Came across this answer in another forum... a guy was asking which one
out of a lineup of four fancy high output coils would be the best for him...
Look here's the deal. Back in the day of conventional ignition systems coils
came in two flavors, ones that were designed for an external ballast resistor,
and those that had the ballast resistor built in. The ballast resistor was there
to limit the current to the points so that they had a chance to last 12,000 miles.
So what's the deal with high performance coils?
Well if we were to put your '66 Muchwang on an ignition scope we would see
that the secondary voltage is about 9-11KV at idle. If we then screw one of
these super coils on the car and re-scope it. What do you think we will see
for secondary voltage at idle? If you guessed 45KV you would be wrong. If you
guesses 9-11KV you would be right. Why is that? The coil is only going to
produce enough voltage to ionize the gap in the spark plug. No more.
Now under some other conditions the coil will need to produce more voltage
(typically during a hard acceleration) but very rarely will a coil need to produce
more than 20KV on a conventional system.
So yeah... you saved yourself some coin by not buying that "racing" coil. There
is no need for anything better than a factory coil, unless you have some serious
modifications going on... like a 30psi turbo build
Cheers... jondee86
