close loop boost control

[kevin p]

I got the boost set up in open loop. When I switch to close loop the boost was not hitting the target. I notice in the PID it had a negative value. I would think that is would be adding instead, I left the P at zero and I had the D at 4 % as it was losing boost in the high rpm range.

[Adamw]

"D" is effectively like "putting on the brakes" - it will pull duty cycle out based on the rate that you are approaching target. Stage 2 uses P & D only, stage 3 uses P & I only.  You will definitely need P.  

Will need logs and tune to offer any further help.  

 

[kevin p]

Hi,

 Can you switch the polarity on the boost solenoid without moving the wires?

 

Thanks

 

[Adamw]

A boost solenoid is just a coil of wire wrapped around an iron pole, they are not polarity sensitive and swapping the wires does nothing.  

What is the problem or what are you trying to achieve?

[kevin p]

raising the duty cycle lowers the boost, my question is can you invert the setup?

[Adamw]

You are probably better to fix the plumbing as working that way means if the solenoid fails or a wire breaks etc your boost goes to the moon.  

But if you want to invert the logic, change the "Active state" setting for the aux to the opposite of what it is now in the boost control settings

[kevin p]

thank you