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.