NefMoto

So I've been researching and I would like to bypass/delete my N249 in my B5 S4. To my understanding it will throw a code, what needs to be changed in the file to have no code for deleting N249? S4 wiki didn't yield any results. Thanks in advance.

What problem are you trying to solve by removing the N249?

i wanna delete too :)

What problem are you trying to solve by deleting the N249?

"Cluttered engine bay" most likely  ;)

Working turbos  :D

A++

No problem. A friend of mine did it and it seems to run fine. From what I've been reading most of the people that have done it dont have any problems but the people that warn against it are the once who haven't tried it. Most turbo cars Dv run off manifold pressure anyway, I don't see why it would cause harm to the S4.

Most of the people who've done it are ignorant to the detriment as they're the same people that haven't figured out how to take and interpret logs.

Can anyone tell me why to keep it there? Any actual evidence thats its actually useful? I've been searching a lot of forums and of all the people that have bypassed it 2 have reverted back. Also read NOTORIOUS VR mentioning to delete it many times.

Without the n249, when you let off the throttle there is a delay before the diverters can open due to a lack of vacuum in the manifold. The n249 prevents this by sending stored vacuum to the DV's to open them immediately. Without it there is a large pressure spike when the throttle plate closes. This air slams into the compressors and causes a drastic drop in turbine speed.

It is also impossible for the ECU to open the DVs to release pressure in case it's necessary. By deleting the N249 you are also deleting a failsafe.

Yeah, turbo life and re-spool speed... You might as well remove the dump valves altogether, clearly they are not needed for the car to run  ::)

Nothing like stalling the compressors with a wall of air travelling the wrong direction.

Should we also start a debate about installing the DV's in reverse?

Only if we can also talk about removing every other injector to save on gas.

I would also like to know. I have removed everything that the FIA aproved Rally Ibiza Cupra has on its 20vt or Cupra D model.
I am without n249 n112 and SAI  for 3 years now .

For guys like me that are racing in Circuit or sprint ,it should be useful to know

Hey guys, not everyone is running a standard setup.

Since when is this the place to push the idea we shouldnt mess with things?

This threads responses are for the most part pretty lame.  I don't run a n249, do you want to talk crap on me and or my setup and tell me my turbo is gonna fail?  ::)

No one is saying that your turbo is going to fail, but your allowing more stress on the turbo for no reason by deleting the N249.

Why delete it?

Because removing the N249 is akin to taking a hammer to your turbo's compressor wheel.
It's your turbo and you have a right to take a hammer to it, but when you go on a forum and start advocating it of course you are going to get negative replies.

Almost everyone over here runs no N249 and has no ill effects.

Thats what confused me lol. Every one that deleted it has no bad effects after running for extended periods of time, and the theory with the turbo compressor fighting resistance makes sence but it seems like there is no real world data to support it.

Oh come on now.  There is nothing wrong with running without the N249 and routing it to manifold vacuum instead.  This is just getting silly.

Speak for yourself. The moment you stop being sheep and start thinking for yourself is the moment you start getting anywhere in life.

Yes there is, the N249 is there for a reason - Audi went to using stiffer springs on the diverter valves at the same time as they implemented electronic dump valve control.

Running no N249 shortens turbo life, period. If you don't care about this, then go for it.
Your manifold vacuum is not sufficient to open the diverter with a stiff spring on transient load where the turbo spends the majority of it's life. Especially not the 710N.
This can be easily seen from logs and heavy pressure spikes with the N249 removed.

You can also remove the dump valve altogether. It's not like your turbo is going to fail over night, but it's life span will be affected.

I love the "everyone else is doing it, why shouldn't I?" approach. Even if there is only a CHANCE of a reduced turbo life, why chance it? There are cons to removing it, but none to keeping it.

Also, forgot to mention on lower loads keeping the dump valves open also reduces the amount of throttling that has to be done when no boost is requested, thus somewhat improving fuel consumption. This is especially true when using stiff spring diverters.

Maybe it's a diaphragm DV type issue then, I never seen any spikes in my logs with my piston style DV's to be honest.

Go on, post a log lifting off the throttle in the midrange.
I don't mean at 6000+ rpm where the intake vacuum is enough to open it instantly.

Does not matter diaphragm or piston, if your spring is too weak it will push them open coming on boost (especially the way most piston valves are mounted with the boost pushing on the piston).
N249 is effective in the normal operation area at lower loads, not in high rpm scenarios. Hell, you can see the boost climbing until the N249 kicks in when lifting off throttle with it fitted, without it, there is a massive spike.

here you go... there's a 200mbar increase and that is it... that isn't what I would call massive nor will it do any damage to the turbo(s) IMO.  But I guess if you can prove otherwise I'm all ears.

(https://lh6.googleusercontent.com/-UrN3DP5ZVxM/UYv5N3UbSVI/AAAAAAAAK34/7FYYzl1fv_0/s808/log.jpg)

That said, I'm not saying everyone should bypass the N249... I probably wouldn't do it again, since well meh why not keep it.  But I wouldn't go as far as saying you will wreck your turbos if you do remove/bypass it.

It's not a 0.2 bar spike, you are looking at it the wrong way.

Throttle plate is completely shut (3-13) deg and there is still 0.6-0.7 bar boost pressure before the throttle plate.
The turbos are experiencing compressor surge at this point. Look at the compressor map and see what happens to the surge line as flow is approaching 0.
Your logs illustrate exactly what I was saying. In fact your turbos are experiencing compressor surge for half a second each and every time you lift off the throttle in the lower revs, because your dump valves do not open at this point, might as well not be there at all.

I also never said "you are going to wreck your turbos".
I said - it will reduce their service life - what is so hard to understand?
The same way that removing the dump valves altogether is not going to wreck your turbos, it is also going to reduce their service life.

So - again, why would you remove the N249?

I think any decrease in turbo life is small on a tuned car.  There are plenty of OEM applications that do not use any kind of vac reservoir or electronic control of DV, and some have no DV at all.  My preference is very strong springs on big boost cars for driveability  Throttling the turbos on trailing throttle gives better response than any DV setup, but at a cost.

Rick

Would you mind posting a log from an S4 with the N249 connected as a comparison?

Whether the car is tuned or not is irrelevant.
The reason why they are there is to improve turbo life and increase fuel economy on lower load areas.
On high load, especially if revving the engine high, they do pretty much nothing, as at high revs the vacuum generated by the engine is more than sufficient to pull a dump valve with even the strongest spring wide open.

A part throttle example with N249 attached. Note no spike and boost dropping much quicker, no surge occurring.
Not an S4, but it looks the same on the S4 as well ... and my RS4.
This example is especially nice because it is a BAM engine, so stiff dump valve from factory.

My point is simply that there is a difference, the turbo is exposed to more surge, it is seen in the log.
How much running a turbo with no dump valve at all affects turbo life is a different discussion altogether, but you can not say that "there is not any difference", clearly there is.

Many many modern cars dont have fancy valves/ecu controlling the dump valve.  Look at the early AGU/ARZ motors with no N249....Ive never known a turbo to fail/lifespan be shortened by running no valve.

From what ive read/understood, people often get part throttle 'dumping off' where the N249 is opening the valve on part throttle causing a jerky drive.

When the throttle plate is closed, the DV is instantly in vacuum, (you dont see a boost gauge taking half a second to stop reading boost pressure to vacuum pressure)  The boost helps keep the valve closed, vacuum opens the valve.

Its like all the other crap that comes attached to the later 1.8T engines...SAI, EVAP, N249, charcoal canisters on all models.  fact is, the motor runs perfectly well without any of them in situ,

The boost gauge is taking its reading from after the throttle body so you can't rely on that.

Rick

AGU has softer spring on stock dump valve. Your reasoning is also ridiculous - as it was said before, the lifespan IS shortened by running no dump valve (which you are essentially doing at part throttle with a stiff spring), it is universally accepted that violent stalling of the compressor causes high load to be applied to the shaft and the bearings of the turbocharger. Have you disassembled even one turbo? Do you have any idea what goes on during compressor stall?
Wrong, this part throttle jerkiness is caused by bad tunes. On a properly tuned car there is no issues whatsoever with things interfering when they should not. The N249 never ever opens unless there is a negative pressure gradient (only exception is huge overboost). On a good tune there will be never a negative pressure gradient during constant throttle application.
Incorrect, on lower engine speeds the vacuum generated by the engine is not sufficient to open valves with stiffer springs, such as the 710N. Especially since the load applied from the side of the diaphragm is actually helping keep it closed.
The only thing that I agree removing with is SAI - this is only there for emissions and warming up the catalytic converters quicker, but as a side effect bore washes the engine during every cold start.
By removing EVAP you are turning your car into a potential fireball during a crash, as your petrol tank is full of very explosive fumes all the time.

But hey, clearly what you read on forums is all true, and Bosch has no idea of what they are doing, isn't it?
Your only arguments so far have been "everyone else does it", "there are cars without it". By making such remarks you just make it look like you understand absolutely nothing about forced induction engines and turbochargers.

The only thing up for debate is just how much turbo lifespan is reduced by running no dump valve - many opinions on this one.
But:
a) N249 does not interfere with anything, unless your tune is utter crap
b) Removing the N249 causes pressure spikes and increased amounts of compressor stall.
c) Compressor stall (also called surge) has a detrimental effect on the bearings.

These are the hard facts about it. Fact is also that the Audi Rally team ran no dump valve of any sort on the S1 - thus the characteristic sound, but they could also afford to fit a new turbo for every race.
Any kind of MAF setup with a closed-circuit PCV will also not take kindly to this, as the air will travel backwards inside the intake during compressor stall and oily mist will land all over the air filter and MAF causing incorrect operation of the MAF.

The arguments for deleting the valve in this thread are ridiculous.

There's no debating that it effectively prevents an undesirable condition and the valve only costs ~$80.

IMO it's a desirable feature and I don't see how one can argue against it just because it isn't offered in every car.

SAI and EVAP are emissions devices, I don't see the correlation.

I have seen logs showing relatively massive "boost spikes" on throttle closing and I believe Britishturbo had posted one on this site.

No one is saying that your turbos will pop instantly after removing the valve, but why subject them to unnecessary abuse?

Again, the question is WHY delete it?

If your only argument for it is the shorten life span of turbo, AND the measurement of that decrease of life span is negligible, then the the reasons to get rid of it out weight the reasons to keep it.

 

What are the reasons to get rid of it?

Negligible according to what?

When I consider risk versus reward (no reward I can think of), it's a no brainer.

Potential shortened turbo life is a good enough argument for me.

Did you read what I wrote about the MAF fouling?
Bosch also says it improves fuel efficiency, which makes sense, as pumping losses can be reduced by keeping the valves open in some situations when no boost pressure is desired, allowing to hold the throttle wider open as opposed to choking the engine with it.

As to whether the effect on the turbos is negligible or not, well that's the only thing that can be debated.
But please list a single reason to remove it? It does not weigh anything and takes almost no room. They also very very rarely fail.

I agree with prj.
BUT remember we are on a forum where a majority of forum members don't know that much about computers, physics nor tuning in general but still experiment with removal of torque monitorin, knocksensor sensitivity, ALS, NLS and tuning of plain old fueling/ignition maps. Hey, most don't even know much about computers and they compare binaries guessing that they've found the right map or even single byte values without checking ASM to verify correctness.
Given this I think removal of N249 is a VERY negligible shortening of life of their vehicles compared to most other things members do. But still, why remove a modern motronic feature that when tuned correctly works well?

What I'm trying to say is that we instead of arguing about the pretty harmless removal of N249 (when put into perspective), we should put our energy on working with Me7sum, Winlog plugins, Tunerpro plugins or what ever else we are capable of. :-)

edit: not me7checker, me7sum

yes ploz. Need help finishing ME7Sum :/

We left reason on page 1

I meant ME7Sum

(http://imgs.xkcd.com/comics/duty_calls.png)

Good night :P

 ;D ;D ;D ;D ;D

So it is settled then. Although N249 valve has use deleting it doesn't cause any mesurable decrease is turbo life. My friend has had his bypassed for 60,000+ miles and his K03s are as strong as ever. I Deleted mine and like most people noticed smooth part throttle. I realize this could be because the Valve is bad but I see no reason to drop $80 on replacing it when there have been to direct bad effects from deleting it in real world use and abuse. The only reason I can think of is the CEL. So now were back at the orignal point, How can that be deleting out of the tune so I can pull out the valve completely instead of having it plugged in.

I'm beginning to think you're trolling with comments like this. NOWHERE IN THIS THREAD IS THAT SAID.

Im starting to think you're not reading what I wrote. There are some very good points made in this thread. BUT in REAL WORLD USE I had yet to encounter a SINGLE person that is had turbo problems due to this valve being deleted. Spiking your stock turbos to 15PSI from stock boost levels probably puts 100 times more strain on the turbos then this valve being bypasses would. So not to the topic at hand. How do you code it out is there is any way to code it out.

Someone wake prj back up :D

No. Everybody did. Unless somewhere you expressed what problem you are trying to solve by deleting it, and nobody saw it.


I do not think you (or anybody else who has bypassed the 249) has the ability and/or knowledge of determining this in any conclusive way.


Nope. Surge can happen at any time. Stalling the compressor can happen at any time.

In contrast, 15 PSI is nowhere near the overspin line, just about everywhere.


Demanding answers doesn't generally work well here.

Insulting everybody, then demanding answers is even less effective.

If everybody who has bypassed them is so smart, you'd think they'd have

1) publicly explained why coding it out is advantageous
2) publicly explained why coding it out doesn't have any drawbacks
3) publicly explained how to code it out

Lol I don't understand why everyone is so edgy over this, No one is demanding answers. If you don't want to help thats fine, the thread will die and go to waste like many others do nothing unusual. Ive said it before I'll say it again. I bypassed mine and my car is smother as a direct result of it. I realized the valve could be bad but I don't see any threads expressing any damage that has been caused by deleting the valve just theorys as to why it could be bad. I see no reason to buy a new valve and replace it as my car is doing great without it. Only problem is I have to keep it plugged in so I do not get a CEL, which isn't a huge problem but I'd rather code it out and just take it out all together. Which is the reason I started the thread. No one is demanding any answers just asking is anyone knows any info on how to code it out, thats all.

Shoot me a pm my man. I will help you out.

Why not post it publicly?

I really don't get the pm obsession.

CWDLDUV. Codeword fur diagnose schubumluftventil?

Not in ME7.1

Because I know you asshats will keep going with how retarded it is. Him deleting n249 isn't going to affect how anyone else's car runs. Kid asked a question, if you have the information help him out.You guys need to stop turning this into audizine with all the enormous egos.

I just installed an N249 into an Opel Astra Turbo  ;D

How would you suggest somebody try to explain the topic to somebody who simply refuses to listen?

Of course people are going to get emotional.

Blaming the messenger doesn't solve anything, especially if all the messenger (ultimately) wants is for the person who is asking a question to

1) fully understand the question
2) understand the answer and its full context

Just demanding answers w/o showing any willingness to understand the context doesn't help anybody.  It just perpetuates bad information.

Just randomly giving out answers and nothing else IS EVEN WORSE, because not only does it perpetuate bad information, it loans credibility to bad information.

Finally, do you really think I would rollback an edit to the s4wiki that added a section on deleting the n249?

I am really disappointed with this thread, or rather many people in this thread.

Thank you imolasb5 for sharing , I will pm you too.
I dont want to be rude but why you all attacked him.We are not here to judge what he want to do or not ,just show him what to do if we know ,correct ?

As I said in page 2 or somewhere and no one read  it ,Well known homologated VAG teams (including Seat Sport) delete SAI n112 n249 etc. Its is even in the manual in the seat-sport.com homepage.
Some of us (me included) are racing in tracks or sprints.

I read a lot of nonsense here about n249 and I dont want to discuss it ,just stop scaring people :).
Sorry if I offend someone , I dont usually do posts like this but I felt that this was unfair

The problem is that as emotions heat up, people confuse trying to educate as judgement. And as I said in my previous post "just answering the question" isn't a good idea if the person asking the question keeps ignoring what others are saying, and insisting that "they just answer the question". Of course the results aren't going to be pretty!


Speaking personally, that isn't good enough. I know nobody wants to hear this, but I do not accept arguments from authority. I accept arguments that come from logic and a good  rationale.


IMO what happened in this thread is not suprising to me.

Same old tension between "answer the question, don't tell me more" and "but you should know more".

Same old tension between "just do this, don't ask why, i know race teams that do this" and "please explain why".

Nyet you have a point ,yes. I too try to understand what I do and why before I do it .

The problem is this thread will make me think twice before I ask something here again :)

Yeah I mean the champion motorsports world challenge team and the stasis WCTC team did the same, but wtf did we know?  Just multi million dollar race teams with factory audi and quattro gmbh support that won races, won series, won manufacture titles...

What i am saying is that you cant lambast people with why you think they shouldnt do something.  They are asking for help, you can either help or not help.  I didnt see him asking for advice on if he should, that decision was already made.  How do you know he isnt running after market valves?  How do you know he isnt running a race car that he plans to replace the turbo on every race (btw, that was a false statement about the Audi I5 cars anyway) how do you know that the opinion you are trying to force down his throat is even applicable?

I could say some more about how i feel about a few of you in particular right now.  but i will leave out names, you sure do talk a big game and like to down people with your so called experience a lot.  i deleted the n249 valve in 2005 when i built the worlds fastest/quickest ko4 based turbo 2.7t powered car.  those turbos didnt fail, that car ran fine, so my real world results trump your internet speculative bullshit attitude anyday.  I seriously think you are mostly all talk, you claim to be superior but i personally never heard of you before this site, i have never seen a fast car that was tuned by you so seriously lose the king of tuning attitude.

If you dont have anything nice to say, dont say anything at all.

Ok fine, how about this.  the DV or BOV works off vacuum, without the n249 the vacuum still pulls the valve open.  if your car cant create enough vacuum then you have an issue with your engine or your springs in your valves are not of a proper rate.

From my perspective (speaking as a novice who is still learning), I would like to know the rationale behind deleting the n249

it really is that simple.

I understand why it is there, but I do not understand why it should be removed.

"well x person runs it" isn't good enough for me.

I will do my best to try to defuse things in the future, but no guarantees. As I said, IMO this sort of tension is inevitable with the personalities (self-selecting for "tuners") involved.

Because it isnt needed, it is an added system that works well on the factory setup.  When we start to modify these cars even to moderate levels we are changing parts that may affect how it works anyway so why not remove variables and extra components that are not needed?  There is no difficulty in getting the system to work just fine without it and now you have less lines, valves and components to worry about.

This is akin to saying that people shouldnt run more boost, differnet turbos, different injectors because thats not what audi intended.

nye, you know i literally love you, but you set this thread into this direction.  look at the first posts on the first page.

same as when someone asks about running mafless.

also, incase i need to clarify, the un named person i speak of above is not you, but if it at all felt like i was talking about you then...

Nyet summed my views up very well. If I thought the OP was well informed, I would have answered the question. Having done so in the past, I hate just giving a solution without making sure the consequences (potential or likely) are known and understood.


Noone disputes the car WILL open the DV without the N249, just that it won't be instantaneous at lower RPM's. While I agree detriment in the short term is unlikely, it isn't ideal. The cons outweigh the pros in this instance, and I can't in good conscience advise on how to do it without first satisfying my conscience.

Hmm. Sorta. I think a more appropriate analogy would be SAI, rear O2 or EGT delete...

And i understand the rationale behind all of them... the EGT delete being the only potentially hazardous mod.

From what I understand about the n249, I still can't understand how removing it would be safe *even though i agree with the concept of keeping things simple* :(

sorry, maybe I'm just dense.

Perhaps you can just say "well removing the EGT is actually riskier"... and that's that.

Sure. I will concede that. BUT

It drives me insane, because both questions generally come from people who not only don't know the ramifications, *they actively refuse to even consider them* then get insulted when somebody tries to suggest maybe they should learn more.

Granted, the response is generally accusatory when it comes from me. But I am prejudiced, because i assume that whoever is asking is clueless. Why? Because 99% of the time, it is true. They heard it from somebody who said somebody they know heard somebody does it and it is awesome! Is it any wonder I am demonstrably frustrated?

I will try to be more level headed in the future, but at some point, that would require somebody to prove me wrong. And IMO it won't happen. Those people who already KNOW the ramifications have probably figured out how to do it on their own and wouldn't ask here anyway.

Meh. I will try.

And the rest of your post... i love you to bro.

Thanks Nyet.

I will speak from expirience only ,not what I read in forums or based on opinions.
Keep in mind I maybe new in maptuning ,but owning a small garage I modify VAG cars -petrols only- the past 7 years.
Racing from 2008 and this October I will race my first Rally sprint race :)

Removing N249 in my Seat Leon FR and Ibiza FR (I use Ibiza for trackday use) , I saw an immediate
throttle response when lifting my foot from the gas pedal.I can more easily "play" with my throttle when in/out
of a corner.There is no more boost loss or surging (obviously) when WOT under certain conditions.

I should also mention that removing n249 will not have any effect on turbo ,please if someone can point me out why Turbo should be stressed more..Also ,about DV Spring that is too hard and without N249 ,could not be lifted..Thats also wrong,
I had a Blow off valve in Leon and it lifts even more the spring.You can also hear it in stock DV.It makes no sense that n249 can lift the spring more ,since it takes vacuum also from the same place.

P.S. MY English suck if you can read and understand my points ,congruts and thank you for your parience  ;D

TigersClaw:

Thank you for you response, and for trying to calm things down :)

I don't fully understand what you are saying but I think i get the gist of it and i'm trying to digest it now.

Still tons of crap said and not a single scientific explanation posted by the "delete everything" posters.
Just taking lots of things out of context. For the final time, the turbos are not going to explode even if you remove dump valves altogether.

They will just experience more surge. Just as they will experience more surge with removal of N249.
Lending examples from motorsport teams is completely irrelevant, as on a motorsport car the N249 is useless, as that car is driven to very high RPM's all the time where the generated vacuum will instantly open the dump valves anyway. Not to mention motorsport teams really don't give a damn about long term turbo life.
Part throttle issues only exist on cars with messed up tunes - even then, if you feel it intervenes too much for some reason you can easily tune the negative pressure gradient required for the boost to drop.

The N249 is a device that is there to prevent stalling the compressor at low transient loads in a day to day car. It can also function as a safety device in case of wastegate stuck shut.
This:
* Eliminates compressor stall on the turbo at low loads thus extending it's service life
* Prevents air from moving backwards through the intake tract and oil mist building on the MAF.
* Somewhat improves fuel economy by reducing pumping losses.
* Can save you from a grenading turbo and engine damage in case the wastegate actuator becomes stuck for some reason.

On any motorsport car this device is useless because:
* The motorsport car is not driven at low transient loads.
* Because of how little time it spends at low transient loads this is not going to have any measurable effect on the turbo life
* Fuel consumption is completely irrelevant.
* Most likely you are running PCV that is vented to atmosphere or has a catch tank, as without it you will have very high oil consumption, so there is not going to be any oil vapors in the intake air.
* Turbos are not mounted on motor sport cars for 10+ years, so there is almost no chance that the actuator is going to be stuck.

Removal of it makes nothing better, besides saving 300 grams of weight, if that, assuming the torque management of the ME7 ECU is tuned correctly.

To remove the DTC's associated with the N249 valve you will need to:
* Find the relevant bits in ESKONF (on the 1.8T this is the 2nd to last bits in the fourth of the seven bytes) and set them to 11 - that will kill end stage diagnosis and the open circuit code.
* To remove the plausibility diagnosis you can for example FF DLDUVES or TMDLDUV - this worked fine for me on 1.8T

How exactly does it do these :
* Eliminates compressor stall on the turbo at low loads thus extending it's service life ??
* Prevents air from moving backwards through the intake tract and oil mist building on the MAF. ????  ???
* Somewhat improves fuel economy by reducing pumping losses.

I fail to see it.Really  ???. It is a switch for the DV .It is there only to have a smooth feeling when throttle lift off and
as a failsafe.

I am not being a smartass I am trying to understand how did you come to these conlusions :)

Also really thank you for pointing out how to remove it PRJ  :)

I think you need to read the entire thread and not read selectively.
We posted logs, without N249 and with N249 where it is clearly seen that the boost spikes up on throttle liftoff with the throttle shut on lower RPM's with the device removed.
During that spike the turbos are experiencing compressor stall. Have a look at the real world logs. Have a read of some of the factory documentation about the N249.

And besides, you have to argue not with me, but with Bosch and the basics of turbocharger operation about this.
Anyone who understands a compressor map can see how 0.7-1 bar of boost at 0 airflow is going to cause surge on any compressor.

who are these delete everything posters you refer to?

why are first hand real world experiences with the deletion of the n249 and the subsequent improvement in drivability from their perspective "crap" to you?

How scientific do you want to get?  Is in really needed to get scientific in regards to understanding how boost will hold it shut and vacuum will open it?  Do you not like to control your vehicles behavior?  with out the n249 the DVs or BOV will be controlled by your right foot and your right foot only.  My brain is better than any motronic ecu, ever.

You clearly have not even read the FR part dealing with this. The N249 is controlled ONLY by your right foot already. The only exception is when the compressor exceeds the pre-set surge limit. It's a device that compensates for insufficient engine vacuum in lower transients. Opens only when you are lifting off throttle quite sharply.
This is why VAG went electronic re-circ on everything, to remove clutter and retain the ability to open at will.

And you clearly think you are the MAN.

 ::)

You are saying in one post that with the n249 in place you don't control it directly and then in another trying to say you do.  Which is it?  I can read just fine, I am perfectly aware of what the FR says as well as how it works with and without ecu/back res. control.

A perfect valve is achieveable that doesn't need any help functioning perfectly.  Get your spring rate right and the valve holds shut where it needs to with the aid of boost and opens as soon as it needs to with less or no boost.  I would rather tune my hardware to be as spot on as possible over tuning around poorly spec'ed hardware any day.

Wow.

Sorry, but I personally don't like to perpetuate what is nonsense IMO. This becomes the flavor of the month every so often and everyone wants to do it because everyone is doing it.

I don't know why anyone is getting so emotional here. There's no obligation here and I have the right to share my concern. I am more obligated to impart the caution that I've deemed is warranted.

Anyway, the only thing needed is ESKONF in ME7.1. Personally, I would prevent B_lsua from setting via GWPLDUR, GWPLDU, SVDLDUVS, and HSSLDSUA.

This is also checked in DWGASLV which appears to basically be a dead function and the DTC isn't registered nor documented.

Yeah, ME7.1 does not have plausibility diagnosis at all, so ESKONF is all that's needed.
ME7.5 has some logic actually checking the operation of it though.

No emotions here, but if PRJ wants to play bully I will out do him 10 times over.

Modifications to our cars given systems are hardly a flavor of the month.  It's what we all do and the shit attitudes in this very thread go against everything this forums is supposed to be about.

Guys, can we please stop with the sniping. Just stick to technical info. I admit I am as guilty as the next guy but I will try to restrain myself.

It happens man we all do it.

There you go prj. Bam here's the facts and if you still want to do it, this is how you go about it. Op is happy and you gave back to the community. Now nyet can get pissed and tell the next guy look for this thread :) as we know it will come up 100 more times lol.

Okay, Let me clear things up. nyet, OFCOUSE I appreciate you and other telling me what could pontelitaly be the downsides of removing the N249 Valve. I Think I fully understand about the delay it will cause to open the DV after getting off the throttle before vacuum is created and that will cause a compression surge which COULD shorten the turbo life. Im not ignorant I undersand that theory. From me research and many other members like TCSTigersClaw No one has yet to post about any serious problems they have encountered by deleting it. In fact, most people say part throttle is smoother also methtioned my countless others including. You keep asking me for a reason for me to remove it and I have stated it at least twice, here it is again. After bypassing the valve, My car feels much smoother. I realize My valve could be bad but I see no reason to drop money on a new valve if my car is doing much better without it. I have it just plugged into the harness so i don't get a CEL, I'd like it remove it completely and just code it out. I can not be any more clear than that.

ESKONF is your answer. Other solutions are just error class hacks which just hide the code. To properly remove it you need to find the bit and configure it as a non-installed option.

I can give you the address, but someone needs to chime in with the bit pair configurations.

Snow trooperI don't see how prj is doing anything but contributing facts including logs with and without the n249.  It seems you are have a personal grudge against him in every post in this specific thread. Prj even contributed insight on deleting the valve.  If you have so much experience with the benefits and deleting the valve where is your contribution in logs and in how this valve can be coded out besides "oh bro I have one of the fastest k04 s4s"?  I see nothing wrong with the discussion of how the valve works and why its there.  Panties are in a bunch on both sides of the table the way I see it.  On the other hand hearing the pros/cons and the actual function of the valve prooved to be very informative 

FWIW-- I've been following this thread and, between all the bickering, I've gained a pretty complete understanding of how this system works.  Will definetely be helpful in the future, so thank you!

Your right, maybe I should have offered to pay him earlier in the thread like he wants and he would have been helpful before jumping in to down people for wanting to test things on their cars.

Also I didn't say bro.  Read my first post in this thread, I hardly came out swinging.

i will add in on this. i read further in  the beginning that n249 uses stored vaccum since the manifold will not open dv's but if you are coding out the 249 you have probably done enough research to have t'd these off from a constant vac source as the engine does have one. it shouldn't be a battle of idiocy for doing it but the facts given for one to decide and rep the pros or sorrow the cons... mine is gone and i can tell you I have run both ways & no difference other than less bypassible shit under my hood!

Maybe I'm confused, but I don't see how a turbo motor could have a constant vacum source (not stored in reserve somewhere)?

PRJ: I thought the bits comprising the 4th byte were LSHHK EFLA LDR TEV

Isn't the 3rd bit LDR-Taktventil?

Or is that incorrect? Thanks!

NVM, I had my acronyms messed up. Taktventil=pulse valve.

LDR=?

I guess LDR would be N75.

LadeDruckRegular

boost pressure regulator...

Yeah, it's the wrong bit that I quoted.
Would have to look into some files I have, I have coded this out plenty of times, just don't remember what the exact bit is.

1st bit, 7th byte, ULT would be my guess.

On a 1.8T I tell everyone to remove the N249 and set the DV to run via what the throttle valve/ manifold MAP is doing.  Much better reaction, response better boost recovery between gear changes, less/no turbo flutter or stall.  Never had any issues nor will is ever have any issue.  So its all Pros with N249 removal and no Cons here with me and my customers.

It sounds good but would it be possible to see logs before and after removal? (Boost vs RPM)