It might have been cheaper and simpler to buy one of Jonny's CDI boxes and freeze the advance on your original distributor. His CDI has the capability to give you any advance curve you want. It'll run your tach too.

Very interesting post

On my 2,2 E, There is an intermediate ballast unit between the Tach and the coil
See picture

I plan to install a shiny new 123ignition programmable distributor

So I would be happy to know if I need to plan a specific/different 123 ignition wiring , considering the presence of this intermediate unit in place beteween the Tach and the coil .



http://forums.pelicanparts.com/uploa...1556362688.jpg

The problem with the tachs that use the intermediate unit is they need the intermediate unit to operate. Your tack is hooked up to the coil. It will continue to operate from the coil using the intermediate unit regardless of the distributor's trigger.

I changed to a 3.0L SC motor in my '71. The original tach works fine connected to the coil as it was originally, even though I have the electrically triggered distributor from an SC and a 6 pin CDI.

If you aren't planning on using the CDI, you may have problems with the older tach.

Sorry to bump this but curious how this worked out. I have a 2.4 with S pistons and solex cams and putting this setup in my car this week.. Thanks for any feedback

I'm about to start mine for the first time tomorrow. 123 distributor with no cdi and a 73S tach. It may need an MSD but will try without it first. I set advance to the 2.2S version. With your Solex cams, Solex selection might be best. My coil is the epoxy one that 123 recommended.

Where do I find that curve?

My 123 is the cheaper manual version with different manual switch settings for different curves. There's a cover on the side that pulls out.

How did all of this work out? I'm installing a 123 tune+ on my 2.7L and thought I might use your curve and wiring (I have streetfire ignition and tach adapter already as well as pertronix in the old dizzy).

Any update or different advice 3 years later?

TIA

John

From what I can gather from this post...
https://123ignitionusa.com/curve-tutorial/

Your MAP curve should look like this

No - kPa - Degrees crankshaft
1. - 0 - 0
2. - 84 - 0
3. - 87 - 10
4. - 99 - 10
6. - 100 - 0
5. - 200 - 0

Which make sense in my case because I've been struggling with my rotor not pointing to the plug at TDC, its always been about 10 degrees off. I haven't tested this yet but I'm hopeful that I'm getting close to figure this 123 out.

Good Day to you Gentlemen
I was referred to this thread by a good friend and engine builder who is a member of this forum. His forum ID is ICarp. He has generously offered to help any that would like or appreciate his assistance on installation issues with the 123ignition, to contact him. He has also been gracious enough to reach out to a number of my customers with installation issues. So while enjoying a 100% success rate and serving as a technical liaison for 123ignitionusa, he is dedicated to the sport and has a main interest in the Porsche 911. Ian is part of the team to make the sport more enjoyable. The simplicity of the 123ignition can be a welcome accessory to the success of your project. We are here to help and sort through the installation with you.
You are welcome to PM me directly and I will put him in touch with you. Just leave me a phone number.