Logged boost vs mechanical boost.

Mikey52

Active member
Sep 20, 2018
173
43
28
KOEO THE MAP SHOULD BE CLOSE TO 14.7 but needs to be corrected to altitude above msl, boost should be zero.
 

N2BRK

Well-known member
Dec 31, 2009
2,391
727
113
Ok. What about location. If you have a boost leak, and the sensors are far apart, could we get this discrepancy under load? Boost leak test next?
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,875
979
113
Texas!!!
Ok, lets start over. Is your CTS reading off across the board, or is it only off at full boost? I can tell you the stock MAP sensor is only 2.5 bar (approx 36 psia). It generally maxes out around 22-23 psig (it will read a little higher at lower barometric pressure). If it is reading off across the board, the sensor isn't scaled correctly in the tune. If it is only off at max boost, your just saturating the sensor.
 

darkness

Well-known member
Jul 15, 2009
1,573
597
113
49
vegas
Ok, lets start over. Is your CTS reading off across the board, or is it only off at full boost? I can tell you the stock MAP sensor is only 2.5 bar (approx 36 psia). It generally maxes out around 22-23 psig (it will read a little higher at lower barometric pressure). If it is reading off across the board, the sensor isn't scaled correctly in the tune. If it is only off at max boost, your just saturating the sensor.
From the beginning.
I only have actual numbers based off of max boost. Pulling my trailer out of town, climbing a hill, my cts3 monitor was reading 24psi, which is right on based on the tune which at approximately 80-85 mm3 fuel at 2200rpm puts the psia that the boost table is written in at 35.4-36.6. While the mechanical gauge (psig) was reading 35+. And I’m sure it’s 100% pure coincidence that it’s reading close to what the boost table (psia) is at.
As far as I know, it is a stock map sensor.
In my log, I’m certain I have the wrong PID for boost. It’s not calcactboost like it should be.
 

darkness

Well-known member
Jul 15, 2009
1,573
597
113
49
vegas
Studying more of my log, I’m leaning towards MAP is bad. Sorry to put everyone thru this. I’ll update when I get it put in.