Ignition Only

[Bruce Plecan]

> > 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 absolutely true for a 2 cylinder engine.
Also, would be firing at the same rate as a single coil, dissy.

Lets see a 6 cylinder distributor engine has 1 coil,
your saying that it uses 2 coils to fire 6 plugs, in a waste spark system,
hmm, gotta an example of that one.

The v-8 we'll just skip............

>A coil-per-cylinder setup pushes the limit
> even higher as a given coil has to fire only once every two revs, compared
> to 4 times per rev as on a V8 engine.

Assuming a 4 stroke,

> This helps maintain powerful sparks
> and decent plug gaps on high-speed, high compression engines, specially
> blown ones.

I may stand corrected on this but
I'd almost venture a guess MSD, and Crane could prove otherwise.
Since I don't know of any coil per plug CDs, where as there are CD DISs, or
in Crane's CD, you could use 3 on a 3 coil DIS waste spark, for CD DIS.
3 CDs on a 3 sets sets of DIS coils vs 6  Coil per Cylinder devises, at this
stage of the game I'd say the DIS would win handily.

Course we could get insane and go with a CD per coil per cylinder.  $1,400
just in hardware.

>It's probably somewhat cheaper too,

Let's see one module 4 coils vs
8 coils and eight drivers
Not in the above

>and it gives you total
> freedom on the spark timing, which can be important in some special cases,
> such as anti-turbo-lag systems in competition engines.

anti-turbo-lag
I switched parties I'm pro turbo excitement.
and leaning toward turbo-anti-lag
Bruce

 --Axel

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org