Igniters => DIS

[Bob Wooten]

Puny rear brakes huh?  you are going to give me brake envy, or LBS (little
brake syndrome).  thanks for all the information.  I had downloaded this
DDIS thing before, but my computer had crashed & when the "pro's" @ the
computer store "backed up" the hard drive to reformat it, they did not back
up the "projects" folder.  all the stuff that I had for this (except for the
stuff @ work) was gone.  that will teach me not to put the important stuff
onto CD, (the reason I bought the darn thing in the first place).

thanks for all the info.  I am @ a cross roads now.  I have the timing
circuit done but have to deal with drivers now.  If I can get them all in 1
package why not?  I guess I don't mind drilling holes in my valve covers.
or spose I could make some fancy ole bracket to come down off the super ram.
maybe drill holes right into the super ram, yea that's it.  no, maybe put
them into the super ram & have the coil wires feed through the holes, nah,
that would take a lot of RTV to fill up the vacuum leaks.

time to goto bed I think.
thanks again to everyone,
BW



-----Original Message-----
From: owner-diy_efi at diy-efi.org [mailto:owner-diy_efi at diy-efi.org]On
Behalf Of Jurgen Hartwig
Sent: Wednesday, February 28, 2001 8:15 PM
To: diy_efi at diy-efi.org
Subject: Re: Igniters => DIS


> thanks, if you run across the info on the Motorola chip I would be
grateful.
> I would go search their site but what site do I search (Motorola, Cheri
or
> ON semi)?  if you cant come up with it, I'll get over it.  maybe first I
> will check the archives for the CNP or was the reference to DIS & Waste
> spark?
>

Hello Bob, I brainstormed and remembered where I saw the Motorola chip.  A
fellow from my alma mater, Georgia Tech, designed a DIS system for one of
the school's Formula cars.  The write-up is on the DIY-EFI webpage.  The
portion of the article you need to view is in Portion 2, labeled
"Ignitor." Duh!!! :)  Here is the weblink,
http://www.diy-efi.org/diy_efi/projects/ddis/ddis2.htm

I am no electronics expert by any means, but this looks to be what you are
looking for.  It has TTL input & dwell control, so it appears to fit your
needs.  Please excuse me if I am wrong.

Regarding the CNP, or rather Smartcoil, as it was called in 1998 archives,
here are two pieces you and others might find interesting.  Both below
quotes were written by Gar, I believe of EGOR fame.

"A guy in our Aviation group that
works in a GM lab sent me one of these off a decommissioned test
vehicle, and they are NOT mere IGN coils, they're complete single-coil
IGN "systems". They contain ALL the electronics for dwell control,
current limiting, etc etc. These coils are DIRECTLY run from the
ECM/PCM. There is NO module. They have 4 terminals (plus the HV
terminal, that uses these ratchet style terminals I was tellin bout
yesterday), two for Bat Gnd, and Bat +12V, and the other two are the
digital EST signal and it's low-noise gnd return. Not usable for ION as
a transformer-type coil, cuz you cain't get to either the primary or
secondary on these puppies, but still a VERY elegant setup, indeed.
That ain't all. The biggest shock is yet to come. Brace yerself. They're
actually CHEAP (and nice and light, too). I couldn't believe it when I
went to check them out further. The GM parts counter LIST price is $41
for each "smart coil", and EVEN the harness for tying four of them
together is reasonable, list price of $62. You get 4 connectors for the
4 coils, and another larger connector. Not a bad price for 4 GM
connectors and pigtails (if you decided you couldn't use the harness as
is), at the very least, and you might even be able to get the bigger
connector from Packard! The shorty coil wires (yes, these DON'T squat
ontop the coils) have them real nice connectors I mentioned, and they as
well are pretty reasonable, at $11 ea list."

And

"I have nary a clue as to what an ICM is; never heard that before, unless
you mean just a "module". But these coils have all the electronics in
them to do the dwell compensation, etc., so they have NO module, but are
fired directly by a 5V logic level signal coming from the PCM. There is
NO separate system for just the IGN, the PCM controls all the IGN & EFI.
As far as a retrofit, not without some additional electronics. You need
at LEAST a crank wheel to fire these per-plug coils in pairs, and if you
really wanna fire only one plug at a time, then you HAVE to have a cam
reference as well. In addition to mere triggering, you'd need something
to model an advance curve, both the certifugal part that's rpm
dependent, and the vacuum part that's MAP dependent.
Rather than an older style dizzy based retrofit, I'd say these new GM
SmartCoils are more appropriate for someone who's gonna buy an
aftermarket ECU that's cabable of outputing spark trigger signals
directly, on a per-cyl basis. Then they'd be ideal, just one wire pair
from ECU to coil per cylinder, and poof coil/module DI system a done
deal."

Bob, I know these "Smartcoils" are available on the V8 Camaros.  You might
be able to find these in a wrecking yard.  You can also wire the two
triggers together, ala DIS.





> I know it is a bunch of work, but it keeps me out of the bars &
stimulates
> the mind.  I am running a 383, super ram, 700r4 & a 7730/8D.  check it
our
> if you'd like www.r71camaro.homestead.com
>

Surfed over to your webpage.  We are at opposite ends of the spectrum.
The engine in your camaro weighs as much as my '76 Porsche.  I couldn't
stop laughing at your puny rear brakes. :)  Me, I can stop on a dime, but
not much go juice.  That's one nice engine, though.  I also saw your old
VW toys.  That is my fun now.  Aircooled VWs and Porsches.


Good luck.  Let me know if you do the Smartcoil thing.  I am almost half
tempted to sell my RX-7 waste spark coils and just go with the Smartcoils.
They would be excellent for my small engine compartment, and since I'm
going to be running aftermarket engine management... ;)

Jay

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