Yeah, I clicked on the link. That is the WRONG way to time power valve opening.
Holley KNOWS at his, they just don’t want to admit they’ve been doing it wrong for decades and are STILL telling people to do it wrong.
No wonder so many people want to junk their Holley carb. When the vast majority of tuners out there do something so wrong as setting PV timing off of half of idle vacuum it’s no wonder they hate them. It’s no wonder they get piss poor fuel mileage. It’s no wonder they need to run accelerator pump nozzles so big they move the fuel gauge every time you touch the throttle.
FABO’s 12many went out and tested between the wrong way to time PV opening verses the right way to do it, and posted his results here. It should be made a sticky.
No matter how many books are written, no matter how many dumbtube videos are produced, no matter how many times its repeated on forums, blogs, at dyno session, drag strips, bars, strip clubs, BBQ’s, Thanksgivings, Christmas, New Year’s Eve, bachelor parties or anywhere else two or more gearheads get together and the subject comes up it is still wrong to set PV timing from 1/2 of idle vacuum.
Doing it that was is 180 degrees wrong from the way the PV operates. The PV has zero to do with or effect on the idle circuit.
It’s that simple. That’s not how it works, that’s not what it’s for.
You set PV timing 2-3 numbers LOWER than CRUISE vacuum and then you need to go back and unscrew all the wrong tuning done by timing the PV the wrong way.
