I found that the lower I set it, the better I could
idle. So I loosened up the screw all the way. that gave me about 40
psi with the engine off and 32 psi at idle (manifold referenced). I can
idle as low as 800-900 but it is not smooth. It really will not run
smoothly until up around 1200-1400 rpm.
David Leonard
I also use 40 psi, engine off; drop to
about 32 at idle. My experience is very the same; and that is running
with the staging reversed; i.e., it uses the secondary only (slightly lower
flow, MSD injectors out in the TB) at idle. Using the 560 CC primary only
the idle is terrible, and doesn’t smooth out until above 2000. The mixture
is too rich, and as it is reduced; before it smoothes out - the engine
dies. I think this is very indicative of the pulse clamping issue.
I haven’t tried lower FP.
That should help, but may have other disadvantages in injector spray pattern,
etc.
Al