"The Importance of the Capacitor"
Without a doubt, the MSD Ignition is the most
successful Ignition ever. The same units used by teams in NASCAR and
the NHRA are available for use on the streets. Fortunately, you don't
have to have a race car or be an expert installer to install one. While
the installation is very simple, there are still several little "tricks
of the trade" that can help the install go a little easier and add a
little life to the system.
Mounting the MSD:
While you will often hear that you must mount the unit in an absolutely
dry place, a little splash of water is perfectly fine. I'm not saying
that you want to put it where it will be regularly hit by water; most
under hood locations will be fine. Even hitting it with the hose while
washing under the hood won't be a problem, so put it where it will look
and fit best. All this being said, avoid mounting the unit
up-side-down. This will prevent it from filling up with water, which
could be a potiential problem. Normally, any water that does enter the
unit will drain out of the bottom - which is why it isn't "sealed" to
the rest of the case.
The one thing that you do want to avoid is excessive heat. Mild radiant
heat isn't a problem, but putting it right over a set of headers is not
going to be a good idea. So as long as you mount the unit in a
reasonable location, and in a reasonable position, anything else goes.
Wiring it up:
Hooking up an MSD is really very simple. The large red wire goes to the
battery (after going to a capacitor first), and the large black wire
goes to ground. The small red wire goes to ignition (+12 volts with the
key on), and the small white wire goes to points (the wire that used to
trigger the coil). The remaining two wires, orange and black, will go
to the coils positive and negitive terminals. Make sure that nothing
else is connected to either the orange or black wires but the coil.
Also, make sure that any wires that get extended have at least the same
size or larger wire used. If the MSD is installed under the hood (near
its battery connection) it isn't necessary to use a fuse. If you will
be installing it in any location that requires you to entend the length
of the wire, you should add either a fuse or a
circuit breaker.
Adding a Capacitor:
Here's the part you may have heard of, but never paid much attention
to. Adding a capacitor when installing an MSD offers several advantages
and is very benificial to a long lasting ignition. MSD calls it a
"Noise Filter," but it is simply just a cap. Typically, these are used
to help filter out any radiated noise from the ignition to your
electrical system which can cause some radiated noise through your
stereo. For most of us this won't be a problem. The important thing is
that this cap also filters the power going to the
MSD. This will prevent power surges and spikes from damaging the MSD.
Things like jump-starting your car are very tough on sensitive parts,
but using a cap will provide the protection you need.
At this point, you have the option of either ordering the MSD part (PN
8830), which is what I recommend, or going to your local electronics
part store and picking one up. If you do the latter, you will need one
of at least 25,000 microferrad and 16 volts. Anything bigger will be
fine, but any larger than 50,000 microferrads will simply be overkill.
Just make sure that it's at least 16 volts and not just a 12 volt cap.
To install the cap, simply run the power lead for the MSD to the
positive terminal of the cap. Then run a wire from this same terminal
on the cap over to the battery. At this point you have two options: You
can either run the negitive lead from the MSD much the same way - to
the cap and then to ground, or you can simply
ground the MSD and then ground the cap - independently. (Both methods
are shown below) Either way will work just as well, just go with
whatever install method you think will fit your install best.
Understand that adding the cap may be the one thing that makes the
differance between an ignition that lasts the life of the car -vs- one
that only lasts to the end of the year. After having installed around a
hundred of these Ignitions, I can assure you it really does make all
the difference. The only two I've ever seen go bad, didn't have a cap
installed.
More options:
There are so many things you can do with an MSD, make sure that you
take advantage of some of its flexibility. Some of the options are
multi-stage rev limiters, timing controls, shift lights, etc... Many of
these things are designed to work in conjunction with other
non-ignition related items, such as Nitrous, Superchargers, Line Locks,
Drag Racing, etc... The thing here is to not limit yourself. A good
ignition system is much like a good alarm. It should do more than just
the basics. The same way the alarm should lock and unlock your doors,
your ignition should do all it can.