I needn't have worried about THAT, per se. So
yeah, it's the same issue really, for ANY transition from a dizzy to
crank fired or crank/cam timed.

Since MOST guys doing this transition will HAVE to go to some
aftermarket controller, I'd rather have said just about ANY aftermarket
controller is gonna allow you to take advantage of these coils. Here's
why.

Regardless of what BRAND you pick, if the IGN timing is part of the
controller, you're either gonna get PAIRS of coils to fire or COILS to
fire, outta your aftermarket ECU. With these new smart coils, mox nix,
either way is fine, you either connect the "pairs" signals to two of
these coils (hopefully the RIGHT pair 8), or you connect the "coils"
signals to each of these coils, and you're DONE. No modules, not nuthin
else, just the ECU and the coils.

I suppose the real question is, what ARE the normal IGN outputs you find
coming out of these Electromotive, FelPro, SDI, Accel, blah blah
systems? They're normally intended to fire some MODULE, either a
per-coil module/ignitor(for the euro/jap guys in the house) or a
wasteFire coil module. Either way, you can just use this signal to wire
directly to the coils now. The bottom line is, you've eliminated any
"modules/ignitors" from the picture. Not to mention that as that other
post I've mentioned points out, these coils are both CHEAP and light,
and nice to mount and wire HV-wise.

HTH
Gar