How is boost being commanded?

[ZMB]

Full disclaimer I am new to falcon PCM tuning although I have had some experience tuning some standalone ECU's and piggbacks in the past on the street.

I cant seem to figure out how the tune on my car is commanding boost.

The AUF16463 open loop duty cycle is set quite low across the whole range

The AUF16459 target boost table is set to 13.8 the whole way through (which im sure would be causing boost error values as it cant get that boost everywhere)

The AUF0511 boost sensor volt max has been set to 12v, I understand 4.8/4.9 is the recommended maximum to still retain boost safety so this has been disabled.

The AUF1098 Boost error to activate P1227 was set to -43.8 instead of the stock value of -2.5
When I set this value back to stock and go for a drive I basically just get little to no boost so I assume this is triggering P1227 due to the fact that that AUF16459 is requesting impossible values at certain RPM.

 

My question is, what on earth is controlling the boost if the open loop duty cycle is so low and enabling the boost error safety causes it to go to open loop only?
What should I be looking at because the car makes between 14-16psi depending on the day. Is it just that the desired boost tables are set stupidly and they have disabled the safety because of it? Can I just tweak that table to some more realistic numbers and re-enable the AUF1098 to a more suitable value?

I want to re-enable the safety measures and correctly control the boost using the guides listed here but to try and make sense of what has already been done to the tune by the previous owner is doing my head in. I need to replace the turbo and want to make sure I have a good understanding of what is controlling it before I change anything.
 

I appreciate the time anyone takes to assist, or if this is better as a paid service please DM me?

HAEK2KC.tec

[hjtrbo]

Follow and execute the open loop tuning how to will give you a very good step up from where you're at. I only looked at the turbo part of your tune, not much has been touched so you haven't got much to change. 

As a training exercise I suggest returning your turbocharger section to stock, then follow the open loop how to.

[ZMB]

Thanks mate, this is more or less the confidence boost I needed to get stuck into it.
I just wasn't sure if there was something I missed before reverting stuff back to stock. Probably being over-cautious but ill go back to base and start learning with the guides.

[hjtrbo]

Don't go stupid on the boost. You'll need to muck with timing and fuelling if you do. Keep it around the stock boost level whilst you're playing / learning to be safe.

[ZMB]

I know the tune is safe for the current boost level so ill be saving a copy of it in its current state, then reverting it back to stock and seeing if I can target the same numbers with the existing turbo by following the how-to guides so I dont have to worry about other factors. Then change the turbo over once I have confidence in my ability to control it properly and keep an eye on the vitals, Ive got a wideband and knock ears.

I am only going from a 3576 to a 3582 so I am not going nuts with it....just yet. I'm looking forward to getting to know this software well, its fantastic so far.

[BeerTurbo]

On 11/16/2023 at 8:51 AM, ZMB said:

Full disclaimer I am new to falcon PCM tuning although I have had some experience tuning some standalone ECU's and piggbacks in the past on the street.

I cant seem to figure out how the tune on my car is commanding boost.

The AUF16463 open loop duty cycle is set quite low across the whole range

The AUF16459 target boost table is set to 13.8 the whole way through (which im sure would be causing boost error values as it cant get that boost everywhere)

The AUF0511 boost sensor volt max has been set to 12v, I understand 4.8/4.9 is the recommended maximum to still retain boost safety so this has been disabled.

The AUF1098 Boost error to activate P1227 was set to -43.8 instead of the stock value of -2.5
When I set this value back to stock and go for a drive I basically just get little to no boost so I assume this is triggering P1227 due to the fact that that AUF16459 is requesting impossible values at certain RPM.

HAEK2KC.tec 980.69 kB · 1 download

AUF16463 - for fun you can use basic math to try get it in the ballpark, but there are a lot of mechanical factors at play... so say you have a 7 psi spring and you want 10psi, 10/7=1.42...so in theroy you need about 0.42 of boost control to get your desired boost. now remember what i just said, theres a ton of mecanical factors at play and you see the table goes through ll the temp , as that plays a big afect to. leave closed loop boost control on, data log and see how close the boost error and wg duity are.

target boost table can be whatever you want. 13.8 is measured in inhg, so its commanding 6.7psi. personally i like to slow ramp the boost in around 2000 rpm range and ramp into boost around 3k. it would be advisable when playing to play in the higer areas anyway you dont want an overboost to runaway on you. you will notice there is a temp value here to, so i like to target gate pressure when the air is hot, like over 75 degrees or so.

leave every thing else standard while your playing and have done a few data logs to understand how its all plays out.

actually thats wrong, change your under boost duity cycle from 1 to whatever your higest value in your closed loop table is. for me with a 10 psi spring, if it goes overboot and hits one it could try smash 20 psi in? if you follow.

 

[ZMB]

Could I get a sanity check on this datalog please?

I seem to be getting control of the boost up until a certain point, if I set desired boost to 10psi I get 10psi. (on an external boost gauge)
If I force it into open loop I seem to have good control over the boost with the Open Loop WG Duty Cycle map, except I seem to hear the solenoid pulsing constantly even when the engine is off but power is on so I might have done something wrong there.

When it is in closed loop, it does what it is told until 4000rpm and then it just seems to shut the wastegate and feed it as much as it can. I am trying to track down the source of this but when I tried to get a log for this I noticed that the Desired Boost target was 0 and never changed but the Desired Boost Error is reflective of what boost the car is making.

to get the vehicle to make any boost at all without going into limp/protection the auF1098 scalar has had to be adjusted.
This was already set to -40 in the tune that was on the car before I changed anything and ive set it to stock and run into issues.
I had to set it to something greater than stock to get it to make boost without going into limp mode/protection

Have I uncovered a larger issue? Good god am I confused.

05-12-2023 04-44-44 PM Log.teclog

[Puffwagon]

Looks like boost creeping based on reading the post. This is caused by the wastegate not being able to bypass enough air.

As a diagnosing exercise make your wgdc table 0 from 4000rpm onwards and leave the desired boost at 10psi. Alternatively you could make the last column 0 and interpolate it from 3500rpm to give a gradual duty cycle drop off, while leaving the desired boost as is.

I'll have a look at the log later when I get a chance.

[BeerTurbo]

desired boost of 10 is 4.9 psi because its in INHG.

in your log your duty cycle is 0 as your boost error is huge out of the get go.

 

your hitting 20 psi and a bit of timing are you running e85? i hope so.

you have more of a mecanical issue to diagnose before playing with the boost controler. bypass the boost controler and data log the boost you get. thats your baseline

[Puffwagon]

Ok I can see the gate duty cycle is already 0 with the boost climbing up to 22psi or so.

The tune that has been posted at the top isn't the tune that was used to get the log or at least the picture, so neither are much help. I did have a quick look at the tune however and despite it needing changes, nothing tells me that it's causing the boost to go crazy.

More than likely you have a mechanical issue, could be a stuck flapper or a hole in the actuator diaphragm.

[ZMB]

Thanks guys, your input is invaluable and appreciated.

So no I am not running E85, I have only done two WOT pulls on the car in this condition. Once when I noticed the over-boost and once to log it, so that wont be happening again until things are figured out. I would have only done one pull but my assistant is my 12 year old son and we missed the first one 🙃

I have a few things to look at based off your suggestions.
The turbo is a brand new Gen1 GT3582 that ive had unused for a while, it has a new IWG75 with a 7psi spring in it.
I set the preload on it, I checked the movement of the flapper before I installed it. But I did not test it with a compressor to confirm complete movement of the actuator.
Its not ported either so I would assume this would be causing some over-boosting as well, but I did not expect to see such an extreme case.

I will take the turbo off, test the actuator fully before I get any baseline readings moving forward.
I will probably see if I can find someone to do a flapper mod and porting on it while its off too then report back with some more results.

[Puffwagon]

Here's a handy bit of info regarding a stock wg hole. With no actuator in use and the hole wide open, you'll make no boost until around 4500rpm then it will start climbing and make around 10psi by redline. You chuck a 7psi spring on top of that with the flap connected and you've got 17psi with no duty cycle, add a bit of preload and you can easily make over 20psi with no duty at all. With a TS actuator you want the preload to be absolutely minimal ie: the flap is barely sealing the seat.

 

23 hours ago, ZMB said:

I seem to be getting control of the boost up until a certain point

 

Most of the time you will start losing control of the boost after 4000rpm which can be seen by the dropping duty requirements. Is this in line with what you're seeing? At any rate it's something for you to check.

 

 

[ZMB]

That sounds almost exactly what is happening, I did set the preload on the stronger side rather than the lighter side. So I have a few mechanical things working against me.
However I think I am also having something interfere with closed loop control that I have yet to identify.

1 hour ago, Puffwagon said:

Most of the time you will start losing control of the boost after 4000rpm which can be seen by the dropping duty requirements. Is this in line with what you're seeing? At any rate it's something for you to check.

I have not really been game enough to do a lot of testing due to how far it spikes but the way I would describe it is that you can really hear the wastegate shut at 4000rpm.
If I was in closed loop and requesting 10psi, doing a long 4th gear pull it would get a stable 10psi until 4000, then instantly it makes a very noticeable change in turbo sound, id say the gate closes somewhat and it winds up much harder and I get off the throttle as soon as I hear it. Perhaps that is what you are describing at that sweet spot and it just starts making a lot more boost.
I have tried to zero out auF0326 and auF0318 in case that was doing anything but this made no change.
I need to do more testing, but I dont believe it was doing this in open loop, only closed. It behaves just fine in open loop except for the constant WG Solenoid pulsing thing.

After I got back home from an open loop test, I noticed that the WG Solenoid was just constantly pulsing when I turned the car off and again when I tried to turn the car on about half an hour later. I put the previous tune back on that didnt force open loop and the pulsing went away. I was going to try and figure out what that was before I did more testing, but I was able to get a pretty stable boost curve on open loop without this giant 4krpm spike (at least I think I was).

I just need to iron out that pulsing thing and I can happily run it in open loop to do some more confirmed testing.

I dont get a heap of time to work on the car and dont have a lot of roads to test on that are suitable so things take a little while for me to test with any consistency.

[Puffwagon]

Just run a hose from the comp housing to the actuator and you'll eliminate any electrical control. At least you'll be able to see if there is a mechanical issue.

[hjtrbo]

If you're not already log the under and over boost flags. Would be interesting to see if the underboost flag is true when you have your issue in closed loop.

[ZMB]

I bypassed the boost control / WG solenoid and ran an air line from the compressor housing straight to the wastegate as puffwagon suggested and it behaves exactly the same.
It seems like its just overboosting because of the stock wastegate port size and I was overthinking it by the looks of things.

Now I'm on the lookout for a ported hot-side, considering doing it and a flapper mod myself but ill see what I can find first.

[Puffwagon]

Next step would be to loosen the preload and see where that gets you.

[BeerTurbo]

External wastegate fixes everything 

[Puffwagon]

1 hour ago, BeerTurbo said:

External wastegate fixes everything 

Ima buy my wife an external gate for xmas and if she complains ima show her this post

[ZMB]

I dont have a wife anymore so I think a 90 degree hood exit + external gate is the real answer to this problem

[BeerTurbo]

9 minutes ago, Puffwagon said:

Ima buy my wife an external gate for xmas and if she complains ima show her this post

My wife said i could turbo her rav4 at end of warranty... That must be soon.. maybe she needs a whirly boi n noise maker 

[Puffwagon]

Send it!