I have read a bunch of threads on vent tube extensions. As far as I can tell they are talking about adding tubing to the carb vent tubes and having the end of the tubes facing the air coming into the carb hat. What does this really do? Are they over pressurizing the air in the float bowls? It seems to me that the goal should be to make sure the pressure inside is the same as inside the carb hat. If air moving over the ends of the vent tubes reduces pressure that could be a problem. Has anyone tried these? Any thoughts or better description of what they are doing.
This has always struck me as a bandaid for a carb that won't flow enough fuel on boost. Getting the emulsions/air bleeds right, and boosters that flow enough it shouldn't need it. I think it helps non-annular homebuilt carbs get the needed flow out of the regular boosters by upping the pressure in the bowl. That's my .02 I'm sure there are others with different experiences.
Seemed kinda weird to me. But those guys over at turbomustangs do some strange stuff with carbs. Do not see the folks at the major carb shops talking about this.
