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Please post your most recent MSQ. The last version I found in this thread didn't even have boost control enabled.
Comparing your v.3 and your 95% duty cycle log shows me that you have a whole bunch of 60% duty cycle stuff going on. I am guessing your "bias" table is full of 60s, AND you are probably on setup mode with a boost control lower limit delta of 30 or so?
You are running open loop so "lower limit delta" doesn't apply.
I see this though...
See all those rows of 100%? Those are wasted. At MOST you want one row of 100% (and I am pretty sure you don't even need it).
Re-scale your open loop map similar to my bias table. You can't reach decent boost until about 3000 anyhow so that should be your first row. (you can re-scale the table by clicking on the little two arrow icon on the bottom left of the table).
My current bias table.
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What is your boost target? Nothing wrong with starting with open loop but you need to flesh it out a bit. By looking at your logs, 60% duty cycle at 4,500 is about 11psi. Start raising your 100% throttle duty cycles prior to 4500 and see if you can hit 11psi earlier.
What is your boost target? Nothing wrong with starting with open loop but you need to flesh it out a bit. By looking at your logs, 60% duty cycle at 4,500 is about 11psi. Start raising your 100% throttle duty cycles prior to 4500 and see if you can hit 11psi earlier.
First, thank you for your help. I appreciate it.
Im shooting for 10-10.5 psi. The 11psi is because the last time I messed with the duty table it was warmer out so I didn't account for the temp change which made more boost.
Im a little confused when you say "Start raising your 100% throttle duty cycles prior to 4500 and see if you can hit 11psi earlier." because if 100% is all the way closed on the EBC, how will it spool up any faster than it is?
On your open loop screen the y axis is throttle open percentage.
rescale your table so that you have one row of 100% duty all the way from 0% throttle until 100%.
Then, set the 100%-80% throttle values at each rpm increment to 60 to start if it's not already. do this until about 5,500 rpm on the table. Then, do a pull. Increase the 100%-80% throttle duty cycles by 3% or so until you hit 11 psi in that rpm range on the street. If it goes a bit too high, pull some duty cycle percentage.
On your open loop screen the y axis is throttle open percentage.
rescale your table so that you have one row of 100% duty all the way from 0% throttle until 100%.
Then, set the 100%-80% throttle values at each rpm increment to 60 to start if it's not already. do this until about 5,500 rpm on the table. Then, do a pull. Increase the 100%-80% throttle duty cycles by 3% or so until you hit 11 psi in that rpm range on the street. If it goes a bit too high, pull some duty cycle percentage.
Perfect! Thank you so much. This made 100% sense.
Now, once I have the 80-100% dialed in, I just fade it down to 0% correct?
Here's how mine looks like. I reach my target 14 psi at 2900 rpm, so I am catching it a bit earlier. 80-100% throttle afterwards is just to maintain your target. All other values is for spool up and response in everyday driving. Bear in mind that your turbo may need different numbers to maintain target. Volvo turbos for example need lower duty cycles as rpm increases.
Keep in mind that I am bottle necking my exhaust right now with the stock 2.25" mid pipe. I can't afford a full 3" system at the moment and I am still undecided on what mufflers and whatnot I want to get. So Im sure that is a huge reason why my spool is *** right now.
That was kind of random but for those of you who didnt know and were wondering why it was spooling up so late thats why. Well, at least a big part of the reason.
Here's how mine looks like. I reach my target 14 psi at 2900 rpm, so I am catching it a bit earlier. 80-100% throttle afterwards is just to maintain your target. All other values is for spool up and response in everyday driving.
So how did you figure out what numbers to put in the middle of the table. Like, what were you looking for in your logs?
Go full throttle and dial it in to reach 10.5psi or whatever. Write down those numbers. Then lower the duty cycles to hit 8psi for example. Once you have those numbers, paste them into the 60-70% throttle areas and bring back your 10.5psi numbers. It's not going to be perfect but the idea is to have gradually more boost with more throttle.
Keep in mind that I am bottle necking my exhaust right now with the stock 2.25" mid pipe. I can't afford a full 3" system at the moment and I am still undecided on what mufflers and whatnot I want to get. So Im sure that is a huge reason why my spool is *** right now.
That was kind of random but for those of you who didnt know and were wondering why it was spooling up so late thats why. Well, at least a big part of the reason.
As rpm increases, less duty was needed. For example going 3000 rpm having 100% duty cycle means I want the turbo to spool fast because flow to the turbo is at a lower level. The turbo easily spins by 4000, so high duty there and your turbo will spool so quick you will overshoot your target.
Why are you spending so much time on open loop. Start with closed loop.
^^ my overall feeling as well.
the only reason I didn't say anything was because you could take your open loop numbers to reach "x" boost and use them to start to populate bias table.
The guy was looking for help setting up his boost. If we are going to tell him to set up closed loop boost maybe it would be helpful to actually help him? I don't know exactly the best way to set up a bias table. I kinda fumbled around until I got something that kinda works.
Here is a my best effort:
- Change mode from "open loop" to closed loop.
- Set "Lower limit delta" to something like 30kpa
- Make sure you are on "setup" mode rather than "basic" or "advanced"
- Open boost targets table in the boost control menu. Your x-axis is RPM. Set that to be something close to the same RPM numbers I gave earlier. Your y-axis is throttle position.
- For now, set 80-100% throttle to be 150kpa.
- Open your "boost bias" table in the boost menu. Your x-axis is again RPM. Set it to the same RPM increments as before. Your y-axis is KPA target.
- for now, set up the y-axis to start at 150kpa and go up in 10kpa increments. We can always re-interpolate later but that will get us started.
- For EVERY cell in the map at 170kpa and above set the duty to 60% We "kinda" know that it's a decent starting point so we can at least do that.
- For 150 and 160kpa rows, set duty to something low like 30%.
Now, what will happen when you accelerate at full throttle is that the ecu will look at the boost target table and see that your target is 150kpa. The ECU will keep the boost controller at 100% duty until the car gets to 120kpa (boost target minus lower limit delta). Once it gets to 120kpa, the ECU will look to what the boost duty cycle should be on the boost bias table. That may or may not achieve your target 150kpa.
What your goal is now, is to do full throttle runs, adjusting the boost bias table in the 150kpa row to ACTUALLY achieve 150kpa.
Once you get close, Change your boost target map so that 80-100% throttle targets 160kpa. Repeat the above procedure. When done, do the same for 170kpa.
Once your boost bias table is complete you can switch over from "setup" mode to "basic" mode or do whatever everyone else here suggests. I am NOT an expert at closed loop. I am still muddling around with it, but the above proceedure should get you close and is necessary to move on to basic and advanced modes.
Read those 3 threads and then come back and ask more questions.
Chiburbian posted some good info. But I'd like to add one thing.
Now, what will happen when you accelerate at full throttle is that the ecu will look at the boost target table and see that your target is 150kpa. The ECU will keep the boost controller at 100% duty until the car gets to 120kpa (boost target minus lower limit delta). Once it gets to 120kpa, the ECU will look to what the boost duty cycle should be on the boost bias table. That may or may not achieve your target 150kpa.
The ECU will be looking at the bias duty table any time you are above the boost target minus lower limit delta. This allows you to handle cases where you need more duty to keep the boost flat as rpm's rise. And it also takes some load off of the PID calculations.
In setup mode your Boost Duty will follow the bias table exactly, so get it nailed down there, then switch to Basic mode.
In 1.4 PID is only used to correct for changes in weather or other small factors, the bias duty table handles the mechanical changes that require different amounts of duty.
02-09-2017, 08:48 PM
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