Question full voltage?

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joshua dewitt

joshua dewitt

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I have a blaster 3 coil with factory 4 pin ballast resistor with an orange m/p ignition module and factory mopar electric distributor 1973 ( curved) ....
would like to have full voltage advantages with a c/d coil.... can this be safely wired in eliminating the resistor? or with out upgrading to msd or fbo module... stuck with a resistor in line for coil? anyone ever messed with this... wanted full 12.0volts at coil during cranking hotter spark all around.... what are your thoughts. 318 9.5- 10. c.r. guessing zero decked flat top pistons, with 302 high swirl port heads, bigger valves..
any thoughts????
 
You can take it out. The ignition box does not care about the ballast resistor being there if you have a 4-pin. The ignition box gets full voltage through it's normal wiring.

The resistor is there for the factory coil. It only drops voltage to the coil.
 
ok here is the other question, is it required to use the ohm resistor with orange box? or is the 4 pin too much? I just measured across top two reads 1.5 ohms bottom two across read 5.7 ohms... is this maybe why I was get a slow hard crank when warm?
is the blaster 3 coil too much? the car had an msd and craped out when back to mopar stand by,, and leaving it that way for a while..
 
so the factory coil long gone. had some universal Crapo on it when I got it. that means I can run my 50,000 volt c/d coil though the orange box and isn't going to cause any wire fires?
and If I under stand you gold dust.. I can completely remove it? or should I just and the single 2 pin ballast resistor, car far from stock. don't care.. want it to work well.
 
4 pin boxes don't need the dual ballast, it's not even connected. It connects to the 5th pin. If the 5th pin is not there physically, then only the single ballast would be needed even in a full stock system.

You will not burn the wires by taking out the resistor.

I was running a Wells stock replacement box with no resistor for a few years and it was just fine. I had a universal accel coil.
 
ok sounds good, I will go look at doing so. now ..I have a e-core c/d coil all ready rubber insolated on fender well read to be used, ok to use that one instead of blaster msd 3? the 4 pin connectors can just be all wired tighter then? and a one junction point?
 
If that coil didn't require a ballast, it should be fine. I don't really know much about those.

For the ballast connectors, the ones that went to the 5th pin can just be disconnected (use your ohm meter to find this), and then you connect the other two together with a jumper.
 
ok, as long as it doesn't hurt the ignition box, sounds right to me... I think it is only for the coil... and would love to get rid of it. I thought the resistor needed to be there for the module too. after doing some research I agree with you. will get to it later this week, I just fixed the horn and tuned the new summit racing carb a little, and installed new gas tank. today... no leaks so far!!!! Yea!!! have the new mopar performance blue wires coming an d will do that all when building them. by the way best known setting of timing with mild modified 318? with 340 mp cam? ball park for a starting point ?
 
I would start with 12-15 up front (whatever gives the fastest idle), and then limit the total timing to about 35 (this is with the vacuum advance unhooked)
 
67Dart273 said:
Well it might and people telling you otherwise ON A STREET DRIVE CAR are misinformed.
Click to expand...

And the reason for claiming this is?

The ignition box always has full battery voltage. The switching transistor does all the sinking. These were commonly known to be MJ10012's. [ame]http://www.nteinc.com/specs/original/MJ10012.pdf[/ame]

The power transistor can handle it. I doubt at the ignition box will have to sink more than 7A.

It's to protect the original style coils only. In a points system it was needed to keep from burning the points as well.
 
The blaster 3 coil has a primary resistance of 0.7 Ohms. With an estimated transistor collector to emitter saturation voltage of 2.5 V, the peak coil current will reach (13.8-2.5)/0.7 , that is about 16A. That exceeds the peak current of rating of 15A. Not good for coil nor ECM.
 
I had a CDI system on my car with an E-core coil. Ran pretty good. Then the computer crapped out.So I threw the ECU out, and had the E-core left over.
I tried that E-core with the standard Orange box ignition set up.I thought the car ran crappy compared to the CDI system. I did some research and IIRC discovered that E-cores work best with CDIs.So I installed the big square Accell Super-Coil, beside it.
Then I roadtested it for several weeks. Running first one for a week or two, and then the other; always verifying the timing at each switch.

The big Yellow Brick is still on the car, some 12or13 years later.I can't recall where the E-core is.
The Orange box is on the shelf looking for a new home. I replaced it with a Jacob's Opto-timer, soon after the Brick was settled on.
The Jacob's and the Brick do well together.Reliable sparking to over 7500.
I heard a rumor that you could weld with that Big Yellow Brick, but I wouldn't believe such nonsense.
 
KitCarlson said:
The blaster 3 coil has a primary resistance of 0.7 Ohms. With an estimated transistor collector to emitter saturation voltage of 2.5 V, the peak coil current will reach (13.8-2.5)/0.7 , that is about 16A. That exceeds the peak current of rating of 15A. Not good for coil nor ECM.
Click to expand...

Thank you Dave. I was about to estimate 20A. In any case, there are a lot of assumptions going on here. If someone wants to risk the price of an "orange box" far be it from me to stand in their way.
 
...........The chrome box on my race car over heats and craps out with0ut a ballast resistor....all it take is a 1/4 resistor to make it happy..............kim..........
 
67Dart273 said:
Thank you Dave. I was about to estimate 20A. In any case, there are a lot of assumptions going on here. If someone wants to risk the price of an "orange box" far be it from me to stand in their way.
Click to expand...

The current would be close to 20A if a modern IGBT is used. The MJ10012 is a Darlington, the second transistor in the configuration results in high gain to reduce the base current, but places a diode drop in the overall collector to emitter drop.

There are other problems, the 8mH inductance is large, resulting in greater spark energy. Exceeding the current, followed by a huge voltage, most likely will result in certain death to transistor. There is also power dissipation problem, because the heat sink is way too small.

What would likely survive is a heat sinked HEI module. The internal dwell control and current limit, controls the peak current to safe levels.

But...the blaster 3 is a miss match for an inductive ignition application.
 
the last 4 terminal (dual) ballast I checked had 1.6 ohms on the "coil" side (nominal is .5 ohms) and 6 ohms on the functioning 5th pin ECU "start" side (nominal ohms is 5 ohms) and I added a blue loop on the other end (so there is blue loops on both ends) to convert it to a parallel circuit & got 1.1 ohms which'll work fine with an orange box and an OE coil (& likely work well with your aftermarket coil also). the nominal ohms for the MP ballast for orange/chrome boxes is 1.25 ohms. You do have a fair amt of leeway on what you can get by with. (always carry spares tho!) but this was very close to OE dimentions & worked flawless. To the guys' credit there has been some VERY GOOD INFORMATIVE posted here in this thread!
 
Good info here and nobody is arguing yet... Way to go!!!
 
Rapid Robert said:
the last 4 terminal (dual) ballast I checked had 1.6 ohms on the "coil" side (nominal is .5 ohms) and 6 ohms on the functioning 5th pin ECU "start" side (nominal ohms is 5 ohms)
Click to expand...
It is very hard to measure <2 ohm accurately. With a standard 2-wire ohmmeter (most multimeters), always short the 2 leads to get the "lead resistance" and subtract. Laboratories use the better 4-wire "Kelvin method", which you find on some benchtop multimeters. Even then, you need to sand corrosion from the terminals. In addition, the ballast resistor's change resistance as they heat up (by design, to help limit coil current at low rpm). You also allude to the important issue of how the terminals and wiring adds series resistance. Those here who changed to an HEI module (GM, Pertronix II, ...) and an e-core coil just strive to get full BATT+ voltage wired to the module and coil, since the module regulates the coil current (as Kit stated). That was a late-1970's innovation, but the Mopar version was integral with the notorious "lean burn" spark boxes.
 
ok, now I'm questioning the factory wiring , if I go to the hei style e- core c/d coil... and wire directly to 12 volts +... not using the resistor will this short out my orange m/p control box? I was getting some ignition miss fire popping at higher rpm's with it wired in and using the blaster 3 coil...
 
Bypassing the ballast resistor will not "short out" your orange box. That is all on the upstream "supply side". To short it out, you would have to do something to connect its downstream "output" to ground. But, you don't appear to be reading the posts. Several mentioned that running a 1970's Mopar ignition w/ full 12 V may damage your ECU (orange box), but your car so welcome to try, just carry a spare ECU.
 
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