I have always been skeptical of the claims that Jacobs make in their
advertising. I personally put a lot of it in the same catagory as Slick 50
and the Fuel Cat. They may have some effect but they are not overly
beneficaial.
Jacobs talks about tailoring the spark to the needs of the cylinder. A
spark has to be in the right place at the right time. It has to be strong
enough to cause ignition. Since Jacobs ignition systems can't change the
position of the spark- your sparkplug is still in the same place- and it
does not change the engine timing to my knowlege, it must be varying the
strength of the spark or, like multispark systems, be adding extra spark
events after the initial ignition.
In my opinion there is one rule that applies to optimizing spark- more is
better. The hotter the spark, the wider the gap, the longer the spark
duration, and the more redundant spark events provided, the more likely it
is that the fuel air mixture will be reliably and repeatedly ignited.
Therefore, optimizing the spark output for specific engine conditions is a
bunch of horse pucky as far as I can tell.
There are limits to this approach. You don't want one part of your
ignition system overpowering another part such as using a capacative
discharge system or super hight output coil with points since you could
destroy them in a matter of hours. Also, reducing the spark plug wire
resistance below a few K-ohms is probably not worth it in performance terms
considering the havoc created to local radio and TV reception. I would
consider anything under 10k-ohms to be acceptable.
Another area where you have to be careful is letting the multispark
continue past the completed power cycle and into the exhaust stroke. This
doesn't really hurt anything but is is a waste of energy and I suppose it
could cause a backfire in rare circumstances. I suppose you could consider
changing the amount of time for multispark after initial ignition with
engine speed to be tailoring the ignition performance to the needs of the
engine but all multispark ignitions do this.
Jacobs also claims to use newer technology than MSD. This may or may not
be true but technology in itself will not give better performance. If the
technology impacts one of the variables then it would be a benifit but
Jacobs never makes a specific claim for better performance.
I had an MSD system on a Chrysler 440 once and it did give a more reliable
idle with the performance camshaft. It also seemed to bog less off the
line with sudden throttle openings. Other than that I couldn't say that it
was an improvent.
I also used Bosch Platinum plugs for a time in my cars. I can't say that
they ran any better but they do last longer. Provided that your car
doesn't ruin plugs by oil foulin or rich mixture fouling, they are a nice
"don't have to worry about that" kind of addition.
If I were buying a high performance ignition system, I would probably buy
the Crane Hi-six system. I think that it looks like the best compromise
between price and benefits. However, it won't work with positive ground
and point so I will have to pass for now.
As alway my opinions (just like armpits, everyone has a couple and most of
them stink) YMMV, I make no money off this.
Regards
Bill Eastman
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