NefMoto

Noob Zone => Noob Questions => Topic started by: zCruuz on December 25, 2021, 07:15:48 AM



Title: fixed WGDC low boost K04
Post by: zCruuz on December 25, 2021, 07:15:48 AM
Hi everyone!
According to http://nefariousmotorsports.com/forum/index.php?topic=12352.0title=
I did some logs yesterday to adjust my PID for my spring pressure and make it pre-control.

I switched CWMDAPP=8 and adjusted KFLDRAPP accordingly.
Turbo is a K04-023 with billet compressor, for this i think the boost is too low.
N75 is working, i tested it on the workbench, Vacuumline are all new and pressure tested, the boost pipes also.

Can this be a software issue? Hardware wise everything has already been replaced.
Car is a AGU swapped to ME7 with everything deleted (VVT and N249 will get in their as i find time for it).
The dumb i modify is the AUM one.

80 and 95% logs are bad, i had a N75 in my trunk and tried this for the runs. It ended up being fault and the car only made spring pressure.


Title: Re: fixed WGDC low boost K04
Post by: fknbrkn on December 25, 2021, 08:08:58 AM
Sw problem? Did you log ldtvm? If yes then why are you asking?
Run it wo wg vac line to check max boost on it
5min deal


Title: Re: fixed WGDC low boost K04
Post by: Blazius on December 25, 2021, 08:25:33 AM
What the hell is going on here, boost going up at 6k? Run it at 0 wgdc see what it does and 95 wgdc and if it doesnt do what it needs to then youve got a problem.


Title: Re: fixed WGDC low boost K04
Post by: zCruuz on December 26, 2021, 04:42:39 AM
Sw problem? Did you log ldtvm?

yes, wgdc did what it should. i assume it be hardware too. I'm still learning a lot sw wise, since i'm no native english speaker my "questions" may be a bit dumb in their formulation.



What the hell is going on here, boost going up at 6k? Run it at 0 wgdc see what it does and 95 wgdc and if it doesnt do what it needs to then youve got a problem.

I found the issue i guess. Had slightly loose bolts from exhaust manifold to turbo which ripped the gasket. I hate this "upgrade" manifold since i first installed it.


Run it wo wg vac line to check max boost on it

Is N75 system really this dumb to only allow spring pressure? I overthought it then, assuming it 0% boost opens the WG and  95% boost goes into intake which causes venturi on wastegate to produce spring pressure  + vacuum to get higher boost levels.


Title: Re: fixed WGDC low boost K04
Post by: nyet on December 26, 2021, 11:45:10 AM
wg opens with pressure > spring, not vac.


Title: Re: fixed WGDC low boost K04
Post by: zCruuz on December 28, 2021, 03:24:15 AM
wg opens with pressure > spring, not vac.
So if i get this right, spring pressure = max boost
My wrong understanding was
-0% DC   => Boost opens WG
-95% DC => intake port in N75 open, boost gets sucked in intake and creates vacuum at WG port (like venturi in carburetor) 



Should i switch to BAM file, since i still drive K03 file on K04 turbo, to get all the maps relevant for the turbo to a closer match?


Title: Re: fixed WGDC low boost K04
Post by: aef on December 28, 2021, 04:31:28 AM
attach logs of your fixed wgdc runs



Title: Re: fixed WGDC low boost K04
Post by: nyet on December 28, 2021, 01:12:50 PM
So if i get this right, spring pressure = max boost

No. Spring pressure is min controllable boost

at 0% WGDC, the wg sees manifold pressure, which means it cannot open until manifold pressure reaches spring pressure
at 95% WGDC, the wg sees ambient pressure, which means the WG stays closed regardless of manifold pressure


Title: Re: Re: fixed WGDC low boost K04
Post by: zCruuz on December 29, 2021, 02:05:34 AM


No. Spring pressure is min controllable boost

at 0% WGDC, the wg sees manifold pressure, which means it cannot open until manifold pressure reaches spring pressure
at 95% WGDC, the wg sees ambient pressure, which means the WG stays closed regardless of manifold pressure

Now im really confused. My mechanical experience and understanding of n75 was
-0%  boost goes to wg, intake Port closed
-95% all three ports open

I also read sometimes that people had n75 behaving like this, where 95% opens intake and closes boost port.

This would mean I own masses of broken solenoids and would have to buy Till I get a working one.



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Title: Re: fixed WGDC low boost K04
Post by: zCruuz on December 29, 2021, 07:35:46 AM
attach logs of your fixed wgdc runs



since i'm not sure if N75 is broken or wastegate was overtight i adjusted WG new.
And logged today with fixed 95% WGDC

-everthing connected
-WG removed from N75, N75 port sealed
-WG line connected to intake hose, pressure line blocked

i'll attach the logs. I dont understand why torque spikes so high over requested right before boost dropping.


Title: Re: Re: fixed WGDC low boost K04
Post by: nyet on December 29, 2021, 10:37:57 AM
I also read sometimes that people had n75 behaving like this, where 95% opens intake and closes boost port.

Why would you trust a random person on the internet?

https://s4wiki.com/wiki/Wastegate_bypass_regulator_valve

You don't have to trust the wording. Look at the diagram.


Title: Re: fixed WGDC low boost K04
Post by: nyet on December 29, 2021, 10:42:10 AM
since i'm not sure if N75 is broken or wastegate was overtight i adjusted WG new.
And logged today with fixed 95% WGDC

-everthing connected
-WG removed from N75, N75 port sealed
-WG line connected to intake hose, pressure line blocked

i'll attach the logs. I dont understand why torque spikes so high over requested right before boost dropping.

You are beyond confused, I don't know where to start.

If you are completely overriding the PID, why would you expect requested to be relevant?

secondly, why are you only making 11PSI on a totally shut wastegate?

Before you do any further work, i'd back up a step and thoroughly rethink whatever it is you are doing.

I'd say either your wg is leaking, your turbos are shot, you have an intake leak etc. etc.

With the wg entirely disconnected, your tune has zero relevance.


Title: Re: Re: fixed WGDC low boost K04
Post by: zCruuz on December 29, 2021, 02:09:21 PM
Why would you trust a random person on the internet?

https://s4wiki.com/wiki/Wastegate_bypass_regulator_valve

You don't have to trust the wording. Look at the diagram.
got this, my only mistake was the "venturi-principle".


If you are completely overriding the PID, why would you expect requested to be relevant?

Requested torque was the first that i noticed when ecuxplot didnt find a pull. After that i had a look and saw, when boost and torque peak, throttle closes to 25%. Which i guess shouldn't happen, can wrong VVT delete cause this? May i upload my file and def and someone could be so kind take a look if i messed something up to cause this? 


secondly, why are you only making 11PSI on a totally shut wastegate?

I'll adjust the wastegate preload again, was experimenting with it, dont want it to be overthight.

Before you do any further work, i'd back up a step and thoroughly rethink whatever it is you are doing.
i didn't even tune. Had a way too tight wg which caused a lot headache and now i dont want to dismount dp to adjust preload. But i think i'll have to.

I'd say either your wg is leaking, your turbos are shot, you have an intake leak etc. etc.

I'll check for that. May it be low wg preload.



If relevant after the logs i checked for dtc and got two
-first was boost too high
-maf reading exceed limit

but probably they are caused by closed throttle at boost and high rpm.


Title: Re: Re: fixed WGDC low boost K04
Post by: nyet on December 29, 2021, 02:18:54 PM
throttle closes to 25%.

thats what happens when you exceed requested by too much. Search for throttle cut in the s4 wiki


Title: Re: fixed WGDC low boost K04
Post by: zCruuz on December 29, 2021, 02:38:54 PM
thats what happens when you exceed requested by too much. Search for throttle cut in the s4 wiki
So i can get throttle cut caused by deviation although i drove fixed WGDC? I thought LDR gets deactivated when KFLDRAPP is used?


Title: Re: fixed WGDC low boost K04
Post by: nyet on December 29, 2021, 02:40:40 PM
So i can get throttle cut caused by deviation although i drove fixed WGDC? I thought LDR gets deactivated when KFLDRAPP is used?


Good question, i'd have to look at the FR


Title: Re: fixed WGDC low boost K04
Post by: zCruuz on December 29, 2021, 03:09:31 PM
Good question, i'd have to look at the FR
I did a quick search in FR for CWMDAPP when you mentioned throttle cut. The only chapters that i found related are

-FUEDK 21.90 : fixed value for CWMDAPP deactivates torque and links throttle with pedal
-LDRUE 30.30/LDTVMA 21.10 : whole LDR can get deactived through CWMDAPP

I attached the file i flashed, maybe the error is in there.


Title: Re: fixed WGDC low boost K04
Post by: Blazius on December 30, 2021, 06:35:30 PM
So i can get throttle cut caused by deviation although i drove fixed WGDC? I thought LDR gets deactivated when KFLDRAPP is used?


CWMDAPP( 8 ) does indeed disable whole PID which you should use for a fixed wgdc run , but however it doesnt disable all the other components, so you can have issues with requested boost, underboost and overboost and you get throttle cut,  even if you are only doing a test. Its pretty funky.


Title: Re: fixed WGDC low boost K04
Post by: zCruuz on March 20, 2022, 08:48:45 AM
problem is found.

N75 was bad, only allowed about 1 bar boost.