DeTomaso Mailing List: October 99, Message #1008

Isn't the ballast resistor only used to reduce the current/voltage at the
coil to reduce arcing on the points in the old-style distributors? The
ballast resistor is not needed for electronic distributor applications is
it? If so, I need to go to the store..

- Bill in Colorado


>
> Subject:  Re: Need quick help on MSD 2 "Blaster" coil.
>
> No, the idea of the resistor is that you deliberately design
> the coil to operate at a voltage lower than 12 V and then use
> the resistor to get to that voltage under normal conditions.
> When you're cranking the engine with the starter the battery
> voltage drops and hence the sparks get weaker. To combat this
> you bypass the resistor as long as the starter is operating.
> This gives you pretty much similar sparks during cranking and
> normal operation. It doesn't matter if you're running
> electronic or mechanical points, it works the same way for both.
>
> Tomas
>
> >>> "digiovanna@mindspring.com" 99-10-29 06:03:56 >>>
> My Mallory Unilite electronic distributor came with a ballast
> resistor and
> the instructions said to use it.  Why is this?  I thought the ballast
> resistors were intended to reduce the normal operating
> voltage that had to
> be switched by mechanical point gaps (increased life
> expectancy.)  This
> would appear to be unnecessary for electronic systems.  Is
> this Mallory's
> attempt to avoid secondary damage to retrofitted automotive
> systems?  Or is
> there indeed a need for the ballast resistor?  Seems like the
> whole idea of
> a high performance ignition system is to get the most spark
> energy, and this
> should be aided by increased coil voltage.
>
> -----Original Message-----
> From: Forest Goodhart <Forest-GoodhartÉHoffmancorp.com>
> To: Multiple recipients of list <detomasoÉrealbig.com>
> Date: Thursday, October 28, 1999 4:29 PM
> Subject: FW: Need quick help on MSD 2 "Blaster" coil.
>
>
> >
> >
> >-----Original Message-----
> >From: Forest Goodhart
> >Sent: Thursday, October 28, 1999 11:33 AM
> >To: Multiple recipients of list
> >Subject: RE: Need quick help on MSD 2 "Blaster" coil.
> >
> >Cal,
> >If you look closely at the existing dual resister you will
> find that one
> >side is in the lead from the ignition switch and the other
> side is in the
> >lead between the coil and the distributor. The ignition
> system is all Ford
> >so I don't know why they did this different than any stock
> Ford. The only
> >difference electrically is that the tach connection will see
> some different
> >resistance through the points. This puts the resistors in
> series and has
> >nothing to do with the starting system. I have not found a
> car yet in the
> >admittedly small number that I have worked on the used the
> starting circuit
> >bypass on the starter solenoid. If you were to add this
> bypass between the
> >solenoid and the coil then you would only be bypassing the
> first part of
> the
> >resister and maybe this is what you mean by the starting
> system. Whether
> you
> >need a resister or not is dependent on the ignition system
> you choose. Many
> >of the aftermarket systems still require a resister but some do not.
> >
> > -----Original Message-----
> > From: Eustaquio, Cal J ÄSMTP:cal.j.eustaquioÉlmco.comÅ
> ><mailto:ÄSMTP:cal.j.eustaquioÉlmco.comÅ>
> > Sent: Thursday, October 28, 1999 10:58 AM
> > To: Multiple recipients of list
> > Subject: Need quick help on MSD 2 "Blaster" coil.
> >
> > Hi All:
> > I'm in the process of ordering a small amount of items from Summit.
> >Just
> > wanted to know which coil to get. I intend on getting one of the
> >"ignition
> > management" 6A/6AL in the future and need any advice on this. The
> >reason why
> > I'm starting off with the coil is so that I can mount up the MSD
> >Blaster on
> > the bracket and put this away someplace. Additionally, I take it I
> >won't
> > need the resistor in this circuit anymore. I have a Motorcraft dual
> >resistor
> > assembly and understand that the other resistor is used in the
> >starter
> > system. Is there a single resistor assembly available someplace? How
> >about a
> > new Motorcraft dual resistor? I'd like to have new components for
> >the
> > bracket. Thanks. Cal #2428r. P.S. This is all an aside to the main
> >project.
> >
> >
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