123 Ignition Vacuum Adv, Learn me on some vacuum Options

[nditiz1]

Ok so I'm currently running the 123ignition dist on my 2056 with dual webers. I read the instructions and don't understand the mapping. I also don't know how it all works together. Can someone educate me on the vacuum adv and what curve would be best? As the rpm's increase it creates more vacuum thus creating more adv, but if I already have a curve setup to go from 12 degrees at idle to 28 degrees at 3000+ will the vacuum adv move the timing even higher once it is hooked up and mapped?

[BeatNavy]

Yes, IIRC the difference between curve 2 and curve B is the former has a vacuum advance, while the latter only uses retard.

[DRPHIL914]

Yes, IIRC the difference between curve 2 and curve B is the former has a vacuum advance, while the latter only uses retard.

ok, I found the chart on line after a bit of digging and it shows the 1-8 vac advance setting as starting at 100mmhg and ending at 300mmhg(hitting max advance), where as on the chart under those headings for the A,B,C,D,E etc it just had a dash in both columns, so I thing you recall correctly.

that would lead me to believe that the advance in that case it preset, and that we could experiment with this a bit, but first thing I will do is to try the current setting of B, which is 2200rpm/22 degrees adv and then compare it to C, where the advance curve is programed for max at 3400/23, which I believe is closer to stock. I think I remember that Mike had said this helped his idle, mine is really low on the B so it might help to go to the C , but either way this seems to be so much smoother. I can tell you from the readings of the AF meter I am now not running so rich. I will be watching to see ho the oil and head temps are doing. I know being too advanced at high rpm is bad for the motor over the long term.