Originally posted by UnderPSI
The secondaries will stay open by default unless vacuum is suplied to the diaphram. If you remove the vacuume line from the diphram, just plug it up so you don't have a vacuum leak. When the rpm's reach 5750, the ecm turns off the iab solenoid and no longer supplies vacuum to the diaphram causing it to open. When the secondaries are closed, (vacuum suplied to diaphram), the intake path is longer and more narrow and aids in the production of more torque at lower rpms (below 5750). If you leave them open all the time, you may feel a slight decrease in power at lower rpms or a bog after vtec cross over. If I leave mine open all the time it bogs around 5000 to 5500 and as soon as it hits 6000 it takes off again. Although mine is a b16 block, the b18 may react different.
problem solved with an AM intake manny !