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Flow would increase, but you're thinking about it wrong. The motor doesn't know it's boosted mechanically or not. Vacuum is often used incorrectly. The engine doesn't see vacuum, it sees reduced pressure. N/A the engine sees atmospheric pressure. If you add 1 bar under boost, that's a total of 2 atmospheres. So the flow bench would have to have the pressure drop increased. I've done it out of curiosity and a port that went turbulent at 28in did indeed flow more air at 35in. I don't know what the numbers are exactly, but more pressure will force more air through the same size hole UNTIL you've got the port saturated. Which is why I go for volume on engines I know are going to be boosted.


Im looking at different lobe profiles that have more lift at the same duration. My goal would be to increase flow at boost without sacrificing low end performance at vaccum or no boost.
Allan G.

1970 Challenger w/572 Hemi street car and my pride and joy. 1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno. 1976 Cee Bee Avenger Jet Boat - 460 Ford powered.