2bar or 3bar?

[92BlkTy]

Looking at datamaster i realized that its showing readings of several PSI over stock. is datamaster able to read exact boost because i thought it only saw what the ECU sees. wouldnt that mean i have a 3 bar already since its going over 14.7? ive seen up to 16.8 on my DM files.

nevermind, i looked in another file and saw 17.6

 

[SY2932]

Unplug your MAP sensor and see what color the connector socket is:

"MAP sensors, stock 2 bar on left (orange/red connector) #16009886 and 3 bar on right (black connector) old number is #16040749 new # is #12223861." HTH's

 

[odium]

If the stock map sensor is a 2 bar, shouldn't it be able to read 29 psi since 1 bar = 14.5037738 psi? I'm confused now...

I have the orange plug and I can read up to 18 psi in datamaster (ATR Pitbull).

Why does the ultimate need a 3-bar? Does it expect people to be running over 30 psi?

 

[SY2932]

What’s a 3 bar chip and why is it better than a 2 bar chip?

To answer this question you must understand the ECM (your engine’s computer). Late model GM vehicles use one of 2 methods to determine the engine’s fueling needs: mass air flow or speed density. Mass air flow uses a sensor that actually measures the amount of air going into the engine, and from other data (engine speed, throttle position etc) can calculate the exact fueling needs. Speed density measures the manifold pressure, and its changes (along with engine speed and other related data) to meter fueling needs. On a naturally aspirated car (non supercharger/turbocharger) a 1 bar map sensor is needed, as the engine only operates in vacuum. The 1 bar map sensor can read from about 14.7psi vacuum (or negative pressure) to atmospheric pressure (0 psi). A 2 bar map sensor can read from 14.7psi vacuum to 14.7psi positive pressure (one bar vacuum, one bar pressure greater than atmospheric). In the same respect, a 3 bar map sensor reads from 14.7psi vacuum to 29.4psi positive pressure (one bar vacuum, two bar of boost pressure).

From: http://www.sportmachines.com/maintenance/beginner.php

 

[odium]

Aaah, thank you. So the way the MAP sensors are classified, 0 bar starts at 14.6 psi vacuum...

Why can I read 18 psi on datamaster if I have the stock 2-bar?

 

[jwaller]

Aaah, thank you. So the way the MAP sensors are classified, 0 bar starts at 14.6 psi vacuum...

Why can I read 18 psi on datamaster if I have the stock 2-bar?

bc the stock computer sucks and or you have the wrong value selected in datamaster for the map sensor