Current or Voltage Ignition - Dodge Dakota Forum

Subject: Current or Voltage Ignition
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Alright heres one for the engine buffs.... In the 360 motor family (318, 340, 360), do the motors prefer higher voltage, or stronger current in the ignitions?

DanK
Dodge Dakota
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8/15/2005
01:05:44

RE: Current or Voltage Ignition
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In ANY motor using a simple coil ignition:

Power in = power out, minus a small bit from resistance, inductance, hysteresis and counter EMF losses.

Assume a pulse of 12V at 5 Amps to the primary.
Power in Watts = Voltage x current.
12V x 5A = 60 Watts
Assuming no losses whatever in this simple coil:
If secondary voltage output is 30,000V, then secondary current output is 0.002 Amps (or 2 milliamps), because the Power of the output pulse cannot be more than the 60 Watts that was put into the primary.
30,000 x .002 = 60.

satakieli
Dodge Dakota
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8/15/2005
13:55:26

RE: Current or Voltage Ignition
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Yes this is what i know already. however what im trying to get at is how the magnum engines favor ignition in ultra high perfromance, not how ignition works. Ive been trying to tune my 360 motor for a few weeks and am trying to get the most power out of it. Some engines respond better to voltage and some better to current. Im trying to find the best for this engine

JoeX
Dodge Dakota
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8/15/2005
15:06:55

RE: Current or Voltage Ignition
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And ALL engines will respond better to proper ignition timing!
All the voltage or current in the world won't help a poorly timed engine.

actually
Dodge Dakota
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8/17/2005
18:55:15

RE: Current or Voltage Ignition
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I don't know if any of you noticed but there volt meter in your trucks ALL read a higher voltage the colder it gets outside, so take a hint. however, too much voltage or amperage fries the PCM and too low, under 10.5 volts or so and the whole thing quits. lights and radio work but the engine stops dead.

JoeX
Dodge Dakota
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8/17/2005
20:49:51

RE: Current or Voltage Ignition
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The charging system is turned on and off with the ignition switch. The system is on when the engine is running and the ASD relay is energized. When the ASD relay is on, voltage is supplied to the ASD relay sense circuit at the PCM. This voltage is connected through the PCM and supplied to one of the generator field terminals (Gen. Source +) at the back of the generator.
The amount of DC current produced by the generator is controlled by the EVR (field control) circuitry contained within the PCM. This circuitry is connected in series with the second rotor field terminal and ground.
A battery temperature sensor, located in the battery tray housing, is used to sense battery temperature. This temperature data, along with data from monitored line voltage, is used by the PCM to vary the battery charging rate. This is done by cycling the ground path to control the strength of the rotor magnetic field. The PCM then compensates and regulates generator current output accordingly.
All vehicles are equipped with On-Board Diagnostics (OBD). All OBD-sensed systems, including EVR (field control) circuitry, are monitored by the PCM. Each monitored circuit is assigned a Diagnostic Trouble Code (DTC). The PCM will store a DTC in electronic memory for certain failures it detects. The Check Gauges Lamp (if equipped) monitors: charging system voltage, engine coolant temperature and engine oil pressure. If an extreme condition is indicated, the lamp will be illuminated. This is done as reminder to check the three gauges. The signal to activate the lamp is sent via the CCD bus circuits.

Satakieli
Dodge Dakota
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8/18/2005
15:55:47

RE: Current or Voltage Ignition
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Ignition as in secodary ignition!!!!! Not on primary ignition, how it works or what it does do a computer! what i am inquiring about is in an AFTERMARKET IGNITION SYSTEM what does the engine prefer? holy crap i feel like im in college again at my auto instructers mercy

Kowalski
GenIII

8/18/2005
16:08:24

RE: Current or Voltage Ignition
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I feel your pain - you're asking specifically about current to your coil and what kind of coil to run, and these guys just aren't getting that. Unfortunately I don't know the answer. As a side note to Joe X, its not true that all vehicles have OBD - I've owned many, and still own one that doesn't.

Lead, follow, or get out of the way

jj
Dodge Dakota
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8/19/2005
00:52:32

RE: Current or Voltage Ignition
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As a rule, most Chry. tend to prefer a long duration spark with lots of energy.
You really can't seperate voltage and current as they are related. Except on the primary side.
So the system with the most joules at the rpm range you need is your best.
I am assuming you want to know whether to stay with an inductive discharge (primary high current) or go to a capacitive discharge (primary high voltage). Correct?
You need a certain voltage to jump the gap, after that the system that gives the most joules per spark will usually give the best performance.

All in all, I don't know the answer but I am running a MSD 6AL if it helps :)

JoeX
Dodge Dakota
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8/19/2005
23:46:34

RE: Current or Voltage Ignition
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Oh. What kind of coil to run.
If only he'd asked that question a little more directly.

Sorry.

hmmm
Dodge Dakota
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8/20/2005
07:22:18