123ignition distributor pointers

[Forssling]

Hi All!
I was fortunate to get hold of a very little used "123-Porsche-911-SMALL-6-R-V" distributor. I have heard nothing but good things about these units.

I am restoring a -71T and are soon going to get into the engine. That being said I have never run this engine and when I got it the Magneti Marelli distributor was in the boxes of parts.

What I'm trying to find out is if I need to use my CDI unit in my setup. The information I got so far is that it is possible to run the 123 distributor without it but the tach gets its info from the CDI so I have to solve that.

Anyone here running the 123 distributor? How is it setup? With or without CDI? If without, how did you go about getting the tach to work?

Any input much appreciated!
Jörgen Forssling
Gothenburg
SWEDEN

[Jonny H]

With CDI. Connect the red 123 wire to a 12V ignition feed. DO NOT CONNECT it to coil A (+).

Without CDI. Connect as per 123 instructions but you will need to get an inductive coil. The CDI coil is not right for this setup.

Your engine will be down on power if you go with the second option.

[ChrisHoover]

My 123 came in the mail yeterday. I spent last evening reading posts about advance curves. There is a great deal of good info on this site. Beware though LorenB shows up often!! Now I am trying to figure out the vacuum settings. My car is a hachet job by the prevoius owner. It has an MSD so I am keeping it. I am also using Bob Ashlocks Tach Adapt for the tach

[Forssling]

Originally Posted by Jonny H

With CDI. Connect the red 123 wire to a 12V ignition feed. DO NOT CONNECT it to coil A (+).

Without CDI. Connect as per 123 instructions but you will need to get an inductive coil. The CDI coil is not right for this setup.

Your engine will be down on power if you go with the second option.

Thanks! With the second option, will I still get my original tach working? And I try to understand the setup, could you explain why the second setup gives less power. No misbelief, I just want to learn.

//Jörgen

[ChrisHoover]

Here is my wiring diagram

[Forssling]

Hi Chris, sorry to say I don't get that diagram at all. To start with my 123 distributor only has 2 wires, black and red. I will run an original setup except for the distributor so I would need a diagram based on the original wiring.

//Jörgen

[Jonny H]

Originally Posted by Forssling

Thanks! With the second option, will I still get my original tach working? And I try to understand the setup, could you explain why the second setup gives less power. No misbelief, I just want to learn.

//Jörgen

Your tach will still work from the distributor black/purple wire

CDI makes more power on these engines as it delivers a more powerful spark. It’s due to the size and shape of the combustion chamber. No doubt there will be folks along soon to debate that. Put it this way - almost every early 911 race car runs CDI.

[ChrisHoover]

Here is the diagram 123 sent me

[ChrisHoover]

The distributor has a battery +12V, a 0V return also known as earth or ground and a trigger. Some models may not have a 0V wire. Instead its return path is through the chassis. I read in the documentation there is a threaded hole to screw in a 0V wire.

[Forssling]

Thanks Chris, that's exactly what I need! That also explains why I only have black and red wire, It's not the "tune" model. Mine I can choose from 13 preset curves by turning a microswitch.

Thanks!!
//Jörgen

[Forssling]

Originally Posted by Jonny H

Your tach will still work from the distributor black/purple wire

CDI makes more power on these engines as it delivers a more powerful spark. It’s due to the size and shape of the combustion chamber. No doubt there will be folks along soon to debate that. Put it this way - almost every early 911 race car runs CDI.

Thanks Johnny! Isn't it the coil creating the spark? And just the CDI (in the original setup) that triggers the coil? Couldn't I get the more powerful spark with a modern, good quality coil?

//Jörgen

[WMontald]

Did anyone tried the following?

Using 123Ignition Porsche-911-SMALL-6-R-V

Connect Black wire directly to the Coil (Red COIL)
Connect Red wire at 12V
Connect RPM Gauge Wire to Black wire of 123Ignition (so at the coil)

Technically I believe this works.....

Some say you get power loss as CDI delivers faster spark.
123Ignition claims that Spark is more powerfull.

What is correct?

[Hx911]

Originally Posted by Forssling

Thanks Johnny! Isn't it the coil creating the spark? And just the CDI (in the original setup) that triggers the coil? Couldn't I get the more powerful spark with a modern, good quality coil?

//Jörgen

Yes and no. In the CDI version the pints trigger the CDI, which discharges the Condensor through the coil primary, creating the spark voltage/current in the secondary winding.
CDI feed higher voltages into the coil than the 12v battery voltage that normalpoints without CDI ignitions feed

[47silver]

Use a cdi, cdi+ or msd with the 123 as i could not find data that said it sends a high volt signal to the coil. Cdi etc send >350 volts which then increases the output voltage of the coil. Using the 12v output directly to fire a coil from the 123 will result in performance issues.

[Forssling]

I have come a long way since I first asked this question. I will run original CDI and 123-ignition distributor. Soon the engine will go in my car and I guess the engine will be started for the first time early in the new year.

Wish me luck.

//Jörgen

[WMontald]

Originally Posted by Forssling

I have come a long way since I first asked this question. I will run original CDI and 123-ignition distributor. Soon the engine will go in my car and I guess the engine will be started for the first time early in the new year.

Wish me luck.

//Jörgen

I recently installed 123Ignition on my 911 see
post on installation
123Ignition distributor
and post on connection and performances so far
123Ignition distributor

But was wondering if this all could work without CDI?
And do you get same performances?

As understood CDI is only used to get sparks on High Rev engines...

[47silver]

A points and coil only ignition sends 20000 volts to spark plugs. Capacitor discharge send 35000 plus to the spark plug. This voltage is available at startup and to most engine redlines