[M] Alterpower alternator charging control switch

Glen Beard gbeard1 at nycap.rr.com
Fri Mar 12 06:28:43 GMT 1999


KD6JDJ at aol.com wrote:

>   Then if we are considering that the battery is charged, as stated, the power
> consumed by the alternator should be way under a hp.

Doesn't the alternator keep the system voltage a little higher than 12.0vdc?  This
may just be my gauge inaccuracy, but my dash voltmeter reads around 13.5vdc when
I'm not at idle.  What I'm thinking is if you disconnect the alt at WOT to remove
that extra little load, won't you effectively lower your spark voltage?

N1/V1=N2/V2
N1=# of windings on your primary coil
V1=voltage on pri coil
N2=# of windings on secondary coil
V2=voltage on sec coil

Lets say for example I am putting 50kV across my spark plug right now at 13.5vdc.
That gives me about a 1:3700 step up transformer.

If I lower the pri voltage to 12.0vdc (battery alone) this would give me 44.4kV
across the plug.

I don't know how to estimate the current through an arc, so I won't go into the
change in current, but if you assume a constant resistance you can see that by
lowering your spark voltage, you will lower the current.  That in turn lowers that
temp of the spark which will lower the completeness of the burn in the cylinder.

I might be nit picking a very small difference, but I do know that allot of
aftermarket companies make high energy coils and capacitive discharge ignition
systems all to raise the spark voltage.  Ever wonder why they make those 8.5mm low
impedance park plug wires??

--
Glen Beard
95 T/A conv M6 Vortech  !heads, !cam
http://home.nycap.rr.com/gbeard1/TransAm.html





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