Good advice, as it turns out ;) My Autometer dash vacuum gauge agrees well with two underhood-type large gauges.
During the 80 mile round trip to the car show, I had an opportunity to watch the gauges more carefully. I filled the fuel cell with alcohol-free pump premium.
Idles around 13.5-14 AFR. The lumpy idle from the long duration and overlap already smells bad enough, I don't want to richen it more if I don't have to...
Cruise 14.5 @ 15" Hg.
This PV starts to open around 7-7.5" (it's clearly stamped 8.5!)
Fully open at more like 6", where the AFR drops rapidly to 12.5 and stays there as I keep opening the throttle more to stay at 5-6". That does not last long even in 4th gear :)
I know it's not a true binary switch - it has to open far enough so that my relatively large .066 PVCRs are not restricted by the PV seat. Now I'm wondering what exactly the PV rating is measured at - where the valve starts to open? Or fully open? Either way the one I picked does not seem to be quite rich enough. Time to try the (alleged) 9.5" I guess!
