Closed loop boost control for XEDE
Closed loop boost control for XEDE
Well Guys,
I know that it has been mentioned that the XEDE can control boost in a closed loop fashion. However, the MAP sensor on the EVO is a 1 bar unit (I still cannot figure why that is). I was thinking that the closed loop system could be made to work with the MAS sensor in the car since this already a parameter that is monitored. This would allow continuous compensation for temperature since the density of the air would be greater at cooler temperatures and less at warmer temperatures. In my mind, the set point would become a MAS value at a given RPM. I would think that this would give a more stable tune, quicker spool and give a temperature compensation (i.e. no more boost cut).
The disadvantage to this type of system would be that your actual boost pressure would vary according to temperature. However, it would automatically decrease boost at colder temperatures and increase it at warmer temperatures. If you think about boost, we are really not trying to maintain a pressure, we are trying to maintain a volumetric efficiency. This may be the answer.
Do you guys see a problem in operating in this manner if it was implemented. Shiv may be the only one that can comment on this, but I would like to get some feedback from you guys.
I know that it has been mentioned that the XEDE can control boost in a closed loop fashion. However, the MAP sensor on the EVO is a 1 bar unit (I still cannot figure why that is). I was thinking that the closed loop system could be made to work with the MAS sensor in the car since this already a parameter that is monitored. This would allow continuous compensation for temperature since the density of the air would be greater at cooler temperatures and less at warmer temperatures. In my mind, the set point would become a MAS value at a given RPM. I would think that this would give a more stable tune, quicker spool and give a temperature compensation (i.e. no more boost cut).
The disadvantage to this type of system would be that your actual boost pressure would vary according to temperature. However, it would automatically decrease boost at colder temperatures and increase it at warmer temperatures. If you think about boost, we are really not trying to maintain a pressure, we are trying to maintain a volumetric efficiency. This may be the answer.
Do you guys see a problem in operating in this manner if it was implemented. Shiv may be the only one that can comment on this, but I would like to get some feedback from you guys.
I had a similar idea/question. See the following post. https://www.evolutionm.net/forums/sh...threadid=65671
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Closed loop boost control is completely do-able given the current hardware. As Autoxer mentioned, it can be done quite accurately using calculated boost by comparing at MAF and RPM. However, it will have to wait for a little bit. We finally got the new firmware wrapped up last week and running in cars all over the US without a glitch. We're currently working on the tuning module with knock logging. I'll try to get the closed loop boost control feature implemented along the way since I don't think it will be exceptionally difficult to do. We'll see.... 
Shiv
Shiv
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The Evo's MDP sensor is only 1 bar because it only measures vacuum. It is also an MDP sensor, or manifold DIFFERENTIAL pressure sensor, not a manifold ABSOLUTE pressure sensor.
The MDP sensor is used to check whether or not the EGR valve is opening correctly. It is purely an OBDII check related sensor.
The MDP sensor is used to check whether or not the EGR valve is opening correctly. It is purely an OBDII check related sensor.