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Been fighting getting this right for a while.
around 4800-5000 rpms it starts to diverge from everything i'm requesting it to do and just bleed power off and wastegate.
Now... I can use pressure differential under airflow -> pressure control to get desired TIP to go up, but it makes the truck close the throttle quite a lot to get it where i want it to be making the extra boost it's generating much less effective.
Here's a log:
Attachment 95874
Well you guys compare these 2 logs and tell me what you think i did. This isn't fixed in my eyes because of the throttle but tell me this isn't odd stuff.
Attachment 95925
The difference in these logs represents easily 100 whp.
So, I don't know how much the TB is affecting power in a force-fed setup, but the 2nd tune is kicking butt. If those engine torques numbers are accurate, then you are in the 540-600whp range up top... you have solid timing and airflow. Nice!
I'm interested to see what you did there.
Yes, the truck does make right at 600 whp on the 2nd datalog i linked.Quote:
Originally Posted by BBBm3
The issue i'm having is i can't find a way in the tune besides what i did for the 2nd datalog to get TIP desired to go up. Without TIP desired going up, TIP drops as i rev out making it stay right at 50 lb/min for some reason.
I can't find a good way to get TIP to go up besides throttle differential but that results in it closing the throttle.
This method is also semi inconsistent in power, it sometimes makes less power than other times.
Less as in timing/torque; I’m guessing? Care to post a tune or PM me one? It looks like driver demand is raised significantly, but I’m wondering if it’s something simple like increasing inverse engine torque where needed? I’m just brainstorming here and going off things that I’ve learned.Quote:
Originally Posted by w00t692
I've done that before, increased the inverse load values at the areas i was having trouble and it DOES have an affect on this problem. But it still fights it every step of the way. By doing that i can get it to basically drop to about 2.02 to 2.05 by 6k.Quote:
Originally Posted by BBBm3
If i do it this way, it closes the throttle on me but runs a load like i want it to.
So, I’m having kind of the same problem. I’m tuning on the street and it looks like you are on a Dyno, but I’ve just got into playing around with my 2020 raptor... BUT every time it closes the throttle in that ~4800rpm region too for just a second, then opens back up. It’s upsetting to say the least. I’m not exceeding LSPI tables, but it’s close. For some reason, my turbo airflow desire is differing. Also, my EWC is not following my commands exactly. So, I think that I’m having other problems.
This is a TIP calculation problem, and throttle differential helps to skew the TIP calculation in my favor, but that setting specifically closes the throttle so i definitely don't want to use it.
I just am not sure which value is causing my final tip result to skew lower as i pass 4800ish rpms.
Well, I?m definitely interested to see what you figure out. I?m having the damnedest time with this TB closure. On my 2019 (non HO), I did not experience this problem, and it?s basically the same tune.
Quote:
Originally Posted by BBBm3
That's the thing, 2018+ DO NOT EXPERIENCE THIS ISSUE at this airflow and i cannot find in the tune why they do not experience this. I'm not sure what's driving it.
Basically TIP Desired Max for Turbo Speed drives my TIP down and forces the truck to pull out a ton of wastegate to keep airflow right at 50 lb/min.
I cannot get it to stop doing this without a specific setting under airflow that seems to help skew the TIP calculation in my favor, but that then skews throttle opening out of my favor.
So, I was glancing a little bit. Under the TB tabs, can’t you start turning off the functions (Via 0 or 1) that control the TB to force it open? Again, I’m just brainstorming... I realize this is not the best fix, but it may work for the time being.
Popcorn airlimit
popcorn has shown up even when the load isn't limited and torque is met. Is it really?
In fact it always shows up at WOT basically.
It says it's limiting so something is up. You can disable this limit under throttle tab. Popcorn is responsible for may different unexplained tb closings.
That limit is disabled already. It's not that.
It's the fact that tip desired keeps dropping and tip actual follows it, driving power and wastegate down.
post your tune
Can you post how please?Quote:
Originally Posted by veeefour
Attachment 96263
Attachment 96264
Here's the cal and a datalog with this cal.
Note the MAP from desired airmass is just plain wrong. But here's the thing.
I don't have a clue what comes first in this equation.
I don't know if turbo speed desired forces it down first, if MAP from desired airmass is somehow wrong, if somehow TIP is driven down by something, or what!!
This is endless frustration for me because when i use throttle pressure differential it bumps MAP up, which bumps TIP up which "fixes" the problem, but then it's pulling throttle despite not meeting the desired load.
Something, in my opinion, is not exposed in the tune that i need access to to fix this.
My basis for this logic is that a 2018+ truck that has a larger turbo than a 17 does not have this problem. If i take one of my tunes that worked perfectly on a 19 truck, apply the same settings, it acts COMPLETELY the hell different right around where you see desired TIP and Turbo Speed nose dive.
I know 2018 turbos are not the same as CRP stage 3 2017 turbos, but they're very very close, the compressor wheels are not very different and the turbine wheels and wastegates are the same.
So, I don’t have my laptop on me, but have you edited the turbo/coefficient tables?
Absolutely.
Well increase this for starters - your map peaks around 2.3-ish BAR and you are only allowing LOAD to 2.1.
Your LOAD should equals MAP for best results.
Attachment 96304
I had that at 2.3 with no change in behavior so I set it back stock.
LOL set to 3 or even 4...as you can read it's labeled as MAX LOAD!
I had it at 3 as well and changed nothing.
It follows the LSPI tables.
Post a log with this raised to 3. LOAD clearly hanged around 2.1 exactly where it was limited.
It's clearly not torque related but rather load related. Very simple to solve if you follow the trend...
Attachment 96308
Here you go your tune was still limited in like 20 places - try this has to work.
Attachment 96309
I understand what you're saying. but i've done what you say to do, and it does not do anything at all. It trends down and the thing you're not looking at on your graphs for some reason is TIP actual vs TIP desired
If you note as you watch it, turbo speed desired is less, TIP actual is higher than desired and it keeps desiring less and less TIP, desired load is well above actual and desired airmass is high.
Did you figure this out for your record run?
Try rising the driver demand. I would change the predicted throttle angle and the effective area tables to force the TB to stay fully open. I also would rise the LSPI reduction tables to above 2.2
Any update on the issue?Quote:
Originally Posted by w00t692