Math question? PSI to inHg
 

I found a conversion factor of .4912 to convert in. Hg to PSI, and 2.036 to convert PSI to in. Hg.

I just want someone to verify what I'm thinking.

-10.6PSI = 21.58 in. Hg vacuum?

If so my Map sensor is working correctly, my Boost gauge is either screwed, or I may have a small leak in the vacuum line feeding the boost guage.

My boost guage reads low on the vacuum side if my above math is right.

The -10.6psi comes from Hau's emanage tool, and looking at the Support Tool data logs the Voltage seems to corrispond.

I'm thinking I have a small vacuum leak just before my boost gauge.

This is FUN!

Jay

Probably different readings man.
Your boost gauge is reading vacuum relative to current atmospheric pressure while your MAP is reading it relative to 29.92" Hg
Hence the map would read more vacuum.

So the MAP sensor is showing me the accurate reading then. The boost gauge will be accurate in refrence to current atmospheric pressure. So if I were to drive down to sea level my vacuum and boost would shift and match the MAP sensor.

So I'm only really boosting 7psi, but my vacuum reading is more inline with the normal 21-22 in.Hg. Guess I need to fix the leaking exhaust manifold gasket. :)