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View Full Version : What is Low/Med/High Baro? & a VVT ?



MN C5
November 2nd, 2007, 04:40 PM
Question #1

Help me understand what the he11 the baro settings are based on. Are these readings coming from the MAP? So is High Baro (high KPA?) ect...

Question #2 {B7934, B7935, B7936} factory settings for my L76 run from 0 values at idle to 14.5 @6500rpms. Is the cam fully advanced at 0 and retarded in degrees to 14.5 at 6500rpm ?

Thanks

Dennis

GMPX
November 3rd, 2007, 04:37 PM
The baro is calculated from the MAP.
High baro is sea level, low baro is high altitude. The thresholds for each stage are defined in the parameters section of the cam phasing section.

Cheers,
Ross

P.S - I logged at 3.6L V6 today and that had about 25deg cam timing on the intake cam.

MN C5
November 4th, 2007, 01:15 PM
Thanks Ross, just wanted to be sure... I tried a few different, bringing the #'s up and down. Improvements, if there any are far to diminutive for my SOP dyno. After playing with the settings I ended up leaving a copy of the low baro table pasted in the high baro table. Hard to tell any differences but it is smoother when AFM switches on. Power wise,,,nothing yet.

gmjunkie
April 12th, 2016, 07:48 AM
Hi Ross,

Sorry to dig up an old post, but I'm running into the same questions as the OP. I'm working on a 2013 Malibu 2.5L. What is the difference between the three tables? Is it literally referencing the barometric pressure outside of the vehicle (atmospheric) and determining whether it's high based on that, or is it referencing actual pressure (ex. 5% = Low Baro, 40% = Med Baro, 75% = High Baro) and comparing the Manifold Pressure to Atmospheric?

I've been changing the Intake Cam Phasing, and when I monitor actual phasing and compare it towards the table obviously the relationship is not direct. I know you said that the thresholds for each stages are defined in the parameters section... but lucky for me the only thing in the parameters section is a message that tells me there are two camshaft phasers (real helpful, huh...). So is there any chance you could provide the relationship towards what the readings are and actual camshaft phasing? Looking to understand what values I need to enter to adjust the timing in certain degrees, ex. 5 in the table equals 7 degrees etc.

Much Appreciated!