Igniters => DIS

[Jurgen Hartwig]

> I have been working on my little DIS project & am counting on the coil
> charging for a maximum of 3/4 of a rev of the crank.  this being the
case @
> idle the circuit would have the longest "on" time @ 23.1 mS @ 650 RPM, &
the
> shortest time of 1.5 mS @ 10K RPM (yea like my stroker is going to get
to
> 10K, God I hope not or I will put small bits of stroker all over the
road).
> think that this would be too long @ idle?  I am going to mock it up with
> LED's @ first & the plug the coils in later & see what happens.
>

Bob, in two pieces of literature I have (Ford FI manual and Wolf 3D
manual), coil dwell, or charge time, is between 4ms and 6.5ms.  I believe
those are constant dwell times, and if that is true, then 23.1 ms is
probably too much.  There is a Motorola chip that controls dwell.
However, I forget the number.  I can try to find it if you would like, but
to be honest, fabricating all this sounds like a lot of time.

>
> if this does happen to be too long a charge time then maybe I will give
> James a ring & see if I cant get some of those smart igniters from him &
> skip the IGBT all together.  I would much rather pay the $4 each than
$30
> each for igniters though.  specially if I goto CNP ($30 X 8 = too much)
>

Bob, if memory serves, those CNP setups already have igniters on board.
$240 for CNP, or $20 * 4 for GM coils + $30 * 4 for smart igniters.  If
you check the archives (1999) somebody (Gar or Bruce or perhaps Shannen)
had done a writeup about CNP.  I can't remember if they are TTL.  If so,
they might be your cheapest route.  I can't remember what setup you were
running (what fuel injection system?  Aftermarket or OE?)

Jay

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