(another) Duraspark II question

[Anonymous]

I have read the other duraspark threads and still am not sure of the answer to my question.

I will be upgrading to a DSII this weekend and need to know about the wiring. I will be using a GM module and have the wiring digram. I am running a universal 12v coil from jegs, with this coil should I

A.
Replace the resistor wire from the ignition switch to the coil with a regular wire to put 12v to + side the coil and then on to the GM module from there, getting rid of the wire from the I terminal of the solenoid to the coil.

Or B.
Run a new wire from the S terminal of the solenoid to the module and leave the wiring to the coil alone.

Thanks in advance
Eddie.

 

[Lazy JW]

It is best to run a coil at its rated voltage. Not knowing what voltage your coil is designed for it is difficult to make a recommendation.

HOWEVER, I see no sense in running a breakerless ignition system on reduced voltage like Ford did with the DS2. Since you have no points to burn (really the limiting factor) why not use full voltage?

An ignition coil is really just a transformer. It "steps up" low voltage current to high voltage current. The laws of physics also dictate that when you step the voltage up, the current goes down proportionately. You cannot avoid this. And it really is the current (measured in joules) that does the work of igniting the fuel.

There is much advertising hype about "High Voltage" coils. If this high voltage is obtained by using the same reduced voltage(less than 12 volts) input, then the current HAS TO BE REDUCED. As long as the voltage is sufficient to jump the gap, then we really want the current to be as high as possible. This CANNOT be done with a "high voltage" coil operating at reduced input voltage.

You have made a good choice in the DS2/HEI setup. If it were mine I would verify the voltage rating of the coil and run it on full voltage regardless And I would start looking for a TFI or HEI coil.
Joe

PS. I would wire it according to your choice "A".

 

[Anonymous]

I wonder -why the GM module? I put the ford box in mine ,seems to work great -price new--$16. went to the junkyard and got the piece of harness to plug it in with for $5. No wire spliceing -install time maybe 4-5 minutes.

 

[MustangSix]

The GM module is very small and the wiring is less intimidating for most. Most importantly, it is small. And it has the advantage of being smaller than the Ford module. And since it is small, you can hide it. Because it is small. And not large, like some modules. And those are the major advantages......

 

[wallaka]

So lemme get this straight, it's small, right?

 

[Anonymous]

smaller IS better

 

[MustangSix]

And I forgot to mention,

cheep...

 

[addo]

I have been told straight up by GM people that the aftermarket (and newer GM) modules are not as good as the old ones, in terms of being less long-lived and reliable. Suppose the caveat then, is to get an NOS unit.

Besides that, I thought the upgrade was the Delco module plus a Ford TFI coil!

Regards, Adam.

 

[Lazy JW]

The GM HEI module was designed to be used with the (surprise!) HEI coil. Which Ford copied pretty much verbatim when they finally admitted that the DS2 coil really wasn't much different than the breaker point coil that it replaced. The DS2 module wasn't designed to run the TFI/HEI type coils, which draw considerably more amps, although some folks have used the TFI coil on the DS2 module successfully. Having personally fried several DS2 modules on different vehicles, I just don't trust them for even stock use. So when I learned about the GM HEI conversion I jumped right on it. Works fine, lasts long time
Joe

 

[Anonymous]

So..... if you already have a DS II setup (module, distributor, coil) and it works fine, what would you have to do to convert? Did I miss something somewhere in a past post about how to wire this setup? I ended up using a solenoid to send regular voltage to the module on startup, then it switched back through the resistor wire for run mode.

 

[Lazy JW]

I got my wiring diagram at www.gofastforless.com
I posted some pictures on a thread in the Big Six forum but don't know how to link to it.
Joe

 

[Anonymous]

Thanks for the answer JW, very clear and helpfull. The coil was advertised as a 12v coil so that should work.

Eddie.

(I will be using a computer processor heatsink to cool the module, I'm not sure if anyone has done that but I figure is should be pretty effective.)

 

[addo]

Don't forget a little of that silicon heatsink grease.

 

[Anonymous]

yup, got that. What guage wire is best for wiring up the module?