Which coils need/don't need the resistor wire w/ Duraspark

[kerb12]

The more I read, the more confused I get whether or not I should bypass the resistor wire on my '66 Mustang that I put a Duraspark II from a '78 Ford in. I have two coils I could use, one is an Accel "Duraspark Racing" coil and the other is an Echlin that I got from NAPA (also for a '78 Ford). The folks at Accel said I SHOULD bypass the resistor so I get full 12v to the coil if I use theirs. Does anyone know about the Echlin coils though? It says "12v" on it, but that's about it. I see people say that bypassing the resistor could burn up "stock" coils, but I don't know if that's referring to stock coils from the original year of the car when it had a points distributor, or stock coils from a car that already had a duraspark (like the '78 that I got mine from).

Has anyone come across a list of which commonly used coils need what?

 

[bubba22349]

Echline is NAPA's brand of parts I have used them for many years top quality. Accel at one time was made or owned by Echline, not certain but believe that company was sold off quite a few years ago to a major speed parts conglomerate.

It all Depends on your planed use but for a street DD type car I would likely go with the Echline coil would be about same as a stock DSII coil. If your building a more performance based or race car then use the Accel. To further confuse you some of the early DSII systems used a resistor wire, so you could try it with it won't hurt anything. You could also run a new wire easy enough to give you full 12 volts from your ignition switch. Also if you wanted use a toggle switch to change from one wire for street use (resistor) to the other (full voltage) for a little extra performance. Resistor wires were absolutely nessisary for the old point type systems to keep from burning up the points. You won't burn either of those coils by using full voltage. Good luck

 

[65coupei6]

I would just bypass the resistor wire and use an Accel Coil. They are not that expensive from most auto parts stores. Maybe $10-$15 more than a stock coil. If you do not want to remove the resistor wire then use it to trigger a relay.

Are you using a MSD 6 or regular control box?

 

[kerb12]

I'm using a stock control box, and this is just a daily driver but I'd still like to get as much performance out of it where I can. If I kept the resistor and that meant I was undervolting a coil that was expecting 12v, what would that mean? Would I just always have a weaker spark on the other side? Or would the coil still build up a high enough charge, just at a slower rate? Not sure how that works...

Eh, maybe I should just suck it up and rewire that part. All I need to do is pull out my ignition switch and disconnect the pink wire, and then run a new wire from the same spot on the switch through the firewall to + on my coil, right?

 

[kerb12]

What do you mean by using it to "trigger a relay"? Like adding a new relay somewhere under the hood, or could I somehow pull 12v from the starter relay?

 

[65coupei6]

Add a relay. Use the resistor wire to trigger it. Run a 12+ wire from the battery to the relay. The last wire is to the coil.

Just like this "Relay wiring diagram" : http://classicinlines.com/DUIinstall.asp

This way you don't have to mess with pulling out your ignition switch and cutting wires.

 

[kerb12]

Oh nice, I like that a lot. So after some reading, here's my plan:

Run a 12g wire from battery terminal on starter solenoid to 20a fuse to the relay. Ground the relay with 12g wire. Run the wire that's currently going to my coil (via resistor) to the relay. Run a 12g wire from switched power on relay to a terminal block, and then run a wire from that to the coil and also to the red wire of the duraspark module.

Seem right?