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#14055 - 01/12/05 12:45 PM ignition-electrical?
Anonymous
Unregistered


i've been playing around with the igniton on my 65 coronet. the original set-up was mopar electronic distributor, chrome box, blaster2 coil, and 1.25 ohm ballast resistor. anyhow, i've been talking to Don at FBO and decided to use some of his parts and ideas. i bought an electronic voltage regultor(works great), braided ground strap and one of his coils. all that works great. Don recommended a Standard ru-11 resistor rated at .25 ohms so i bought a couple(they were actually .5 ohms). the ru-11's run hot and glow on the backside, so i bought some mopar performance resistors that were rated at .25 ohms and were insulated on the back. i checked the resistance on all my ballast and the mopar had the least resistance but ru-11 put out 2 more volts to the coil. my question is; how can a higher resistance ballast put out more voltage to the coil?

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#14056 - 01/12/05 02:02 PM Re: ignition-electrical?
Anonymous
Unregistered


According to Ohm's law (Volts = Amps * Ohms, aka V=IR) the only way would be to increase the amperage moving through the circuit.

In reality, I would guess the RU-11 actually runs cooler than the MP unit fue to the lack of insulation on the back. The hotter any part of a circuit gets, the more resistance it has.

-SM

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#14057 - 01/12/05 02:28 PM Re: ignition-electrical?
Anonymous
Unregistered


Right. Heat = Resistance. It can pass more current, so it runs 'cooler'. What are the voltage requirements of your coil? Then adjust your ballast to that.

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#14058 - 01/12/05 03:18 PM Re: ignition-electrical?
Anonymous
Unregistered


i have an FBO coil. recommended voltage to the coil is 10-11 volts. the ru-11 .5 ohm gives me 8 volts, the mopar .25 ohm gives me 6 volts. i tested an MSD .8 ohm it was 7 volts to the coil. the stock 1.25 ohm was 5.5 volts to the coil.

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#14059 - 01/13/05 07:11 AM Re: ignition-electrical?
YO7_A66 Offline
master

Registered: 01/20/03
Posts: 5130
Loc: Indiana
If the recommended voltage to the FBO coil is 10-11v, how can we get this kind of voltage thru the aftermarket ballasts?
Can anyone that is running an actual FBO ballast confirm what your coil voltage is when the key in "on" & when the car is idling? (I blew up my actual FBO ballast so I can not test this, but I think that I remember mine showing 6+ volts when the key was at the "on" position.

I am in the same seat as gator. I have tested the 4 prong resistor to get 3.5v or 5.2v (pending on which side was tested) volts to the coil with key at the "on" position. I have tested the NAPA 1.25ohm resistor that gave me 5.3v at the "on" position, and now I have the MP 1/4 ohm ballast that gives me 6+ v at the "on" position and 8.5v to the coil with the engine idling.
Once again, can we get 10-11 volts at the FBO coil with the aftermarket ballasts? Do we need 10-11v at the coil?
BUMP


_________________________
1970 YO7 A66 [Canadian Export] F8 Challenger
340 (SL.P. 226/238@.050,270/288 dur,.538"/.528" w/Yella Terra 1.65 rockers, 9.7:1, 63cc Sidewinders (Bowl Ported),RPM intake, QF SS-750 Annular DP, MSD Street Fire Ign., & TTI's. 727/Dynamic 9.5" 3800, TF-2, & 3:91's

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#14060 - 01/13/05 07:24 AM Re: ignition-electrical?
Anonymous
Unregistered


Quote:

i have an FBO coil. recommended voltage to the coil is 10-11 volts. the ru-11 .5 ohm gives me 8 volts, the mopar .25 ohm gives me 6 volts. i tested an MSD .8 ohm it was 7 volts to the coil. the stock 1.25 ohm was 5.5 volts to the coil.




What if you ran two of the 0.25 Ohm resistors in parrallel? Then you'd split the load and should get 12VDC. Or is that too much?

Why don't they just make a 12-14VDC coil?

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#14061 - 01/13/05 07:39 AM Re: ignition-electrical? [Re: YO7_A66]
Anonymous
Unregistered


dave, how did you get 8+ volts with the .25 ohm mopar ballast? the best i could get was 6 volts. did you try the ru-11? i can get 8 volts with it, but it glows cherry red at the resister (no ceramic insulation on the back side, ). as far as running 2 resisters goes, i'm not sure if its practical or the right thing to do, just not that electrically savy.

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#14062 - 01/13/05 07:43 AM Re: ignition-electrical?
Anonymous
Unregistered


Practical schmacticle.

If the two parrallel resistors drop the right voltage and are not overloaded with current. Run it, until it breaks or you get the right ballast to go with that coil. Electricity doesn't know what it's doing, you have to make it work for you. Think of it as just another fluid your engine needs.
More voltage = more volume of electrical fluid.
More current = more electrical fluid pressure.
Get it flowing properly and how you did it won't matter.

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#14063 - 01/13/05 07:57 AM Re: ignition-electrical?
YO7_A66 Offline
master

Registered: 01/20/03
Posts: 5130
Loc: Indiana
Gator,
"dave, how did you get 8+ volts with the .25 ohm mopar ballast? the best i could get was 6 volts."

I don't know. I bolted it in and now I am getting 8.5 at idle & apx. 6.2 with the key on. I never checked the FBO ballast at idle though so I do not know if this is better or not.

I did not test the RU-11.

Edit:
Mine is part #2444641. It does not look like any of my other ballasts that I have bought from the local parts stores. The above part number has a metal bracket wrapped around it and it has two spades for the wiring along with two threaded studs too. Does this description match yours?





Edited by YO7_A66 (01/13/05 08:27 AM)
_________________________
1970 YO7 A66 [Canadian Export] F8 Challenger
340 (SL.P. 226/238@.050,270/288 dur,.538"/.528" w/Yella Terra 1.65 rockers, 9.7:1, 63cc Sidewinders (Bowl Ported),RPM intake, QF SS-750 Annular DP, MSD Street Fire Ign., & TTI's. 727/Dynamic 9.5" 3800, TF-2, & 3:91's

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#14064 - 01/13/05 08:34 AM Re: ignition-electrical? [Re: YO7_A66]
Anonymous
Unregistered


thats the same mopar resister i tested. it reads the .25 ohm on the multi tester, but doesn't seem to put the voltage out. i bought several so maybe i need to do some tests. if you get a chance test your ru-11 for voltage to the coil. it will have an ohm value stamped on one of the tangs. they do "glow" so don't let it lay on paint .

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