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Waste gate DC% =0 for open loop boost control


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Hi.  I'm sure I've missed something simple here, but I can't seem to get the Waste Gate DC% to go above zero.  The actuator itself seems to work when in test mode, but when driving the car I can see the WGate DC value is zero the whole time, even when all the conditions to turn on open loop boost control are satisfied (I think).   The boost level I am seeing also indicates the waste gate remains closed. 

Boost Status goes from Off to Open Loop while driving, but WGate DC remains at zero.   

The help file referrers to Boost Status having more states than this, including RPM Lockout and Map Lockout.  I can't see these states when scanning my log file.  (my RPM activation was set to 200, so RPM Lockout will never show, but MAP Lockout should).   Something's gone wrong! 

ECU: G4x Storm

Firmware Version:  6.16.15

PCLink version: 6.16.26

 

Attached is a short log and calibration file. 

Thanks in advance.

map_11_openloop_boost_test.pclx open loop boost test.llgx

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Yeah, Im not really sure, I would suggest updating to the latest firmware to start with.  I loaded your map into a ECU with current firmware and it works fine in my quick test below.  But I did also try the oldest firmware I had handy (6.16.27) and it still worked fine in that too so Im still not convinced if that is your problem or there is something else Im missing too.  Note you should zero out your trim tables as some of them are adding 100% when the temps and gear is high which is why it shows 100% DC below.

Give us another log at idle on current firmware if it still doesnt work and I will take a closer look.

bXyj0wH.png

 

 

1 hour ago, RobinHodges said:

The help file referrers to Boost Status having more states than this, including RPM Lockout and Map Lockout.  I can't see these states when scanning my log file.  (my RPM activation was set to 200, so RPM Lockout will never show, but MAP Lockout should).   Something's gone wrong! 

Yeah, I think the help file is wrong there but I will get that clarified.  For me if Im below the RPM or MAP lock out the status shows OFF rather than MAP lockout.  

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Thanks Adam.  Leaving in the trim values of 100% in some places is my mistake. I was playing around with those to be sure they do what I expect once I saw the DC was 0. (i.e. do they add? - in which case I wanted them at 0, or are they multipliers?  - in which case I want them at 100%.  Looks like they are adders. )

I'll grab a log at idle in a couple of hours. Cheers. 

  

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OK I've just got back from running a test closed loop. The behaviour is similar to the open loop case in that the WasterGate % DC 1 table does not seem to get added into the outgoing wastegate DC command to the valve control (i.e. this feed-forward term is ignored, and I'm only running on the stage 1 spool up then the PIDs). 

Boost target was a constant 180kpa.  WasterGate % DC 1 table was 50% all over. 

The PID behaviour looks ok (first time I've set this up, so of course it's not optimised).  So in both open loop and closed loop cases, the values in the WasterGate % DC 1 table are ignored. 

Calibration file and log file attached. 

Thanks!!

 

180 target dc 50.llgx map_13_closed_loop_boost_test.pclx

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12 hours ago, Adamw said:

Give us another log at idle on current firmware if it still doesnt work and I will take a closer look.

 

Can you please update to the current firmware, you are still on old firmware in your latest map.  It should be 6.17.8

 

XvKNSTu.png

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12 hours ago, RobinHodges said:

The help file referrers to Boost Status having more states than this, including RPM Lockout and Map Lockout.

The current release and prior have only off and openloop statuses when using open loop boost control, this has already been improved to have the lockouts also displayed in open loop boost control and will be in the next release (should be available soon).

 

10 hours ago, RobinHodges said:

i.e. do they add? - in which case I wanted them at 0, or are they multipliers?  - in which case I want them at 100%.  Looks like they are adders. )

they are percentage multipliers, e.g. 40% in the table and and ect value of 50% will result in 40*(1+(0.01*50)) = 40*1.5 = 60% (as per the help manual, target trims are offsets and wastegate DC trims are percentage multipliers).

 

I can't see any reason why it wasn't giving you a duty cycle but I am looking at much newer code which will have had multiple improvements and fixes made to it . I would strongly recommend updating to the newest PCLink and firmware available.

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Hi guys. 

So I've updated the firmware this evening on my G4x Storm (version 6.17.8), and also PC Link (6.17.22). I repeated the open loop boost control test. 

Sadly WasteGate % DC 1 is still showing 0% even though boost status switches to "open loop" once MAP and rpm constraints are met. 

This isn't just a display issue.  The boost pressure achieved is the same as with boost control turned off completely. 

Attached is the calibration file and a log file (zipped due to upload file size constraints).

Please can you shed some light on this for me.  Clearly I'm missing something simple here!

Are you able to test my calibration file on a G4x Storm with the same firmware?

Thanks! 

map_13_open_loop_boost_control_wastegate_dc_50.pclx open loop test 1.zip

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Yeah, your map works ok for me.  I suspect possibly the wastegate table has not originally initialized properly and has some part of it that is not working correctly.  Can you go to boost set up, change boost mode to off, do a store.  Then change boost mode back to open loop and when the dialog pops up that says "do you want to clear watsegate DC table to all zero and set axis to default...", choose yes.  This will re-initialise that table.

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Hi Adam.  

Thanks for the tip! It's working, but I think I've found a bug / interesting behaviour with my setup.  

After re-initialising the table, it sets it up as a 3D table (with RPM and MGP(or MAP?) as the axis).  Filling this in with waste gate  DC values worked.  The actuator pulses.

I then made it a 2D table (RPM only) then it stops working. It seems you NEED the second axis. 

I'm happy enough with the 3D table - but it would be good to understand what's going on here. 

What I did notice is that when you go from the 2D table to a 3D table (press X and add the pressure axis), the 3D table top row is filled in with the DC values from the 2D table, and the rest of the 3D table is 0.  The running point on the pressure axis is such that the 0 values are being accessed. Then of course when you set the whole table to non-zero values at the running point, its working.

This implies that the 2D table I'm looking at is actually the 3D table, but only top row showing? (with the rest of the tale = 0, hence my DC values are not working).

Thanks, Robin

 

 

3d table filled in with DC values working ok.PNG

3d table top row filled in no DC values at running point.PNG

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