[M] Alterpower alternator charging control switch

[Matt S Bower]

Glen Beard wrote:
> 
> 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


Your theory is good but the actual voltage is dtermined by the plug gap
and cylinder pressure.  By reducing the voltage you effectivly reduce
the output potential of the coil but rarely will anyone see voltages
that high if they have their ign. system in decent shape (ie correct gap
and good wires and cap and rotor.)  The high energy coils can usually
deliver more current but they usually will do this in a shorter amount
of time which can just amount to not allowing the time to get the fuel
burning, defeating the purpose.

My .02

Matt Bower