FACTS:
(1) I have calibrated a few stock map sensors, an Apexi 3 bar, and a GM 3 bar. The pressure gauge that I use is an expensive .5% error full scale 30 psi 6" gauge with 1 pound increments.
(2) My Blitz EBC has a built-in 3 bar map sensor for boost and max boost displays.
(3) The pressure gauge and Blitz pressure readings are dead on equal.
(4) With these I record what the map sensor/DL shows for PIM V and PIM ABS pressure with static pressure.
(5) When I log a 16 psi boost run in 4th gear it only takes about 12 seconds from 3500 - 7500 rpms. The DL recording for PIM V/boost is always lower under dynamic testing than static testing. The Blitz will show 16 psi but the DL shows 15.6 psi.

QUESTIONS:
(1) Is the low DL boost due to the DL being slow, or is the stock map sensor slow? I had read on a MOLAR site about their map sensor being slow.
(2) If you have an accurate boost gauge, what differential do you record with the GM 3 bar? I am trying to find a faster thus more accurate map sensor.

 

For a reaction speed test have you datalogged the stock vs test gage (if you have one with an analog out plugged into the DL) while ramping the test pressure? This would tell you what the response time comparison is.

Also suggest testing the stock map sensor with similar voltage to what the car runs at rather than battery voltage, you can do this by using jumper cables from a running car to your car's battery during the test.

 

After doing various boost testing/logging using my map calibration equipment, this is what I discovered.

My Blitz internal map sensor is a little too sensitive. When fast pressure increases are applied, it over shoots at first then settles down.
This causes the retained MAX BOOST values to be high. I was using this value to adjust my boost level. This problem tends to get worst at
higher boost levels. Unfortunatley, the Blitz display is in a location that would require a second person to view current boost while driving.
Which is what I will have to do now to set boost. The reason I do not use my AUTOMETER gauge for this: it's accuracy varies too much. It
reads from .5 psi high at 6psi boost to about 1.75 psi high at 16 psi boost.

This wasn't as bad of a problem with the stock twins in non-seq mode since they built boost slower with less flow. My GT35R builds boost
faster with more flow.

To help reduce the over reaction of the Blitz map sensor, I have now installed a pill in it's pressure hose. This did slow it down some.