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Discussion Starter #1 (Edited)
as you guys know there is not very many coils list for our bike. actually none because accel only show the vn700 for the 140403 coil, but that is a no brainer. but this is my problem our stock coils have propietary wire and the accel set is about 170 dollars. I have been doing a lot of reading bored at work and came across a wonderful little thing called a ballast resistor that from what I have read will allow to use any coil you choose. so here is me thinking out side the box. why not look in to the automotive performance sector right? so this is what I am looking at, a mitsubishi 4 tower coil from msd that has a primary resistance of .51 ohms http://www.msdignition.com/Products/Coils/Stock_Replacement/8229_-_Mitsubishi_4_Tower_Coil.aspx
coupled with a 1.6 ohm ballast resistor from jegs on positive feed http://www.jegs.com/i/JEGS/555/40102/10002/-1. totalling the primary resistance at 2.11ohms.
I personally think it would make for a neat simple install with unlimited wire choices. let me know what you guys think.
 

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Discussion Starter #2 (Edited)
http://accel.zn1300.com/this is the site that got me curious if you guys would like to read towards the bottom under faqs were it talks about someone useing a buick regal coiuld pack on a kz1000
 

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That resistor would have to burn off about 52W in my estimation.
( 12V @ 2.11ohm = 5.69A and 5.69A X 1.6ohm = 9.1 V drop therefore 9.1V X 5.69A = 52W ) Also, wouldn't that leave the ignition coil seeing only 2.9V on its input ??
That's if I remember my circuits class :p
 

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Discussion Starter #5
the resistors are standard use in many coil application where it is neccesary to adjust your primary winding resistance to supply the correct load to ignition to prevent frying it.
 

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Discussion Starter #6
2.2 ohms is the primary resistance to our coil. so maybe that is the voltage they are really meant to run. alot of coils have the ballast built in so you do not need to add one externally. i just want to broden my choice of coils.
 

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It should work, if you figure out that whole resistance thing. My friend used an MSD coil on his EX500 (the one I have for parts now) and it ran pretty well for the time he had it. The coil was universal single output coil (used it on his Mustang I think)... for this bike we need two sparks fired at the same time, so either two coils with two outputs each like the stock ones, or four coils with a single output wired to be triggered in pairs... although I'm not 100% sure this would work if you split the trigger signal... it should, I just don't know for sure.
 

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Discussion Starter #8
the two coil i have link posted with have a power source and two triggers. Our bike has two triggers and a common power source just two twin tower coils, so there is no need to split the triggers.
 

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The Professor
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as you guys know there is not very many coils list for our bike. actually none because accel only show the vn700 for the 140403 coil, but that is a no brainer. but this is my problem our stock coils have propietary wire and the accel set is about 170 dollars. I have been doing a lot of reading bored at work and came across a wonderful little thing called a ballast resistor that from what I have read will allow to use any coil you choose. so here is me thinking out side the box. why not look in to the automotive performance sector right? so this is what I am looking at, a mitsubishi 4 tower coil from msd that has a primary resistance of .51 ohms http://www.msdignition.com/Products/Coils/Stock_Replacement/8229_-_Mitsubishi_4_Tower_Coil.aspx
coupled with a 1.6 ohm ballast resistor from jegs on positive feed http://www.jegs.com/i/JEGS/555/40102/10002/-1. totalling the primary resistance at 2.11ohms.
I personally think it would make for a neat simple install with unlimited wire choices. let me know what you guys think.
Our coils use a standard 7mm copper core wire that is easily replaced w/NGK caps, for less than $50.00 you will have NEW wires and caps. :beerchug:

Replacement wires and caps

http://motors.shop.ebay.com/lostnfound101/m.html?_nkw=vulcan+750&_sacat=&_odkw=&_osacat=0&bkBtn=&_trksid=p3911.m270.l1313


Dynatek DC4-1 Performance Coils

http://cgi.ebay.com/ebaymotors/Dynatek-Ignition-Coils-Coil-2-2-ohms-DC4-1-Dyna-CDI-/140448594663?pt=Motorcycles_Parts_Accessories&hash=item20b3637ae7
 

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Discussion Starter #10 (Edited)
I have a 100ft spool of 9mm msd super conductor and several high temp straight and 90 in my garage. I am mainly concerned about a cheaper better performing coil alternative that also provides a clean trick look. The msd coil is about 60 dollars compared to the dana 122 dollars.
 

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Discussion Starter #11
not to mention the plus of going to sealed water proof deutch connector vs. our crappy corosion prone blade connector.
 

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the resistors are standard use in many coil application where it is neccesary to adjust your primary winding resistance to supply the correct load to ignition to prevent frying it.
It's true that the ignition system wants to see a certain resistance, and too low a value would increase the Amps in the system.... possibly frying it...IIRC, the ballast resistor was used to drop the voltage to the coil. The coil was designed to run at, say, 9VDC nominal. That way, the ballast could be by-passed during engine starts, when the voltage drops due to the large demands of the starter motor.
My concern is that putting a resistor before the + terminal on a coil designed to run at 12V would drop your secondary output to an unusable level.
 

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That MSD coil is meant for CDI ignition, and our bikes do NOT have CDI ignition. With a suitable ballast resistor it perhaps / possibly / maybe might work, but why waste energy in the ballast when you could use that energy for the spark?

Since you are not looking for an exact replacement, why not buy two cheap coils like 380-086 from J&P Cycles. They are 3 ohm, but I bet they work better than the ballast/CDI coil you were planning to use.
 

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The Professor
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I have a 100ft spool of 9mm msd super conductor and several high temp straight and 90 in my garage. I am mainly concerned about a cheaper better performing coil alternative that also provides a clean trick look. The msd coil is about 60 dollars compared to the dana 122 dollars.
The Dyna's are $122.00 per pair, not each. :beerchug:
 

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Discussion Starter #16
Ok MSD techs got back with me today, and the say that the MSD 8239 coil would work with a 1ohm ballast resistor getting the primary resistance to within 10 percent of 1.6 ohms on the lower side of our ign req. They claim with subj ballast I would be seeing around 30,000 volts at the plugs during normal running and the full 36,000 volts during start up while the ballast is cold. So, since I lost the bid on the accel coils yesterday I am going for it and will post the results under my fat bob build if anyone else is interested in hearing the out come.
 

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I remember those damn ballast resistors on my Dodge Dart. Had to carry one in the glove compartment as they always burnt out. GM and Fords had a resistance wire. If I remember right it cut the coild volts to around 6 volts.
 

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Discussion Starter #18
for the added resistance i am thinking about trying to use a regular resistor to longevity of use since i do not believe starting will be an issue. from what I have read i will need a resistor capable of holding 240watts since i am using 12v at 20a. Is this correct me if i am wrong as i am not a electronic engineer i just know how to research. there are some resistors on ebay of that calliber in heatsinks that are about 2.5 inches long. it is pretty big but i have room.
 

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looks correct to me
 

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Discussion Starter #20
i think i am just going the have to use a blaast resistor and take one for a spare on the road. i am unshure of how reliable that are or how they do with vibration.
 
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