Ignition Only

[Bruce Plecan]

From: "Shannen Durphey" <shannen at grolen.com>

> Axel Rietschin wrote:

> > From: "Jurgen Hartwig" <jhartwig at midsouth.rr.com>
> > > Aside from simplicity and reliability, is there a measureable
> > > advantage to running DIS vs. just dizzy, assuming, of course, both are
> > > ECM controlled?
> > A wasted spark DIS doubles the rpm limit of the ignition system since
you
> > have twice the number of coils.

> This is not correct.  The max RPM for a distributor based system is
> higher provided sufficient firing voltage can be maintained.  The
> waste spark of the DIS system will cause problems in engines with
> exhaust/intake valve opening overlap as rpm increases.  The waste
> spark can fire the incoming intake charge at high rpm.  There are
> posts discussing this in the DIY_EFI archives.

But, in some applications you can use a 0 overlap cam, and avoid that.

> Distributor systems with 2 coils, which can alternate between coils
> for firing events can significantly increase available spark voltage
> at high rpm.

I also mention Yunicks 8 coil dissy but some where that got edited out since
it was a Distrubutor that violated some rule.
Bruce
>

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