Programmable MSD 6AL-2 questions

[SSLance]

Originally Posted by 68Cuda

now, if that does not confuse you, the graph adds retard, not advance. So, not only is the pressure graph kind of backwards to conventional thought, so is the advance.

Originally Posted by 68Cuda

So, if I want 15 degrees advance at 20" of vacuum, I set 15 degrees more initial than previous, set my retard to 0 for anything up to 5psi, then slowly ramp in 15 degrees of retard all in by 14.5 PSI. This would give you a linear 15 degrees of "advance" from 0 to 20". What is the best curve - I don't know. I think the stock distributers can give you somewhere around 20 degrees at 20". I would start with, maybe 14, see how it likes it, progressively try more. This will cause you to have a higher advance while at idle, but that is OK, it will idle a little smoother, take less throttle screw and be less likely to diesel when you shut it off.

I don't think I want any more advance at idle...do I? The throttle blades are completely closed and it's idling at 14.7:1 AFR at 850 RPM. Any advance at idle I add just increases the idle RPM and vacuum. I guess I could start fiddling with the idle air screws to dial them down, but am I just chasing my tail here? Heck I was trying to get the initial down to 6* to try to slow the idle down a bit more.

It's good like it is. It drives great, no issues anywhere. Maybe just a bit of a stumble when lugging it with the primary side about half open, but giving it just a bit more gas clears that right up.

I guess maybe that means it wants a bit more advance say at 1000-1500 RPM with high vacuum...right? and as soon as that vacuum drops (throttle opens) take that advance away so it doesn't detonate.