Originally Posted by DrCharles
I agree, I'm posting on RFS too. But it's hard to argue with the Innovate results scope That engine has a 9" idle vacuum.
And that was my biggest problem that started all this - idles fine, runs pig-rich at cruise. I went all the way down to a .041 TSR and it helped a lot, but also created a super-lean flat spot...

If I tried their approach, I would want a bit more idle fuel (doubt my combo would even run when off the mains with a .020 IFR!)

So rather than return to what I know didn't work (as-delivered), I'm thinking of something like this (along the unconventional lines of the article):

Original Current Proposed
IFR .033 .031 .029 - this is probably where I should have STARTED leaning, .031 helped but wasn't near enough
IAB .070 .082 .063
TSR .081 .041 .074 - even with .041 it's not right, so go back to a normal size
MAB .030 .082 .085 - want to delay the mains
MJ 79/88 75/86 75/86
PV 5.5" 9.5" 9.5" - cruise vac 15"
PVCR .059, will change last, probably .070 or so with the smaller PMJ

This old thread: https://board.moparts.org/ubbthread...48706/holley-rich-at-light-throttle.html
points out that it'll never be right when cruising on the t-slots, because the idle vacuum is less than the cruise vacuum... but I think I can get closer than it is.

What is most important to me is to drive at 60 mph without being overrich, also 25-30 mph - because that's where the car spends most of its time on the 8 mile drive to town, then cruising on the street.
Rough idle is a given with a 272 @.050 cam, and I can live with a little flat spot at small throttle settings.



An .085 MAB a will not delay the mains. Don’t forget that the MAB feeds the emulsion stack too. So if you have an assload of emulsion (you don’t need it) the MAB has to be big enough to feed the emulsion bleeds and correct booster timing.

I’ll go read the link because I’m interested but that big MAB they used got the mains going earlier unless they have something else funky.

Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston