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Discussion Starter #1
so i got a msd blaster 2 coil. in the instructions it says i need a 0.8 ohm ballast resister. is this true or am i ok without it?
 

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Satyr of the Midwest
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Well, if it's this shape:



then you ABSOLUTELY need a ballast resistor. As long as it's close to 1 ohm, you'll be fine.

BTW, does your factory ignition system have a TFI module and a TFI coil? If so, this Blaster 2 coil would be a serious DOWNGRADE.
 

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Discussion Starter #3
im carb'd so im pretty shure they didnt put tfi on it.
 

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Discussion Starter #4
so no one realy know about aftermarket coils for us 80-86 guys and gals? what will happen if i just dont run the resister? or should i just go buy another crappy stock one?
 

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so no one realy know about aftermarket coils for us 80-86 guys and gals? what will happen if i just dont run the resister? or should i just go buy another crappy stock one?
What are you talking about? Sig just told you that you absolutely need the ballast resistor... without it, I'm not exactly sure what will happen, but that B2 coil won't last long and your truck won't run right.
 

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TFI coils (which take a full 12 volts) > Canister coils (which can't handle a full 12 volts, hence the need for the resistor)...
 

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Satyr of the Midwest
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It's not the voltage that will kill an oil-filled coil (yes, the old-style coils like that Blaster 2 are full of oil). It's the current. Excess current will literally cook the coil, causing the windings' enamel coating to melt, and then it basically becomes a huge brick of copper. Not good for your ignition switch or the rest of your electrical system, either.

The factory Ford TFI-IV system can develop a secondary voltage of 50kV (that's 50,000 volts), and it does so with NO ballast resistor. How? Well, there's no oil to cook, and dwell is better controlled, not to mention the better efficiency of the iron E-core design. Later TFI systems actually allow the PCM to control dwell instead of the TFI module. This is important because lowering the dwell lowers stress on ignition system components, particularly the ignition coil.

A Duraspark II/III system, which is the one that would use that Blaster 2 coil, can't develop that much; it's relegated to around the area of 30-40kV, and doesn't provide nearly the amount of spark energy while cranking as compared to the TFI. The accuracy of the Duraspark systems isn't as high as the TFI, either, meaning that where the rotor is in relation to the engine events and the subsequent electrical events aren't as accurate. TFI was indeed used with carbureted vehicles; one only need find the module bolted to the side of the distributor.
 

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Discussion Starter #9
thats seems alot better. thank u. i understand now that i need it. how come the accel coils dont even say anything about this
 

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thats seems alot better. thank u. i understand now that i need it. how come the accel coils dont even say anything about this
They may have an integrated resistor... Isn't that what the funky looking top is?
 

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Discussion Starter #12
u can run the coil with the msd box without the resister
 

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Satyr of the Midwest
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I have a blaster coil on my fairlane with no resistor and has worked for around 10 years.Stock duraspark dizzy running with MSD 6a box.Never any problems.Pulls good to 7500.
That's because it's a capacitive discharge (~440V to the coil primary) ignition, bearing little semblance to the original ignition. The coil's charge time is almost NIL compared to a factory Duraspark/TFI system.

As far as the Accel.... I'm not such a big fan of theirs, so with that, I can only conclude they want you to buy another one. :rofl: j/k I haven't any idea why they don't come out and say you need one.
 
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