Is there a better, more powerful coil for MSD systems than the High Vibration coil? I see they have one model called HVC that is epoxy potted and is double the cost. Never really heard much talk about this.

Good question!
Steve

Have one of those HVCs on my car, throws a spark like an arc welder!

I'd like to know too.

theory says that you only need enough spark to overcome the potential and the conditions that exist i.e cylinder pressure, mixture etc. the dyno proves this is true. arc welder coils are, like so much of this other stuff just voodoo and shiny beads and trinkets. if your motor is conventional... i.e normally aspirated, less than 13 to one CR, and running on pump gas of some sort then the coil you buy at napa for 16 bucks is every bit as good as the best piece of garbage that MSD makes from an electrical standpoint of running your motor.

structurally is a different deal. if you have a harmonic issue such that you are vibrating the insides to bits somehow, then a solid potted transformer type will be a better solution.

I had my MSD box rebuilt and the guy that did it suggested a coil from Auto Zone. I am running that coil and did not see any problems with it on the dyno..

there is always the presumption that the consumer know what he's doing/buying , however. internal resistance of the coil is a key component in the slection process. points coils are not the same internal resistance as coils for transistor ignitions and not all transistor ignitions use the same type of coil. put a transistor "spec" coil on a points set up and the spark will be weak. put a points coil on a transistor set up and it will often burn the amplifier, especially if you leave the ignition on w/ out the motor running...

each ignition type and each transistor ignition will have its own requirement for coil internal resistance which is on the sheet of paper that was in the box when you bought it and you threw away without reading it.

Use the HVC coil and box in the race boat...great product

I've used several different brands of ignition box with the matched recommended coil, never had a problem, never noticed a difference between them. For me, it didn't make much sense to run a cheap coil with a high dollar box and expect it to work right.

I've used the Jacobs ultra coil for 12 seasons now with no problems . The H.P. fires as soon as i touch the key .