GM 1bar MAP will it see any boost?

[soren]

>If you mean to do any meaningful calibrations at several PSI of
>boost then you should be running a 2 bar MAP sensor (which
>will work up to 14.7 PSI of boost).  More than 14.7 or so then
>a 3 bar that takes ya up to 29.4.

    I agree that you should have the correct sensor and ECM calibrations for
the amoutn of boost you are planning on running.  However, some turbocharged
vehicles using Delco ECMs that also use the 2 bar MAP sensor are set up to
richen the mixture way too much when you max out the MAP sensor.  For
example, running 14 psi on one a 91 Impulse results in the computer dumping
lots of extra fuel into the cylinders.  Bumping the boost up to 17 psi sends
the exact same MAP signal to the ECM as 14 psi, but relults in a proper
air-fuel ratio.  I guess that takes advantage of the old "built in safety
factor".

Soren Rounds