The numbers I mentioned are based on the WBC calculator taken from the wideband commander website

http://www.widebandcommander.com/downloads.htm

You have to take measurements with the ignition on and engine off and that will give you a voltage number at 0.0 zero psi. Now based on that number you get the other two numbers that I mentioned. So the numbers that I mentioned relate to what I got at 0 psi. Here they are again.

1.6 volts (ignition on engine off with GM 3 MAP sensor)=0 psi
0.00 volts=-14.67 psi
5.00 volts=31.18 psi

The 1.6 volts VARIES by atmospheric pressure. At my altitude I got 1.6 volts and therefore I got -14.67 psi=0.00 volts. Here is what WBC commander recommends you do to calibrate your GM 3 bar sensor

http://www.widebandcommander.com/techtips.htm

"The latest software download includes a "sensor calculator". Simply pick the sensor "GM 3 bar", and the appropriate data will come up. When you go into the analog set up in the WBC software, you'll enter this data. Since we all live at different elevations and thus have different absolute pressures, it's advised to get a "zero setting". Set the analog channel that is wired to the MAP sensor to display voltage. With the key on, engine off, record the voltage. This voltage should be entered in the sensor calculator to provide the software a proper zero reference."

The same process is recommended by Hondata, the famous Honda ECU tuner:

http://72.14.203.104/search?q=cache:...s&ct=clnk&cd=6

Check the wire voltage with a multi-meter to make sure the wiring has been performed correctly (alternatively HondaLogger can be used to datalog the voltage). With the ignition switch on but the engine not running the standard MAP sensor should read 2.85V between the MAP signal and GND wires. The GM MAP sensor should read 1.6V. (All voltages are correct for sea level - at higher altitudes the voltage will be lower.)

Again, I never mentioned Zeitronix by name. I AM TALKING IN GENERAL about calibrating a MAP sensor.

PLX also requires that you calibrate your MAP sensor.

http://www.plxdevices.com/AppNotes/

http://www.plxdevices.com/AppNotes/PLXApp013.pdf

You will notice that they list the MAP sensors that PLX uses including the GM 3 bar MAP sensor.

So what do we know so far? You will need to calibrate your MAP sensor when you use three out of four loggers, ie, Innovate, PLX, and WBC commander.

I stand by what I said that IN GENERAL you will need to calibrate your MAP sensor to use it properly.

 

So who is correct? These two quotes from Zeitronix users contradict each other

 

They do not contradict. They are both correct statements.

The EGT input is built into the ZT2 box regardless of what options.

To view and use the EGT input, you need the probe with ZT2 connector.

 

Mustang Dyno AFR unit

http://www.mustangdyne.com/AFanalyzer.htm