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Old 04-20-2013, 03:47 PM
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bentwings bentwings is offline
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Willys I think you mean vacuum under the carb.

As for can be assured your "pulse rate" will take a jump as boost goes over 5 psi. haha You may have a "heart attack" if it goes over 8psi and motor starts detonating.

Just plug a vac/boost gage in the manifold under the blower. I don't worry too much about carb vacuum as the PV is boost referenced anyway. You will always have vac under the carb. If you have the small air cleaners in the scoop like many of us use the boost may not be as high as it could be and the carb vac can go up due to the restriction. I keep mine really clean and very very lightly oiled so I don't see the problem just cruising.
If I was to race the car I would take them out.

I also take the vac advance out of the manifold. However be aware that excess boost can pop the vac adv diaghram. I've done it twice. It would be nice to have a 2 way check valve in this line but the only one I've run across is too big and ugly. I have one for the vac modulator on the trans but took it off as I found I didn't need it.
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