Can i use (2) MSD single coils to replace OEM?

Matt_E

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The OEM coil is not "2 coils in one".
It's simply a regular coil with two secondary terminals.
Every time it fires, both plugs fire.
 

Waternut

Customizing addict
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Macon, GA
I also wondered this. What would prevent 2 coils from functioning the same? You have 2 wires going to the regular coil with 2 studs. If you spliced 2 wires into each main wire going to a regular coil, couldn't you then run 2 seperate single coils?
 

Matt_E

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I also wondered this. What would prevent 2 coils from functioning the same? You have 2 wires going to the regular coil with 2 studs. If you spliced 2 wires into each main wire going to a regular coil, couldn't you then run 2 seperate single coils?
It's not two coils!
Why would you want to run 2 coils instead of one? Both fire at the same time.

Is it worth risking the integrity of your TL brain to try it? Noooooooooooot for me
The OP is inquiring about using two TL coils in place of an OEM coil, not vice versa.

Besides, it is well known that you can indeed use the OEM coil instead of the TL coils for a TL system.
A coil isn't going to fry your TL. The dump into the coil is a short circuit anyhow. You can't make that any worse - it's designed that way.
 
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Kennay

Squarenose for the _____
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Myrtle Beach, SC
It's not two coils!
Why would you want to run 2 coils instead of one? Both fire at the same time.

The OP is inquiring about using two TL coils in place of an OEM coil, not vice versa.

Besides, it is well known that you can indeed use the OEM coil instead of the TL coils for a TL system.
A coil isn't going to fry your TL. The dump into the coil is a short circuit anyhow. You can't make that any worse - it's designed that way.


Dude, SLOW DOWN. The single channel total loss system that JFW and I have are single channel systems. Using two tower coils even on a single channel total loss would be the same as trying to use it on an oem system in the sense that the oem and TL single channel coils work in the same manner regarding plug firing; They both fire at the same time.

And regarding messing up the total loss as a result of wrong coils... I wouldn't chance it. It's not worth it, especially considering that an OEM coil or a blaster coil are cheaper than a pair of tower coils to try out. :sneaky:
 

Matt_E

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We are saying the same thing: For a single channel ignition (older TL, OEM) it would be stupid and chancy to use two coils.
Why would anyone want to do that? :confused:

Two single tower coils = two coils
Twin tower coil, OEM coil = single coil.

And you'll note that I didn't say to try and run two single tower coils: I said you can run the OEM coil on single channel (and even dual channel) systems.
Not vice versa.
 
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Waternut

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I certainly wasn't saying I'm about to do it. I've spent enough time and money this season... just thought I'd share my thoughts on the matter and possibly a way to make it work.
 

Matt_E

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I wouldn't.
The single channel brain is designed to drive only one coil, and fires every revolution (both plugs at once).
Hooking up two coils doubles the load and lowers the output voltage.
 
but if the primamry circuit of the coil is almost a dead short, how would hooking up 2 primaries hurt anything?

and why wouldnt they spark?

i have thought of this too, but for no reason other than mentalmasturbation.
 

#ZERO

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The load on the circuit will probably be fine but coils have different rise and fall times at different temperatures and this will cause one coils to work inconsistently from one another.

If you're going to use two coils you need to have two different primary circuits for them to function correctly.
 

Matt_E

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but if the primamry circuit of the coil is almost a dead short, how would hooking up 2 primaries hurt anything?

and why wouldnt they spark?

i have thought of this too, but for no reason other than mentalmasturbation.

It is almost a dead short - however, by hooking up two coils in parallel, the resistance halves, doubling the current draw.
The voltage transient will look much weaker and different than with the proper load on the circuit.
The energy available to the circuit (V*I*t), area under the voltage-current curve, will be much smaller than intended.
 

Philip Clemmons

Owner, P&P Performance
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Richmond, Va
It is almost a dead short - however, by hooking up two coils in parallel, the resistance halves, doubling the current draw.
The voltage transient will look much weaker and different than with the proper load on the circuit.
The energy available to the circuit (V*I*t), area under the voltage-current curve, will be much smaller than intended.

I agree with Matt...............

Some more info:
Coil impedance cannot be measured with a meter, but resistance can. The difference is that impedance is dynamic, and resistance static. Each time the primary coil is energized, a magnetic field is created around the coil (hence how relays and solenoids work). Each time (off time) it is not firing, this magnetic field collapses and induces a magnetic field back into the coil's primary winding (ALSO CALLED "BACK EMF"). This increases the impedance, and alters (SLOWS DOWN) current flow. Since there is no magnetic field when you measure the resistance, it shows almost a dead short, and resistance very close to 0, such as .3 ohms.............If you use Ohm's law to calculate (Amps=Volts/Resistance), you come up with 40 amps draw........This is clearly not the case. The factory 14-16 ga wires would melt with that kind of load. The back EMF caused by the collapsing magnetic field adds resistance that is not measurable with a meter, thus reducing the actual current draw.

BOTTOM LINE-wiring two coils in place of one could have a lower impedance, and as Matt said, higher current draw, which could damage your ignition. Not a good idea.

Its the same as hooking up more subs to the same car audio amp-power will go up because resistance (and impedance) has decreased, but the amp is working harder and will overheat and burn up..........
 
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Matt_E

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You're half-way there. The timing of the voltage transient (spark!) would be different, too.
Hooking up two coils in parallel cuts the inductance in half (assuming both coils are equal) which changes the time constant of the circuit.
The spark would not only be weaker in energy terms, but the timing would be off, too. (I think it would be shorter duration).
 
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