mk1-forum.net

Spider wrote:@ ianh1968 re: your 123.

I haven't seen a fully programmable 123 like it appears you have,
<SNIP>
An input for a Knock Sensor would also be handy, does it have user programmable inputs?

Most of the existing electronic distributors just emulate their old mechanical counterparts in that the
"curves" they have are basically two straight angled lines, followed by a flat one.... This would be
exactly how a setup with weights and two sets of springs would work.

Yes, my 123 IS programmable, and no, I do not get a commission from 123ignition...

Check out the 123ignition website, the one you are looking for is called a 123\tune
or a 123/tune, depending on who is doing the typing. For a pre A+, ie the original Lucas 25D/45D
replacement, you will need a "123/TUNE-4-R-V-G".

I have bought two of these from Roy at Southern Carbs in Crawley, West Sussex.
http://www.sciperformance.co.uk/page_1796358.html/

You can view/download the manual as a .pdf from here:
http://www.sciperformance.co.uk/sitefil ... ual_GB.pdf

The dyno I used is only about 3 miles from his shop, so it was very convenient when a
different spring was required that neither I nor the dyno op had in stock.

The 123/tune allows 10 "centrifugal" points to be specified and these can be pretty much at
any RPM as long as the lowest is at 500RPM. You can also set a rev-limiter. At the same time,
it also allows 10 vacuum points to be programmed, and you can specify at what RPM you want
the vacuum advance to become applicable.

All of the above settings are applicable to both of the 2 available setups. Setup 2 can be
triggered whilst the engine is either off or running by putting +12v on a yellow wire which
comes out of the unit.

Currently, it does not have any other inputs and I did query with them about the temperature
chip. As I said before, the temp chip does not allow an extra layer of mapping, at least it did
not when I asked.

As regards a "Knock Sensor" input, this could be achieved (sort of) by setting up a softer
curve like I did and getting the sensor to trigger curve 2.

Another good use for the curve 2 facility is for people who have nitro-kits which require
different timing for use either with or without the nitrous.

Anyone who is complete electronics/computer nerd may be able to create something
which would adjust the timing "on-the-fly" via the USB port. When a laptop is connected,
it is possible to advance/retard the timing whilst the engine is running by starting
"Tune Mode" and pressing 'A' or 'R' on the keyboard. The only problem with this idea is that
the USB socket is not even slightly water-resistant. It is accessible behind a screw out bung
which is quite discrete when fitted. The general idea is that you adjust the settings, then
remove the cable and put the bung back in. Apparently the thread is "PG9" and I did get
some cable glands to fit from Radio Spares (RSOnline), but there is still the bulk of the
standard (small/camera) USB plug to contend with...

ianh1968 thanks heaps.

I have done my own home grown mappable ignition and wasn't easy, in fact, I've only done one and any time since, just bought a CSI. But none the less, I did incorporate the facility to be able to have 2 curves and then select between them. It has 11 programable points and like yours a rev limited. It also has MAP Inputs and a Knock Sensor Input (which retards timing by 6 degrees on the detection of knock for around 1 second). I wouldn't do another though, I tend to use this one to sort out what is needed on an engine and then either program a CSI as close as is possible or have Scortcher Ignition build be a dissy emulating that curve.

However, I'll have a bo-peep at 123 again as this does sound the pretty damn good.

Thanks again