"""
 The MAP ports are just downstream from the TB.  The difference is that
 Tracy's TB is way out there BEFORE the runners.  Mine are about 5" from the
 rotor housing, and downstream from what are effectively short runners - the
 TB barrels.  I guess it could be that there is very short term variations in
 the MAP readings.
"""

Quite a few throttle bodies I've looked at had MAP ports right on them, just inboard of the butterflies.  That's where they are on the Eagle540, one right in front of each butterfly and teed together, then tapped off to the MAP sensor.  Works great on that engine, but it's got one of those humongous wrap-over and criss-crossed manifolds... I'm sure everything flow-related is pretty well smoothed out with 8 cylinders in the mix.  Just another data point.

    <Marv>