Pertronix guys , what coils

I went with Pertronix's advice and put in the FlameThrower IIs with my Ignitor IIs. Planning to play with plug gaps over the summer.

 

As above. Pertronix II and Flamethrower II as recommended by Petronix. Plug gap approx 1.1 to 1.3mm.

 

+1

... talked to Summit Racing and they did not recommend increasing plug gaps. They said they couldn't see any difference.

/Pero

 

The Bosch blue coil is not a very powerful coil and not really the best choice for a performance car. With an Ignitor I i would recommend to use either a Pertronix Flamethrower I coil, or a Bosch red coil with resistor.

 

Adrian,

There was an earlier thread suggesting that resistors aren't required when you switch to a Petronix from the point system. I'm running Bosch blue coils now (with the internal resistors), but I've got two sets of NOS Bosch red coils just sitting on the shelf, but no resistors in my collection.

Is it possible that the earlier thread was correct, i.e. that the resistors are only to protect the points, so no points, no resistor needed? I'd like to try the red coils, I don't want to cook my new Pertronix!

Thanks, Jeff

 

I thought it specifically stated in the instruction manual that coils with resistors (whether internal or external) were required?

In any case, I have been using Blue coils (the Brazillian made ones) with my Pertronix set-up and have been really pleased with how it runs.
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Jeff,

you can run Bosch red coils with any 1.2-1.8Ω resistor. Here is a 1.6Ω resistor on Amazon:
http://www.amazon.com/JEGS-Performance-Products-Ballast-Resistor/dp/B007VR760C/

Resistors are used to limit the maximum coil current which avoids/reduces overheating of the coil when the coil is fully charged.
Capacitors protect the points by reducing the arc when the points contacts open.

Pertronix Ignitor I setups do require a resistor on 4-6 cylinder setups (each coil runs 4 cyl in the 308 setup) if the coil resistance is lower than 3Ω, so you need to add a 1.6Ω resistor as above.

Best,
Adrian

 

Thanks Adrian. Now that makes good sense to me, and thanks for the link.

On wiring this up, does the following sound correct?:

I'd take the incoming wire from the ignition switch to one side of the resistor, then a short jumper from the resistor to the "switch" side of the coil, then the normal wire from the other terminal of the coil to the distributor.

As a side note, when I took out my Marelli coils/resistors and went to Pertronix and Bosch blue coils, the resistors were on the distributor side of the coil. That didn't seem to be right somehow, but that is the way it was on my car. Could have been a wiring mistake by a previous owner?

Best regards, Jeff

 

Peter,

I'm running the exact same setup as you, with good results. However, that has never stopped me from messing with success so I'm thinking about trying these Bosch red coils. What's that saying? "Fix it until it's broke".

The instructions that came with my MR-183 Pertronix didn't mention resistors at all, but maybe there's something in the small print I'm missing. And these instructions are pretty basic, and they probably presume that everything else in the ignition system will be as set up originally, so resistors if needed are already there. Also, Adrian's post sounds like good advice, so resistors it is.

Best regards, Jeff
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Yes, all good.

That is indeed a wiring mistake. The resistor is always in between the supply (battery +) and the coil so that it can be overridden by supplying +12V directly to the coil when starting the car. This type of setup gives a hotter spark while starting, it was deployed in the 308 GT4 but not in the 308 GTB/GTS as far as i know.

 

The PDFs you have attached look a bit outdated, have a look at page 2 figure 3 on this download:

http://www.pertronix.com/support/manuals/pdf/ignitor12vneg.pdf

 

Thanks Adrian. That is very helpful- you saved me cooking my Pertronix! Jeff