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914World.com _ 914World Garage _ coil resistor

Posted by: MarkG Dec 27 2004, 10:13 AM

Turns out my Jacobs coil does NOT have an internal resistor which explains my point melt down probelm....

Anyone have any idea what resistance ballast I need or how to calculate resistance needed?

Or should i just get a Bosch Blue..........?

Posted by: Brando Dec 27 2004, 10:37 AM

It'd be easier to just get a bosch blue, imho.

Posted by: MarkG Dec 27 2004, 10:41 AM

Me thinks you are right. It will be my lunch hour journey.

Posted by: BMartin914 Dec 27 2004, 11:18 AM

IMHO...I would go with the Bosch Blue and a Pertronix Ignitor and eliminate those points altogether.

I wish you luck in getting your car roadworthy Mark!

Posted by: carepro914 Dec 27 2004, 04:13 PM

I have a MSD Coil and Electronic pick-up in my 73 2.0 litre 914. I had to put a ceramic resister in line to cut the power to the points. You was able to find 1 of those at the local auto parts store.... not from 1 of the young guys working the counter, but an older guy that knows them from the use on small block Chevy V8's. My pickup had a max amount of power it took. A resistor will stip down 100% of volts to a 50% etc.... so that's what you got to look for.

The Bosch Blue Coil was always hot and my car didn't fire off real easy. After putting in the MSD coil, I had not problems.

Posted by: Aaron Cox Dec 27 2004, 04:22 PM

coils should have a 3ohm impedence correct?

Posted by: Mueller Dec 27 2004, 04:39 PM

QUOTE (Aaron Cox @ Dec 27 2004, 03:22 PM)
coils should have a 3ohm impedence correct?

each manufacture is different...my Accel coil is 1.5ohms, not too sure what the Bosch coils spec out at???

Posted by: Aaron Cox Dec 27 2004, 04:41 PM

QUOTE (Mueller @ Dec 27 2004, 03:39 PM)

QUOTE (Aaron Cox @ Dec 27 2004, 03:22 PM)
coils should have a 3ohm impedence correct?

each manufacture is different...my Accel coil is 1.5ohms, not too sure what the Bosch coils spec out at???

apparently there are 6 types of blue coils IPB Image and to run a unilite you need a 1.5 ohm or better

Posted by: MarkG Dec 27 2004, 06:26 PM

Got the Pertronix today, but don't want to burn it up. Think I will just get a Blue coil to play it safe......

Posted by: DJsRepS Dec 28 2004, 07:14 AM

I put an MSD coil on my point system. The enclosed directions said the coil was for the eletronic mod pkg but may be used on points with an .8 ohm resistor and gave me an MSD part #. Went to the performance shop I bought it from who said he would have to order that. I tried it without the resistor and did not make it to the end of my street. Had to put ole blue back in then file and reset the points Dwell Timing. I tried an 1.5 ohm dodge resistor later with the MSD ran like crap. I will eleminate the points soon as my mark jumps around while timing it. I cant feel any play in the dist shaft but it must be there?... Any way call the coil mfg for the proper ohm size as they are all different. Put the trusty blue back for now..... This resistor thing sounds bassakwards anyway, you buy an really hot coil then cut back the imput voltage that cuts the output?? Whats up with that anyway.....Also our 914s have 3 OEM resistors in the ign system. No external input voltage resistor (an input resistor is built in coil thats #1.) then under the cap in the rotor #2, then in the plug insulators each have one #3. And if the plugs #4 or wires #5 had a resistor it would run like crap. My local flaps (discount auto parts kept crossing my plugs into a resistor plug) OEM calls for non resistor plugs and solid core ign wires.