Proform 850 dialing it in closer

Quote from Mark
2 configured like the old style cast Holley blocks always works. I use 3, but opt for smaller holes .-020-.021 range. Of course I also use different boosters...
post 15 Emulsion Tuning

Quote from Tuner.

In my experience data logging WOT AFR an irregular saw-tooth A/F trace occurs when the e-bleeds get over .028". In the AFR logs that were in the Innovate forum (do you recall?) the BG carbs with .031" well bleeds [aka e-holes] produced an erratic AFR data trace that looks like a saw-tooth. Changing the MAB from .036" to .028" helped, but changing the well bleeds to .028 flattens the AFR trace such that it looks like a lot of smoothing is applied, which was not the case, the carbs just delivered the fuel more consistently. The A/F in some logs (from carbs with oversize bleeds) exhibited not only saw-tooth but also the tendency to switch between two AFRs for a second or more, as if the jet size were changed with the flip of a switch, sometimes on a gear shift and sometimes in a single gear, rich-lean-rich, 12/1 – 14/1 – 12/1, all at WOT with the RPM rising and without moving the throttle. One I distinctly recall in the Innovate forum was a Pontiac with a 4 speed but others did it too. Changing the bleeds to the old-school Holley configuration eliminates that erratic behavior.


Hmmm Saw tooth, good description and mine look a lot like that one.
Spikes lean on gear change.........
ok off to find data.