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Joined: Jul 2003
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From: Miami, FL
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i have a mild streetport and i get like 14 to 15 @1100 rpm. sometimes after getting on it a couple times it drops down to like 10-11 @ 900 or 1000 RPM. i dont know why but i know it works good. 386RWHP @ 16.5 PSI
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Joined: Feb 2001
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From: n
I'm assuming you're talking about vacuum (in inHg) versus idle RPM.
Sorry to tell you, but there is no real way to "change" the vacuum, if that's what you're asking. If the porting killed that much vacuum, then there is nothing you can do except to replace all the ported housings, but I'm sure that's not what you're asking for.
There are other factors that affect idle vacuum. Most notable are intake vacuum leaks (which I think you have) and ignition timing. Double check to make sure ignition timing is within factory spec; if the ignition timing is off, vacuum will decrease - go figure.
Also, stupid stuff like loose spark plugs can affect idle vacuum.
-Ted
Sorry to tell you, but there is no real way to "change" the vacuum, if that's what you're asking. If the porting killed that much vacuum, then there is nothing you can do except to replace all the ported housings, but I'm sure that's not what you're asking for.
There are other factors that affect idle vacuum. Most notable are intake vacuum leaks (which I think you have) and ignition timing. Double check to make sure ignition timing is within factory spec; if the ignition timing is off, vacuum will decrease - go figure.
Also, stupid stuff like loose spark plugs can affect idle vacuum.
-Ted