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Ba open loop boost control


will15
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Why can’t I get this ba into open loop boost, I have done a couple of fgs that work really well and used the same method  on this car but it’s  either 100% dc or 0 I think the open loop over and under scalers are giving me this problem. Any help

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Sounds like you answered your own question!

Underboost will give you 100% duty, overboost will give you 0% duty.

I bet your underboost threshold is higher than your overboost threshold so there is no actual zone in the middle where open loop occurs.

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Boost error = desired boost - actual boost.

So log your boost error vs your desired boost then compare it to the two thresholds and the problem should be fairly obvious then. I'm 99% sure this will be your problem.

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Is there a way I can run solely off the waste gate dc table and not have any under boost or over boost, then set up  desired boost table just for  overboots situation protection. This is what I have done for the fg’s And it works great.

Edited by will15
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23 hours ago, will15 said:

But I’m running open loop I don’t ever want it to look at under boost and whack 100%dc 

So set the limits out of range. Eg make the underboost threshold very low.

Why don't you want to use it? It helps spool the turbo at part throttle much faster.

You can just change the underboost duty cycle. There is a scalar which will have 1 in it, change it to 0.6 for 60% duty when in underboost if you want.

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Closed loop is PID control which is completely different. What the Ford has is open loop + and on/off controller which is the over/underboost thresholds.  Closed loop is only used when you are within a few kpa of setpoint and it will use a PID controller to keep it there, unless your desired boost matches very closely what you see in open loop exactly chances are it won't activate.

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Hey Roland just getting my head around how the system works can you confirm the following 

the car uses open loopDuty Cycle from idle up until it reaches its set point ? at what point does it then change to reference and use the Desired boost Map ? is  the Ford Open loop the same as after market boost controllers Eboost or similar and is the Duty cycle table set that 1 is waste gate closed and lower numbers are opening the gate with 0 being waste gate completely open. Does the car then adjust it fueling for AFR on set table Auf0172 which is in  Lambda 1 =  14.7AFR  if the boost preassure is raised via Openloop duty cycle the car will self adjust based on the set AFR in table Auf0172 or are there other tables that need to be adjusted obviously timing needs to be checked also for detonation.

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Have you read the HOWTO guides?

Regarding open loop fuel control read this guide. These cars only have a narrow band sensor so there is only closed loop fueling at 1.0 lambda, every other figure will be open loop only and will mean the speed density and injector slopes need to be perfectly dialled in, if they are not then the figure in the base fuel lambda table will not match what is actually happening in the engine.

Read all of the HOWTO guides, these questions should be able to be answered from these.

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