An Official 123 Ignition Distributor Curve Thread, figured this would be helpful Options

[iankarr]

Hi Guys,

With more and more of us switching to the 123 Ignition distributor and all the questions coming up about how to set the curves on the bluetooth model, I figured I'd start a thread where we can all share tips and screen grabs of what works for our cars. I'll go first.

Jake_Raby taught me a simple method for getting the app and the dizzy in sync.
– First, follow the directions for installation (using the green light), which will get you to a point where the car runs.
– Set a curve point for 8 degrees @ 1K RPM, a point for 27 degrees @ 3000 rpm and a point for 27 degrees at 5K. Load that curve into the 123 distributor.
– Hook up a timing light, cap off the vac advance and rev the engine to 3K RPM. I like to aim at the notch on the flywheel. Rotate the 123 until you’re showing 27 degrees BTDC @3K and then lock the unit down.

The app and dizzy are now synched and you’ve approximated a simple stock curve. Now the fun begins. Drive around and see if there are any flat spots in acceleration. Make note of the rpm’s where the power seems to dip. Add points there to fine tune the advance. You’ll probably need a little more advance a little earlier. You may also need to tweak your idle advance a bit until it runs smoothly. Of course the condition of your engine, altitude and a bunch of other factors come into play. I live at 6,000 feet and here's what my freshly built 2056 with 9590 cam in my bumblebee is happy with: (Note that I've zeroed the MAP curve. I haven't been able to see a difference using it, but am still experimenting. If someone can offer suggestions for that, please do!)






I have a new unit for my ravenna car and will make a full video on that when I install it this winter. Will post a link in this thread when ready.

[mkinne]

There seem to be a few 123 curve threads around, but I had previously bookmarked this one, so I hope this is a good place to ask...

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Picked up a 123 distributor (TUNE+ 4-R-V-POR-IE) in the recent group-buy, installed it last week, and have been getting out for a few test drives.
Overall initial impression is very positive and the changes are instantly noticeable, including smoother idle and much cleaner takeoff from stop.

I do have one issue haven't been able to make progress on, though.

Under modest-hard acceleration or steady load (uphill), I hear some pinking/pinging that I have never noticed before (windows are usually down). This is mostly in the 3~4k rpm range, but I might also hear it a little into lower rpms if lugging or higher rpms if I keep my foot in it longer. I have tried several different curve settings from extra mild (20* max advance) to fairly aggressive (30* max advance), and the pinging is always there (maybe just a little more with aggressive settings). I also don't notice a difference with or without the MAP curve enabled (as many others have mentioned).

I started out with a fairly full centrifugal curve (too many points, trying to be too clever)...
... but quickly moved back to a simple curve (like the one below, thanks @mgphoto ) that is much easier to make changes on the fly.
(IMG:http://www.914world.com/bbs2/uploads_offsite/photos.smugmug.com-1406-1700611070.1.jpg)

MAP curve is the one that was in the 123 as received and has been disabled most of the time.

I've tried moving the 500/1500 points as low as 0/2 and as high as 10/10, which seems to effect idle and startability (higher values = higher idle and harder to crank).
I've tried moving the 3500/8000 points as low 20/20 and as high as 32/32, which honestly doesn't feel much different (higher values = slightly stronger off the line and pulls a little harder).

I also tried playing with the "Tune" function on the App dashboard (very cool!), but that is almost impossible to do without a copilot and I didn't know what I was doing anyhow.
I noticed it did generate some info, but I haven't found an explanation for what it means.
(IMG:http://www.914world.com/bbs2/uploads_offsite/photos.smugmug.com-1406-1700611070.2.jpg)

So far, the pinging is still there in all cases and the usual rpm range.

Feels like I could be missing something obvious, but don't want to continue experimenting at risk of causing damage.

Any suggestions appreciated.

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A little background for context...

Car is a '73 2.0L with stock D-jet except for FJ67 injectors.
Engine is an older 2056cc build with lower compression 'dished' pistons.

Prior to installing the 123, the original distributor (231 174 009) was still in place, including a Compu-Fire ignition module that has been in there probably since the late 80's.
Bosch blue coil has been in use a few years (Ed said it should be OK).

Fuel in the tank might be 87~89 octane and might be a couple months old. I never really felt a difference between cheap 87 or expensive 91 and car seemed to run the same on any, so I was never picky.

-M