So I just got my ScanGauge today, and after digging a little, I thought perhaps the XGauge feature could be used to calculate approximate boost vs. the Manifold Absolute Pressure that's available as a standard gauge with it. I posted in another thread and emailed Linear Logic probing for the method to do it. Then I found
THIS POST on the TDIClub forum - exactly what I was looking for - and it WORKS!
Atmospheric pressure starts at 14.7psi at sea level, and drops approx. 0.5psi per 1000 feet of elevation...
For 14.3PSI atmospheric pressure (about 800 ft elevation):
TXD: 68 6A F1 01 0B
RXF: 04 41 85 0B 00 00
RXD: 28 08
MTH: 00 91 00 64 FF 71
(note - you don't enter the spaces - they're just to make it reading-friendly)
For other pressures, just substitute the following for the last four characters of the MTH string (replace the FF 71):
12.0 -- FF88
12.1 -- FF87
12.2 -- FF86
12.3 -- FF85
12.4 -- FF84
12.5 -- FF83
12.6 -- FF82
12.7 -- FF81
12.8 -- FF80
12.9 -- FF7F
13.0 -- FF7E
13.1 -- FF7D
13.2 -- FF7C
13.3 -- FF7B
13.4 -- FF7A
13.5 -- FF79
13.6 -- FF78
13.7 -- FF77
13.8 -- FF76
13.9 -- FF75
14.0 -- FF74
14.1 -- FF73
14.2 -- FF72
14.3 -- FF71
14.4 -- FF70
14.5 -- FF6F
14.6 -- FF6E
14.7 -- FF6D
14.8 -- FF6C
14.9 -- FF6B
15.0 -- FF6A
Huge kudos for seftonm over there for finding other smart guys and working this out!
UPDATE:
Thanks to Tu13es for being persistent - the Linear Logic guys came up with a solution for the R55/R56/R57 issue that required MAP to be displayed also.
On the R56 - use TXD of 07DF010B instead!
