Originally Posted by
sprinto7
I realize this is an older thread, but I want to add something. I have experience with the E78 as used on the GM 1.4 Turbo engines. The 2011 Cruze "DOES" have an external Baro sensor. The 2012 on up has the Baro sensor in the MAF that is located in the air filter "box." Is it possible the same thing applies to E78 use in the V8 vehicles.
I'm still not sure just what the Baro sensor does with the tune. I know the VVE is laid out with baro/map pressure ratio rows and RPM columns.
My 1.4 vehicle runs in SCCA autocross and is required to use a 33 mm restrictor in the turbo inlet air tube. I run the MAF after the restrictor and have noticed the baro reading will go lower at high airflow rates. I assume this is caused by a restriction of air flow by the restrictor, OR, a restrictive air filter.
I am currently running in SD open loop mode.
Suggestions would be greatly appreciated.
Del Long
2019-11-21
I've done some further testing, by removing the air filter, running car down 300 foot driveway and the log shows the baro pressure still drops from 14.2 to 8.5. Remove the 33mm restrictor and the baro only drops to 14.1. So, it is the restrictor that causes the drop. I think this is normal, and that is what a turbo that is capable of flowing more CFM than the restrictor will allow will do. Now the question is, "Just what is this baro sensor reading used for"?
Del Long