Hi all, I bit the bullet and installed a 123-TUNE programmable electronic ignition on my 1969 E-type 2+2 with triple SU’s and BW8.
I did this because I felt that the car lacked power - the ignition was not advanced enough. When I advanced the distributor to a level that the car felt ‘crisp’, the starter would not turn the engine over anymore - too much advance!
So I got myself the 123-TUNE, with which I can program the distributor with my smartphone
I programmed a curve from the factory specs of the 41060A, but a bit more advance at higher RPM and 0 (static) advance at 0 RPM. Vacuum advance remains factory spec.
The result is an engine that starts easily, pulls well and achieves better fuel economy. I still have to visit a rolling road, but for now I am a happy man.
Could you share the curve settings? I recently swapped a rebuilt S1 4.2 into my Mk2 and the shop set up the 123TUNE. I’d love to see if I’m close to the factory setting. Thanks.
these are the fixed curves that came pre programmed in the first versions of the 123 distributors, I don’t think the trick mentioned by Andrys can be achieved with the older models as the curved are fixed.
I also have a 123 distributor (on a Lotus Elan), with 2 programmable curves (via an USB cable), and I’ve implemented an other similar trick to stabilize idle around my preferred idle level.
Without wishing to detract from the 123-tune, it seems to me that if you were having to advance your old distributor to the point where it wouldn’t start, then there must have been a fault with the centrifugal advance weights. I had a similar problem with my Austin Cooper and it turned out the weights were simply seized in place with years of old oil and dirt and a simple clean-up had it running again as good as new.
Having said that, there’s no denying that the mechanical advance system is pretty crude, and the 123-Tune has to be an improvement.
I should have posted my curve in the first place, apologies for that. Here it is:
You see, I did not deviate a lot from the standard curve, but put static timing on 0 and went “maximum-standard” from 1050 rpm onward. Vacuum advance is standard.
What one should bear in mind is that I drive a slush box. It spends a lot of time sub-2000 rpm, because of the low stall speed (1700 rpm) of the BW8 torque converter. Below 2000 rpm and too little advance, the engine struggles. The BW12 torque converter stalls at 2300 rpm, which would give a livelier engine, but with more loss and worse fuel consumption.
Hi Andy, I appreciate that I was not the one asked, but in my experience fitting a 123 to an S2, the tach was not effected. I made use of the existing wiring and connected it in with as little changed as possible. The logical wiring was unchanged. I did/do have a very occasional loss of tachometer, but I think that may be a connection issue with otherwise-original wiring and it hasn’t happened for a while.
btw, I went with setting “D” for the advance curve and no apparent issues with that.
That’s right - 16 fixed curves for my 123. Ideally need to find the one that best matches the upper and lower tolerances for the application (3.8 or 4.2). The red and blue loci are just graphs of the table in the factory manual. Paul
Hi Andy, in my case (1969 S2) the tach was not affected, like Liam said.
What will be clear now, there are two types of 123 being discussed in this thread. One has the 16 preset curves and has been on the market for quite some years now. Mine and Nic’s is the programmable version in which you have to enter your own curve. You must know what you’re doing, since wrong ignition timing can be bad for the engine (detonation).
