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prj
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« Reply #75 on: May 10, 2013, 11:54:40 AM »
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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
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« Last Edit: May 10, 2013, 12:03:34 PM by prj »
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TCSTigersClaw
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« Reply #76 on: May 10, 2013, 12:02:50 PM »
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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  |
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VAG cars newbie tuner |
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TCSTigersClaw
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« Reply #77 on: May 10, 2013, 12:04:00 PM »
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Also really thank you for pointing out how to remove it PRJ |
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VAG cars newbie tuner |
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prj
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« Reply #78 on: May 10, 2013, 12:06:07 PM »
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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 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. |
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« Last Edit: May 10, 2013, 12:07:45 PM by prj »
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Snow Trooper
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« Reply #79 on: May 10, 2013, 12:06:36 PM »
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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.
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cartoons?
6A 61 72 65 64 40 76 6C 6D 73 70 65 63
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prj
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« Reply #80 on: May 10, 2013, 12:12:52 PM »
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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. |
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« Last Edit: May 10, 2013, 12:16:18 PM by prj »
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Snow Trooper
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« Reply #81 on: May 10, 2013, 01:12:06 PM »
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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. |
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« Last Edit: May 11, 2013, 03:06:22 PM by Snow Trooper »
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cartoons?
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phila_dot
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« Reply #82 on: May 10, 2013, 02:37:13 PM »
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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.
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prj
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« Reply #83 on: May 10, 2013, 02:43:17 PM »
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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.
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Snow Trooper
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« Reply #84 on: May 10, 2013, 03:52:05 PM »
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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.
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cartoons?
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nyet
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« Reply #85 on: May 10, 2013, 03:54:41 PM »
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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.
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ME7.1 tuning guideECUx PlotME7Sum checksumTrim heatmap toolPlease do not ask me for tunes. I'm here to help people make their own. Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
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imolasb5
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Karma: +5/-1
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Posts: 38
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« Reply #86 on: May 10, 2013, 05:16:32 PM »
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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. |
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karrann
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« Reply #87 on: May 10, 2013, 08:37:25 PM »
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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.
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ddillenger
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« Reply #88 on: May 10, 2013, 08:41:33 PM »
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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.
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Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience!
Email/Google chat:
DDillenger84(at)gmail(dot)com
Email>PM
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savages4
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« Reply #89 on: May 11, 2013, 01:51:43 AM »
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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
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