123 Ignition

[FresnoBob]

I've been playing with my new 123 ignition with Bluetooth trying to optimize starting and performance at various rpms.  I have the car timed to exactly 30º at 3,000 rpm for my 250 motor with a 051 distributor.  I have several questions that I haven't been able to answer through the various search channels. 

1) I find the car starts better with the timing set at 30º than 35º (at 3,000 rpm).  Does this make sense?  Will the car start better the closer the idle timing gets to TDC?

2) I find the car idles well and accelerates smoothly when I set the advance to 10º at 500 rpm and 13 at 1,000 rpm and then eventually increasing to 38º at 4,000 rpm.  Is this from TDC or the 8º at idle?  The A/F mixture is 11.7 at idle and then increases to 17-18 at higher rpms.  Is this reasonable? 

Thanks for your collective thoughts. 

[Nicolas Aristodemou]

Timing setting at 3000 rpm should have no effect at starting; timing at 500rpm would be more relevant.

The A/F ratio of 11.7 is very lean, maybe you will have difficulty in starting.

I am using the curves below on my 280SL, you will notice that I have built the vacuum advance into the “centrifugal” advance curve to avoid issues with my emissions control car. These settings are working very well for me.

Nicolas

[Pawel66]

One of my observations while setting the mixture is that when you get it really lean, you do get het start issues.

11.7 is far too low. 17 is far too high.

Again, my observation was: get it right mire or less for full load (normal driving), then do the idle. As I do not have equipment to measure the mixture while driving (measurement at stand still at high rpms is useless), I did the setting by the color of the spark plugs - to get them in light or medium tan.

123 settings I did as per the recommendations here: 8 BTDC at idle, 38 BTDC at 3000rpm, everything connected, measured with the strobo lamp.