Hello Guys
Im running into weird logging issue IDK if PR is defined correctly for NGC4 ecu 2010 SRT8 for some reason the PR value does not go above 1.0 under boost I can read 128KPA absolute base on the 82kpa Atm/Pressure that will put me in the 1.31PR value I attached a log.
Thanks
Have you increased the PRatio Max parameter in your tune, found under [Engine] [Airflow] [General] [Pressure Ratio Limits]?Originally Posted by GCtech
post your tune.
Calibration Attached with a recent Log as well
BTW the PR max is set at 3
You BARO sensor PID changes from 81kpa to 157kpa. I don't think it's supposed to do that...it should read around 100kpa and shouldn't change.
The PCM uses the BARO sensor along with the MAP sensor to calculate P ratio
(Barometric Pressure + Manifold Pressure) / Barometric Pressure = Pressure Ratio.
Is your MAP sensor data correct? It's been a while but IIRC, sensed MAP should be enabled and BARO learn should be disabled.
Hopefully someone else will chime in.
As the guys said, you have something funky going on with your baro readings. What map sensor are you using?
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The srt8 is not at sea level thats why Baro moves is 81-82kpa atomspheric pressure at were is currently located is 82kpa
Im using 3 bar map sensor all data is correct , there was a map limitation to 250kpa under engine diagnose max map but support already raised the limit, I thought that was causing it but it was not.
Thanks
That makes sense. However it shouldn't change. Turn MAP sensed on and Baro learn off and see what it does. With the BARO changing like that I can't see the PCM being able to calculate P Ratio correctly.
Ohh ok ok i see what you saying now it should stay at 82kpa all the time and not increase past 100kpa 1 absolute
I?ll turn Map sense and see what happens , i need to be able to do Baro corrections as altitude variates a lot from town to town down there just a 1.5hr drive will variate from 82kpa to 70kpa
If I turn Baro learn off wouldnt it cancel any Baro corrections as well?
Thanks
Baro Learn is used to update the ECU barometric pressure *during the current key cycle*. The ECU uses the MAP sensor in the manifold (the thing that reads your boost) to update its Baro as you drive... any time you get a throttle position that is near what it expects WOT to be, it will update its baro reading based on some maths... (air filter pressure drop, etc etc etc).
With a supercharger out there, it has no way to know that the pressure its seeing in from the sensor is the real BARO or if its boost.... It will go and update the baro to a bad value!
It's not *perfectly* ideal, but you are going to have to disable BARO learn, and let the short term adaptives work out the fueling changes based on elevation changes as you drive. the baro update from 82 to 70 (or the other way, from 70 to 80 to even sea level of 100kpa) shouldn't really cause any trouble for you, even if its not perfectly "up to date". those are still relatively small changes in overall air present. Just get the VE table dialed in and run with it... the car will just set its BARO on key "on" like it always does. This has been this way on these hemi's since we started tuning them years ago.
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Got it! I appreciate the input.
Thanks
You make any headway on this? Interested in the results.
I was having this same problem on 2007 6.1. Turned on Sensed map and Baro Learn off and its reading over 1.0 now.
What I know is, that the 3 Bar is not working correctly with non HC PCM?s
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