Petronics Coil Questions

[kissmyaxle]

I have tried to research this and cant find exactly what I am looking for. Need advice on the proper coil for a petronics ignition. I am switching to this and have read various Ohms are needed in multiple situations (determined by the year & ballast, etc.) so as not to blow your coil. Mine has a ballast but not sure if mine came with one factory or not. Was running it without one when I bought it and then the coil exploded....yep...in my face... Pulled one off of a 73 with the ballast and hooked it up and it ran great until yesterday....tinkered too much under the hood and now I am dead in the water....which got me to thinking of doing this little conversion. I have a 65 fst straight f. Anybody have any experience they can offer on this? Brand, ohms,...color? jk. All help is appreciated.

Ben

 

[Downey]

My understanding is that the stock Toyota coil puts out 18,000 volts, and the Pertronix coil puts out 40,000 volts (which is needed to keep up with the Pertronix). Frankly though, I don't know which Landcruisers came with a ballast resistors, and evidently Pertronix does not know either. Evidently some ballast resistors were visual and some were hidden in the wiring harness. What I do know is that the Pertronix DOES REQUIRE a ballast resistor, and you will burn up the Pertronix without one. So the big dilemma is "what Landcruisers came with a ballast resister, and where is it"---school me.

 

[Pighead]

What I do know is that the Pertronix DOES REQUIRE a ballast resistor, and you will burn up the Pertronix without one.

Well, that is just the opposite of what I heard...
My '74 (late F) did come with the ballast resistor, it was bolted to the old coil clamp IIRC, but I was told to bypass the ballast resistor when I installed the Pertronix. So I did. I do use the Pertronix coil though.
That was about 15 years ago, still running..

 

[kissmyaxle]

Pighead what type of pertronix coil do you have? how many ohms?

 

[Magnum44]

I may be wrong but I thought all DC coils had to have resistors so they won't burn up.

 

[Pighead]

Pighead what type of pertronix coil do you have? how many ohms?

I dunno, it's black and says "Pertronix" on it...I just called them and asked for the coil that goes with the ignitor.

 

[laguna80]

I got the pertronix system. I have the flamethrower II coil, the instructions said not to use a ballast resistor. I got mine from this site: PERTRONIX 45011 Flame Thrower II Coil Black $31.95 BUY ONLINE The coil did not fit the stock bracket despite what the website says. It was too thin.

 

[Nomis]

I got the pertronix system. I have the flamethrower II coil, the instructions said not to use a ballast resistor. I got mine from this site: PERTRONIX 45011 Flame Thrower II Coil Black $31.95 BUY ONLINE The coil did not fit the stock bracket despite what the website says. It was too thin.

X2 - running this coil with the Pertronix IgnitorII on a early vac. advance dizzy - no ballast resistor.

 

[Pin_Head]

A rule of thumb for 12V coils:
If the primary resistance is 1.5 - 2 ohms, you need a 2 ohm ballast resistor.
If the primary resistance is 3-4 ohms, no ballast is needed.

All coils are capable of putting out a higher voltage than is necessary or desirable. If the voltage is too high, it will lead to corona discharge, insulation breakdown and ultimately failure and unreliability. There is no up side to having a voltage higher than needed to make a spark with the normal spark plug gap and under all operating conditions. Stick with the stock coil. It is all you will ever need and it will last longer than you will.

The only reason for ballast resistors is to allow the system to bypass it during starting when the battery voltage is low to improve cold starts.

 

[kissmyaxle]

Thanks for the help fellas. Thats what I needed to know.

 

[kissmyaxle]

The only reason for ballast resistors is to allow the system to bypass it during starting when the battery voltage is low to improve cold starts.[/QUOTE]

Pinhead how does this config work? I have been reading on the search for the hookup you mentioned above, but bunko on the info. I have my hot wire connected to the BR on the pos. side/ the neg side has a wire running to the pos side coil/ neg on coil running to the dist. Question is how does this bypass during cold starts if it has only one wire running to the coil via the BR? Does another wire need to bypass the BR?

 

[Pin_Head]

Some years have an additional wire from the starter solenoid that also connects to the coil +. This wire is only hot during engine cranking when the battery voltage drops.

 

[shelfboy1]

i used the other brand it did not require a new coil and was simple to install nad has been working for 10 years now .and yes jim ballast resistors are mounted to the stock toyota coil ,have many of them laying around here good luck

 

[tlc_4play]

A rule of thumb for 12V coils:
If the primary resistance is 1.5 - 2 ohms, you need a 2 ohm ballast resistor.
If the primary resistance is 3-4 ohms, no ballast is needed.

I have the Pertronix with a 1.5 Ohm coil and the installation instructions supplied by Pertronix recommended a 2 Ohm ballast resistor - which I got from Toyota

It runs perfectly

 

[kissmyaxle]

Thanks fellas. Think that pretty much covers my question.

 

[FJ40Jim]

and yes jim ballast resistors are mounted to the stock toyota coil ,have many of them laying around here

Only on 72-77.
78-80 BR is a resistor wire in the harness.
81-later uses a variable dwell ignitor to do away w/ the need for a BR.