Could a 3-4Hg drop in intake vacuum be caused by drastic elevation change? I live at 3800ft and when I go to sea level I gain 3-4Hg back. It's usually 16Hg at idle here but there its up around 20Hg...which is better spec I understand. I was willing to believe an intake leak until I made the trip twice just to make sure it always varied.

Any ideas?

 

The pressure is lower at higher altitudes so I think it's normal the vacuum would be a bit lower too. You loose about 3.5% power for every 1000' in elevation. I sure could use that extra 3.5% here in Kansas City (~1100').


Dave

 

I knew there was a rational scientific explanation Thanks man...it's much appreciated.