is this to be believed ?

[zray]

".........Also, it is worth noting that some of the newer Holley carbs come with a "Power Valve Protector", [pic] or check ball in the base plate to prevent backfires from rupturing the power valve's diaphragm. This must be removed if the power valve is to function correctly under boost. ........."

from this website:

http://www.hangar18fabrication.com/blowthru.html


Z. Ray

[speedytang]

I have always purchased a modified base plate when using a Holley with a supercharger. I could see the a check ball being a problem.

P.S.
Did you ever figure anything out about the PSI drop.

[zray]

what were the mods done to the base plate ?

the psi drop was just a bad gauge, all's well.


Z. Ray

[speedytang]

Not sure what the differences are to be honest. I have been doing fuel injection for 20 years and when I built a dual VR4 for a boat I used carbs and ordered the base plates from Demon for supercharging.