123Tune programmable distributor

[tjb0274]

Thought I'd post a quick review of these beasties after installing one in my Ricciardi recently. It's basically a completely programmable version of the 123Ignition distributors that I think a few members have already. The idea is to have a computer controlled breakerless ignition inside a standard distributor body, so no ugly modern box in your classic car, and no modification required to fit it.

I got mine from Leen APK in the Netherlands, and they were very good about working with me to determine which model would fit the twin cam. For the record, it's the 'D' model.

Putting the distributor in is straight forward. You just need to have a crimp kit on hand since the wires come un-terminated and need to be cut to the correct length. Since the advance is set via computer after installation, I set the static advance to the TDC mark. The distributor has a built-in LED to indicate when the rotor is lined up with a spark plug, which makes setting it up pretty simple.

Once it's in, you install the software (downloaded from the 123ignition website) on a laptop, and then connect the laptop to the distributor via a USB cable.

The software runs in two modes. When the ignition is off, it will show the current advance curve, and allow curves to be loaded or saved. Curves are created or edited by specifying revolutions and advance for up to ten points along the curve. You can drag the points around using the mouse, but I found it easier to type the numbers in. I found a spreadsheet on alfabb.com with all the curves for the various distributors used on the different twin cam models, and started by entering a couple of those manually. The distributor body also has a vacuum sensor, and if connected a separate advance/retard curve can be set based on the input from that - not needed for my 1750, but handy for anyone with a vacuum advance (or possibly a turbo).

When the ignition is on, you can't edit the advance curve, but can instead see a display showing current revs, advance, distributor temperature, and coil current. You can also advance or retard the ignition by any amount - this results in a temporary change to allow for experimentation while the car is on a dyno, or during a road test (obviously a passenger should be operating the laptop in this case!). The software has a stopwatch function that can automatically measure time taken between any two chosen rev points to assist with road testing.

The system seems to work really well. With the old Bosch mechanical distributor I had a choice between top end performance, in which case it tended to idle poorly, foul the plugs and spit back a lot around town; or driveability in traffic, in which case I lost a bit of performance at high revs. My engine is now running far better than it was previously, and I've been able to customise the advance curve to be more conservative at lower revs for better throttle response and idling in traffic, while preserving the advance at higher revs. The difference is really noticeable from behind the wheel, and plug cuts confirm that the engine is running much more cleanly across the rev range.

You can also pre-set two different curves, and wire a switch to one of the distributor terminals to change between them while driving.

Where I think the 123Tune would really come into its own is when tuning a modified engine. Instead of relying on a pre-set curve in one of the aftermarket mechanical distributors, or fiddling about with springs and weights, you can completely tune the advance curve for the needs of the specific engine.

Haven't really hit any negatives so far - the distributor body seems very well made, and it takes standard caps and rotors, so replacing those parts shouldn't be an issue. No points or condenser to wear out. There is a bit more slack in the drive engagement than I expected, but once the engine is spinning I don't think it makes a difference - just something to watch out for when setting the static timing.

Other than that, my only wish would be for an externally mounted USB socket - the socket is inside the distributor, and is reached by pushing the cable through an access hatch. It's a bit of a fiddle (best to have the laptop connected first, so you can hear the chime when you get it right), and it means that while the cable is connected there's an opening for dirt and grease to get in (there's a plug to put in the hole when not connected).

[alfagtv58]

Not sure if you know, but it seems that the max rpm for these is 7000rpm.....not enough for my race motor?  Do you have a link to the specific one you used?  Did you buy it from Nl or the aust agent? 
I found this one, is it the right one? http://www.123ignition.nl/id/40.html

I'm starting to look into this as rumour has it Group S will soon allow electronic ignition....no more points, yay!

[tjb0274]

Not sure if you know, but it seems that the max rpm for these is 7000rpm.....not enough for my race motor?  Do you have a link to the specific one you used?  Did you buy it from Nl or the aust agent? 
I found this one, is it the right one? http://www.123ignition.nl/id/40.html

I'm starting to look into this as rumour has it Group S will soon allow electronic ignition....no more points, yay!

Hi Phil - no, that's the one with fixed curves. This is the one I have: http://www.123ignition.nl/id/50.html. The 'D' model is the correct one to fit the Alfa twin cam. Reading the text on that page it looks like it can cope with up to 8000rpm - I presume that wouldn't be enough. I don't know what the limiting factor is - whether it's in the hardware (e.g. timer resolution or similar) or just an arbitrary software constraint.

I think there was a thread on alfabb.com about the capacity for higher revs - I'll see if I can find it and post a link.