# How to N249 Delete - easy way



## Grahamstt (Jul 22, 2008)

This was done in such a way that if you have problems it can be reverted back to std.
The aim is to maybe improve throttle on/off jerkyness :? and get rid of this mess of vacuum pipework;-








The N249 valve is the grey block with the connector - unplug this to give more room
The two pipes we're interested in are the ones with the red cable ties attached;-








We want to join these two pipes as one is a vacuum pipe and the other goes to the DV so remove the clips and then the pipes from the N249 valve.
Remove this pipe together with the T piece as we will use it later








Remove the second vacuum pipe then the last pipe (Y piece) from the N249;-








Now undo the 10mm bolt and remove the resonator/pulse absorption box together with unwanted pipework;-








You should have something like this - note the pipe that I found with a split in it that broke during removal;-








Now we need the T piece with the pipe that was removed earlier. This is going to be our adaptor as the two pipes are different bores, the pipe is left on so we can seal off the unwanted side of the T so use a suitable bolt and utilize the original clip to make a good seal;-








Do the same with the second vacuum pipe.
Connect the DV pipe to our new adaptor and then the first vacuum pipe. Remember to use the clips - although these are vacuum pipes, under boost these will pressurise
Re-connect the N249 valve to the electrical connector, this way no diagnostic codes will be set, cable tie it to the metal bracket then tidy up the remaining pipework in the same way;-








This may be a bit of a Heath Robinson end result but it is fully reversible if you have problems. If you want a neater job then after testing that it's ok you can trace the vacuum pipes back to the manifold and blank off the unused second pipe and then use an adapter to join the two pipes, rather than the T piece that I have used.
If you want to remove the N249 valve completely then it has been posted elsewhere on this forum. [smiley=book2.gif] 
Otherwise we have less pipework to give us boost leaks as well as better pedal feel - and it costs nothing!!    
[smiley=cheers.gif] 
Graham


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## tony_rigby_uk (Nov 27, 2008)

Good Write up Grayham,

How are you finding it?
Any Engine lights on?


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## ian222 (May 4, 2007)

Ok so if there is no need for it why is it there?


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## T3RBO (Dec 9, 2003)

Much simpler write up for those wishing to do it :wink:


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## Grahamstt (Jul 22, 2008)

I believe that it controls the dv valve via the ecu for smoothness
Once you have a mapped engine the boost at part throttle is so much higher that it creates a jerky on off effect.
I havent driven it much since done so cant comment yet but I did find a split pipe which has eliminated a flat spot at 3300 - 3500rpm   unless it was the delete mod
No lights on dash either Tony, :roll: 
Graham


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## koskotas (Dec 1, 2008)

? How the mod going on ?



Grahamstt said:


> I believe that it controls the dv valve via the ecu for smoothness
> Once you have a mapped engine the boost at part throttle is so much higher that it creates a jerky on off effect.
> I havent driven it much since done so cant comment yet but I did find a split pipe which has eliminated a flat spot at 3300 - 3500rpm   unless it was the delete mod
> No lights on dash either Tony, :roll:
> Graham


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## Grahamstt (Jul 22, 2008)

So far so good
No lights on, does seem smoother at stop start traffic situations and part throttle lift off
Graham


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## JohnD (May 7, 2002)

I have had this mod for a while with no problems, I have one vacuum pipe going directly from the inlet manifold to the DV and another going straight to the fuel pressure regulator. From what I have read some engine variants have an extra valve and extra pipework associated with this. Mine's a BAM engine.

John.


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## Grahamstt (Jul 22, 2008)

Still going ok with no lights on dash  
Meant to say that mines an APX engine so I dont know what differences there are between them as far as the N249 is concerned


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## merloc (Apr 23, 2012)

Thanks for posting this guide.
It was a very easy job following your instructions.
Throttle response is better and a strange random flat spot that it had has now gone.
Thank you


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## UR_TT (Nov 8, 2008)

Thank you, this will land on the todo list!

Great write up!

[smiley=thumbsup.gif]


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## kazinak (Mar 23, 2010)

easy way :?: more like ''i have no idea how to do proper n249 delete'' way [smiley=dizzy2.gif] [smiley=freak.gif]

do it properly or don't do it at all :!: :!: :!: :!:

easy way : connect thee pipe together and remove everything else


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## Grahamstt (Jul 22, 2008)

This was done two years ago Kaz so was done a step at a time for those not wanting to risk complete no going back delete.

At the time there was a lot of neg comments about it so not a lot of people wanted to try it


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## kazinak (Mar 23, 2010)

bloody newbies bumped old tread :lol: :lol:


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## TTSPORT666 (Dec 1, 2011)

Kaz you done this mod then? would you recommend this? What are the downsides of this? why did audi spend money fitting it to the TT?

Does Wak have an opinion on this mod?

Looks a good mod from where i am sitting.

Damien.


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## Wak (May 6, 2002)

TTSPORT666 said:


> Kaz you done this mod then? would you recommend this? What are the downsides of this? why did audi spend money fitting it to the TT?
> 
> Does Wak have an opinion on this mod?
> 
> ...


1. It is an anti-surge device to open the DV before manifold vacuum builds up. = Its a good thing to have.
2. Anyone who says response is improved.... is logically incorrect, its whole purpose in life is to improve DV response and so they are just feeling a difference and making an misinformed opinion. 
3. The Reasoning of it being less to leak and go wrong? I've yet to come across a leak in the N249 Assembly its pretty reliable.
4. Curing flat spots.... hmmm logically there is no reason this has anything to do with flat spots under throttle so dont see any reason why this would help cure flat spots. ( unless there was a leak in it! lol ) 
5. The Little louder chirp you may hear when letting off the gas is the onset of surge just before the DV opens. = its not a good thing.

So everything about removing it is bad, However it does make the engine top more tidy and Ive personally gone through phases of removing it , refitting it and currently its removed. :roll: ( despite the points above)

But its best you understand, its bad to remove... but the engine does look better without and even the well informed may remove it and take their chances!


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## YELLOW_TT (Feb 25, 2004)

On the qS you can keep the N249 and still have a nice tidy cam cover just relocate it under the battery cover :idea: that's what I did


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## merlin c (Jan 25, 2012)

YELLOW_TT said:


> On the qS you can keep the N249 and still have a nice tidy cam cover just relocate it under the battery cover :idea: that's what I did


What a good idea [smiley=dude.gif] , I now have plenty of space where the air filter box was, now just a heat shield and cone filter, I may fit it to the back face of the heat shield and run all new red hoses and splice a new cable into the circuit...Thanks for the idea Yellow TT... [smiley=thumbsup.gif]

Off to the airport shortly for 2 days in Frankfurt with work, German ale and meat products....heaven... [smiley=wings.gif]


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## cookie (Mar 30, 2009)

Better still remove the bloody valve solder one of these in http://www.ebay.co.uk/itm/1-8T-20v-...arts_Vehicles_CarParts_SM&hash=item4166045534 located it anywhere you want as its alot smaller to hide and you've just done some weight saving as well as getting rid of the ugly valve


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## YELLOW_TT (Feb 25, 2004)

cookie said:


> Better still remove the bloody valve solder one of these in http://www.ebay.co.uk/itm/1-8T-20v-...arts_Vehicles_CarParts_SM&hash=item4166045534 located it anywhere you want as its alot smaller to hide and you've just done some weight saving as well as getting rid of the ugly valve


I guess you didn't read Waks post


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## cookie (Mar 30, 2009)

I have read Wak's post and understood what he said but end of day its my car and I wanted to completely get rid of it like quite a number of people have done now and there still running fine

End of day its like marmite either you love it or you hate it


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## TTSPORT666 (Dec 1, 2011)

Wak said:


> TTSPORT666 said:
> 
> 
> > Kaz you done this mod then? would you recommend this? What are the downsides of this? why did audi spend money fitting it to the TT?
> ...


Thanks Wak. Really appreciate you clearing that one up. I have no problem with how it looks etc. I don't run my engine without the plastic engine cover anyhow. OEM plus baby...  
Damien.


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## Wak (May 6, 2002)

After having done the cone filter recently and I'm hearing the surge so much more on gear change and so often, the n249 is back on.

It's much quieter now and doing what it should. 
IMO leave it on or work out a relocate option if you want to tidy up the bay

Sent from my iPhone using Tapatalk


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## Mondo (Feb 20, 2009)

'...or work out a relocate option if you want to tidy up the bay...'

If you work out such a place, do let us all know.


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## Wak (May 6, 2002)

Mondo said:


> '...or work out a relocate option if you want to tidy up the bay...'
> 
> If you work out such a place, do let us all know.


Job for another day, I had to get rid of the noise asap!


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## YELLOW_TT (Feb 25, 2004)

I have an idear just need to test it out :wink:


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## merlin c (Jan 25, 2012)

Mondo said:


> '...or work out a relocate option if you want to tidy up the bay...'
> 
> If you work out such a place, do let us all know.


Relocating mine next weekend in preparation for a lot of work at the end of July, will post pics as soon as I have done it, all comments positive or negative will be appreciated...cant wait for Kas's comments..... :lol: :lol: might be positive....


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## 1fast2liter (Jul 14, 2011)

i know raising this from the dead..

i have a problem with the n249 releasing boost on me anything over 15 psi and it wants to set it back to stock levels. i run a apr tune with 3inch dp forge dv forge tip and 2.5 exhaust. if i take the n249 out of the equation it will hit full boost no problem. but will have a partial throttle studder and inboost missfire or stutter. any ideas?


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## Mondo (Feb 20, 2009)

Can't help you with that, but I did relocate all those gubbins somewhere. Not the best pic but hopefully you get the idea.









Basically hid it under the plastic covers in front/to the left of the battery, zip-tied to a solid bar running across there. It's a bit tight but seems to work.


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## Wak (May 6, 2002)

Dis you have to leave the used bog roll in the picture?


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## Mondo (Feb 20, 2009)

Well, I was s#itting myself I'd do it wrong so... yes. :wink:

Be grateful it wasn't the used piece.


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## Gone (May 5, 2009)

So what is the issue with high vac in the manifold? Damage to the DV?

Looks like a job I can do for peanuts, which means it's allowed, and a good excuse to do the DV relocate


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## gizzy (Mar 3, 2011)

i recently did this doing it the kazinak way. Connecting the intake manifold vacuum line and the N112 Vac line to the DV line. 
Grahamstt's guide says to only connect the Intake Manifold Vac to the DV line, and seal off the N112 line.

Whats the difference and which is better ? Is there any advantage to sealing off the N112 line ?

I'm only doing a N249 Delete, I cant stand how the engine bay looks with it.
I have a Bailey DV and Revo Tune.


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## Mondo (Feb 20, 2009)

If you don't like the look but like the function just relocate it. Up front by the radiator, around the coolant overflow tank... there's a few places to hide the gubbins.


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## gizzy (Mar 3, 2011)

Well I already had one of the plastic hose connectors from the cluster of tubes broken, so decided to just take it out altogether. I am just wondering whats the difference between connecting both vacuum hoses to the DV or just the TB vacuum hose and top off the N112


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## dunsmod (Sep 6, 2005)

gizzy said:


> Well I already had one of the plastic hose connectors from the cluster of tubes broken, so decided to just take it out altogether. I am just wondering whats the difference between connecting both vacuum hoses to the DV or just the TB vacuum hose and top off the N112


 I know its a fairly old post but, just wondering the same.
Does anyone know what the difference between the 2 ways is and what one is best idea?
I,m ready to delete the N249 and wondering the best way to go as well. :roll:


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## brooksesi (May 8, 2012)

Th easiest way is to just buy some 4mm silicone hose, and run a line straight from the DV to the nipple the old hose used to go on the intake manifold.


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## dunsmod (Sep 6, 2005)

brooksesi said:


> Th easiest way is to just buy some 4mm silicone hose, and run a line straight from the DV to the nipple the old hose used to go on the intake manifold.


Hi, thanks. I've got the APX engine and its got a hose from the 112 valve also. Should i just blank this?
Thanks.


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## nordic (Apr 26, 2010)

On apx, N249 assembly has 3 way check valve, blank the tip that goes to N112 on the valve. Or if you're removing N249, then N112 can just hang with one tip not connected to anything.


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## dunsmod (Sep 6, 2005)

Cheers mate, I'll get onto this job as soon as ive got time. I dont think the 112 valve is doing much if ive got the power pulled from the SAI blower?
Cheers


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## nordic (Apr 26, 2010)

I may be wrong, but N112 controls the combi valve that opens fresh air flow into exhaust. Only a guess, if valve sees no pressure, the exhaust pressure may overcome the spring of the combi valve and leak the exhaust. Best to blank it all off.


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## dunsmod (Sep 6, 2005)

nordic said:


> I may be wrong, but N112 controls the combi valve that opens fresh air flow into exhaust. Only a guess, if valve sees no pressure, the exhaust pressure may overcome the spring of the combi valve and leak the exhaust. Best to blank it all off.


Chhers mate! 8)


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## Jonny1337 (Jun 20, 2013)

YELLOW_TT said:


> On the qS you can keep the N249 and still have a nice tidy cam cover just relocate it under the battery cover :idea: that's what I did


I'm sorry I'm resurrecting an old thread but was wondering if you could tell me what bits/parts you used to relocate the n249 below the battery cover?


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## YELLOW_TT (Feb 25, 2004)

Jonny1337 said:


> YELLOW_TT said:
> 
> 
> > On the qS you can keep the N249 and still have a nice tidy cam cover just relocate it under the battery cover :idea: that's what I did
> ...


You just need a couple of longer lengths of vac hose (I used silicone hose from eBay) and a length of cable to extend the wiring 








You can just see the hose coming out of the battery box in the picture


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## Jonny1337 (Jun 20, 2013)

YELLOW_TT said:


> Jonny1337 said:
> 
> 
> > YELLOW_TT said:
> ...


Thanks Yellow ...awesome engine bay ... More eBay shopping to do


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## HairyHamster (Apr 30, 2017)

What size of bolt and T pipe are used?


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## TT Tom TT (Oct 9, 2015)

Don't do it.


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## HairyHamster (Apr 30, 2017)

Why not tom?

Sent from my Vodafone Smart ultra 6 using Tapatalk


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## TT Tom TT (Oct 9, 2015)

No reason, delete yours and sell me it 8)...


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## SamDorey (Dec 31, 2016)

Some info on why not to delete the N249

http://www.audizine.com/forum/showthrea ... -not-do-it


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## ProjectMick (Sep 29, 2015)

As above - leave it in place or relocate it


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