SimonSTI Posted July 2, 2020 Report Share Posted July 2, 2020 I've done a lot of reading and spent a few hours in the car doing some tests. Followed the guideline in the help file. Looking for ideas to help stabilize boost, currently chasing my tail. Can't seem to get the PID correct. Even with low number like P=0.2, D=0.1 it still overshoot at first then I have a few oscillation. With higher WGDC and P=1 and D=0.8 I had major oscillation from 15psi to 20psi. It's an EWG with base boost target of 200kpa/15psi. Testing at 220 for safety, end target would be 230. G25-660 on a destroke 2.35 with 9.3 compression ratio, spool pretty fast. Activating stage 2+3 end up doing some oscillation when stage 3 kicks in with only 0.1 for I value. Looks like stage 2 only works better or I didn't figure how to set it up properly. Reducing the WGDC at about 10-20% under the real target seems to help. Attaching a log with my latest setting (goes with Boost setup.png, P=0.6 and D=0.5). Also attaching another test I did with slighly higher WGDC and lower value on the PID. ECU Log 2020-07-1 115 8;55;46 pm.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 2, 2020 Report Share Posted July 2, 2020 Attach the tune please. Has the DC table been tuned in openloop first? It looks like in your pics above you need about 20%DC for 220Kpa but you have 14% in one table and 16 in the other. Quote Link to comment Share on other sites More sharing options...
SimonSTI Posted July 3, 2020 Author Report Share Posted July 3, 2020 here is the tune. Your right it takes about 20 to get 220kpa, but when I set the WGDC too close to the target it overshoot all the time. Simon-Gagnon-Subaru STI V10 G4X Xtreme Plugin-V1-3-3.pclx Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 3, 2020 Report Share Posted July 3, 2020 Set the wastegate DC table to whatever it needs to achieve the target boost in open loop. From your log it looks like 1% DC changes boost by about 5-7Kpa, so you are going to need quite small P. Try 0.1 initially. If you get overshoot then increase D, you may need top reduce stage 1 duty also. Do us another log with some of those changes so I have a feel for what direction to head. Quote Link to comment Share on other sites More sharing options...
SimonSTI Posted July 3, 2020 Author Report Share Posted July 3, 2020 Awesome tx for the info, really helpful. I did more test with the PID set to 0 yesterday to find proper WGDC. Here are the logs and the update values. I'll test some more today and post after. I want the turbo to get back to wastegate boost level ~200kpa pass 8k rpm, so I put the WGDC to 0 pass these RPM. Not sure it's the best way to do so, still testing. ECU Log 2020-07-2 123 9;31;21 pm.llgx Quote Link to comment Share on other sites More sharing options...
SimonSTI Posted July 11, 2020 Author Report Share Posted July 11, 2020 Update, I've been able to test a few more value tonight, getting there. Here is the latest setup and result with the log. Any comment welcome. Simon-Gagnon-Subaru STI V10 G4X Xtreme Plugin-V1-3-6.pclx ECU Log 2020-07-10 9;51;21 pm.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 11, 2020 Report Share Posted July 11, 2020 Get some integral gain in there now and that will close up that long term drift. Quote Link to comment Share on other sites More sharing options...
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