Re: Ballast resistor & resistance wire, aftermarket ignitions

[jlandry@domain.elided (John A. Landry)]

As the putrid festering facial boil erupted, Doug Rasmussen
<76075.2276@domain.elided> yelled:

>  When I originally installed the Jacob's 2 years ago, I may have
>unknowingly shot myself in the foot.   I didn't realize the resistance wire
>existed, so of course I left it in the circuit.  I also regapped the plugs
>to the .055" gap recommended.  That gap may have been too wide considering
>the less than battery voltage I was inputting to the Jacob's.  
>
>  The resistance wire is still in place, it's just been bypassed.  I left
>it there to switch back to a stock coil ignition if the Jacob's ever bites
>the bullet.  I may do some input switching back and forth to verify my
>apparent performance increase.  This might be the incentive I need to buy
>an inductive pickup for my Fluke #97 scope to really see what's happening
>with the ignition.

Doug,

I don't own a Jacob's so I can't comment directly on how it's wired, but I
*do* have an MSD.  With the MSD, the wire coming from the ignition switch
merely acts to tell the ignition computer whether it's supposed to be on or
off.  The main power to run the ignition computer and drive the coil is
supplied from a separate heavy gauge wire connected (usually at the
recommendation of MSD) directly to the battery.  Therefore, MSD
specifically says the resistance wire and / or ballast resistor doesn't
matter.  The computer doesn't need a full 12 volts to know whether to be on
or off.  They tell you right in the instruction booklet that there is no
need whatsoever to remove or bypass the resistance wire or ballast
resistor.  As a matter of fact, it's better to leave it alone in case you
have to revert back to the stock ignition if the aftermarket computer
fails.

I'd be really surprised if Jacob's built their powerful ignition system to
get all of it's current through the original ignition hot wire.  Rather,
I'd take another close look at what you have... I just don't personally
know.  If your Jacob's ignition gets it's main power from a more direct
battery source, then any improvement in performance you got was either
imaginary or (more likely) as someone else implied (Tom H. I think) somehow
incidental to the changes you made.  Many many times folks rave about
performance gains they get by changing or modifying certain engine
components, but I contend that some large percentage of these perceived (or
real) improvements are caused by incidental mechanical repairs performed
during the upgrade.  For a fictional example, let's say a person is having
ignition problems traced to a weak or intermittent spark.  The stock coil
gets blamed and is replaced with some aftermarket high voltage racing job.
Performance is much better after, so the new coil gets all the praise.  But
what the owner failed to realize is that just cleaning the heavily oxidized
contacts between the primary wires and the coil terminals did the trick.
The stock coil could have been fine (it wasn't tested of course), but no
one will ever know.

My point is that regular and *detailed* preventive maintenance is usually
overlooked on most vehicles.  Older vehicles require a lot of preventive
maintenance to remain at peak performance.  Usually people turn to quick
and glamorous fixes to try and boost performance back to something they
remember from their past.  "Upgrades," in many cases, act to mask, coverup
and compensate for poor maintenance practices.  Aftermarket ignitions are a
prime example.  Don't get me wrong though...  aftermarket ignition systems
do offer some improvements.

Then also... one's perception of an improvement can also be vary deceiving.
Doesn't your truck just seem to run smoother and better after being washed
and waxed?  Mine sure as heck does!

Sorry for the rambling... I'm trying to fill in for Tom M. and John H.
while they're gone from the list.

John
NOTE: To reply, replace "mouse-potato" with "halcyon" in e-mail address!
-------------------------------------------------------------------------- 
jlandry AT halcyon DOT com       |   I want to know the TRUTH about our
Conservative Libertarian         |     government's secret operations.
Life Member of the NRA           |
WA Arms Collectors               | That's why I watch the X-Files on FOX! 
Commercial Helicopter - Inst.    |
http://www.halcyon.com/jlandry/  | 1976 Scout II Traveler "Patriot" model