Attn: All DBW

[karmad]

Was wondering if anyone has tried that N249 bypass, was just reading about it in b6 forum and wanted to know if the any b5 have done this and with wat type of results


here is the link for the b6 guys

http://www.audizine.com/forum/showthread.php?t=231928

[redflagquattro]

i just read the B6 post..im gonna try this over the weekend, ill let you know how it goes.

[1poynt8tee]

Hm...kinda wondering about this myself now, one of the nipples was on the verge of breaking when I replaced a hose on the IM. I wonder if this will improve my partial throttle feel.

[onepoint8tee]

Yeah I did it. Boost seems to be more resposive to the gas pedal. A less DBW feeling, if you will. Thats about it. The reason I did it was to diagnose a boost issue, and I just kept it that way. So the DV vac line runs straight to the intake mani like on AEB engines, and i jsut looped the n249.

[TQMB5]

there are alot of reads on ripping out alot of the check valves and sytem in the b6 section, keep searching, if you cant find i will find them tomorrow morning

[boostedup]

i read the b6 post an im gonna try this. sounds like everyone that did it had a good response.

[biketsai]

I think this is what my friend was talking about in order for my DV fluttering to go away.

Im a little confused now, what do I do with the intake manifold hole now that used to be connected to the n249?

[boostedup]

I think this is what my friend was talking about in order for my DV fluttering to go away.

Im a little confused now, what do I do with the intake manifold hole now that used to be connected to the n249?

the vacuum line from the intake manifold goes DIRECTLY to the DV. then loop the n249 with some hose, viola. (some say you can leave the n249 without looping it but i would be safe and loop it to keep anything from getting in there.......

[GetBoosted84]

I'm going to do this also. I want to loop the SAI Solenoid (N112) also at that time and cap off the double t line running to it that feeds the vacuum reservoir. Should simplify some of the vac. lines I have going so that should make my life a little easier when I have to diagnose boost leaks.

I'm a little worried about the CEL because of the SAI not having the right amount of flow but I figure this way I can give it a shot and its easily reversible for emmisions.

[biketsai]

the vacuum line from the intake manifold goes DIRECTLY to the DV. then loop the n249 with some hose, viola. (some say you can leave the n249 without looping it but i would be safe and loop it to keep anything from getting in there.......

Will it be alright if I still have my boost gauge running off of this DV line?

[biketsai]

K, I just finished, and with the line originally coming from the Intake manifold to the sensor, I just used that hose to loop it. Pretty simple.

[GetBoosted84]

K, I just finished, and with the line originally coming from the Intake manifold to the sensor, I just used that hose to loop it. Pretty simple.

What did you do with the T line that feeds the vac canister?

[biketsai]

What did you do with the T line that feeds the vac canister?

Nothing. All I did was remove the DV line, and moved that to the front corner intake manifold spot.
Then removed the hose that was originally on the intake manifold and used that to plug the original spot where the DV line hooked up at.
does that sound right?

[GetBoosted84]

So you left that T open to atmosphere? That might be a leak considering it connects to the N112 also. I would check by just starting the car and seeing if you feel vacuum from that hole to make sure.

[biketsai]

So you left that T open to atmosphere? That might be a leak considering it connects to the N112 also. I would check by just starting the car and seeing if you feel vacuum from that hole to make sure.

Ok, I know that there is a hard line (T) that comes off of the valve and is connected to the other valve. I didnt touch that one.

[GetBoosted84]

Ok, I know that there is a hard line (T) that comes off of the valve and is connected to the other valve. I didnt touch that one.

Ok so that one is still connected to the N249 Valve? Maybe I am misunderstanding.

And here is a diagram I found of how to bypass it:


From the looks of the diagram you would want to plug the hard line and run a vac line to both of those ports while leaving the side port opened up (or plugged also I guess).

EDIT:

Here is what it should look like when all done. This person removed the N249 ad N112 valves:

[biketsai]

Hmm, it doesnt look like I did it in the diagram. It makes sense once you think about it (unless I am completely wrong). From the description from others, it seems like all you do is make the DV go straight to the intake manifold.

[biketsai]

Thats how I did it.

[boostedup]

Hmm, it doesnt look like I did it in the diagram. It makes sense once you think about it (unless I am completely wrong). From the description from others, it seems like all you do is make the DV go straight to the intake manifold.

DV straight to the front of manifold. alot of people have done JUST that.and no problems.......no looping or anything. as long as you keep the n249 still plugged in the ecu will not give a CEL

[biketsai]

DV straight to the front of manifold. alot of people have done JUST that.and no problems.......no looping or anything. as long as you keep the n249 still plugged in the ecu will not give a CEL

Basically what I did.
I just used the end of the hose that came off of the intake manifold and plugged the spot where the DV used to be.,

[boostedup]

notice any difference in driving? i haven't done this yet, just read the thread thoroughly......... everyone that did it says boost comes in quick, and some even say that got more boost...

[Kaytek]

Edit: Sorry didn't see the post before mine.

[biketsai]

Yea I went out earlier and gave it some boost but didnt push it to 23lbs (what my MBC is set for).
I dont wanna say its "more responsive" because that might be all in my head. But it seems like the sound of my T28 is a little different when i am giving it 1psi, almost like I can hear the turbo a little louder like a k03.

Edit: Ill do a couple pulls later today to see if I notice anything.

[boostedup]

i just did this mod in about 5 minutes flat.

i have a 2001 1.8t with open air intake and Apr 1.0bar and always spike at 17-18 max.

that said, after this mod i seriously hit the 17-18 mark in first and second, and 20psi in 3rd and 4th for the record i've never hit 20 psi in ANY gear on the APR software before. And it seems like the boost does come in quicker.(this is going on me hitting full boost in 1st and 2nd which never happened).

i was also hoping this would STOP my DV flutter, it seemed like it helped but did'nt stop it. any ideas? reverse DV? i think it's on there normal right now don't remember if i ever reversed it.

[boostedup]

FYI i used this diagram exactly......very easy DV line straight to front of IM, then loop the n249 with the line that WAS going to the IM.

i had a boost gauge so i put that in-line with the line from DV to IM

[Naudi_Mat]

So after reading all the threads on this, I decided go out and do it. Took all of about 5 mins to do. I went out and did a few pulls, and I noticed a slight increase in throttle response. And it does feel like the turbo spools a tad quicker. But I notice that boost dies off earlier in the higher rpm's. So I will run this setup tonight, and part of tomorrow, and If I don't like it, I will prolly just throw it back to the stock setup.

As for my car, I'm APR state 1, APR R1 DV, intake, FMIC, and exhaust.

[7speed]

This mod is really those people who are running BT

[biketsai]

i just did this mod in about 5 minutes flat.

i have a 2001 1.8t with open air intake and Apr 1.0bar and always spike at 17-18 max.

that said, after this mod i seriously hit the 17-18 mark in first and second, and 20psi in 3rd and 4th for the record i've never hit 20 psi in ANY gear on the APR software before. And it seems like the boost does come in quicker.(this is going on me hitting full boost in 1st and 2nd which never happened).

i was also hoping this would STOP my DV flutter, it seemed like it helped but did'nt stop it. any ideas? reverse DV? i think it's on there normal right now don't remember if i ever reversed it.

Yea it helped my flutter, but didnt make it go away. Did you loop the original IM hose back onto where the DV was connected tothe N249?

[boostedup]

Yea it helped my flutter, but didnt make it go away. Did you loop the original IM hose back onto where the DV was connected tothe N249?

that's exactly what i did.

This mod is really those people who are running BT

i am not BT and i would recommend it to ANY DBW. it's a free increase in performance, throttle response, boost onset, and raises your current boost settings. (still safe, because GIAC software hits 20+psi)

[flynnr]

hey everyone... im a noob when it comes to audis but this looks like a safe adn easy mod that i can do in my time off...


ANYONE WANT TO TAKE Good Pictures an write up somethign for the DIY section?? i would like to do this but all of those diagrams with the red and blue dont help me too much idk i jsut havent been under the hood enough on this car to know all the terms and stuff...

that would be really awesome and helpful to new audi owners like myself... thanks a lot

[karmad]

hey everyone... im a noob when it comes to audis but this looks like a safe adn easy mod that i can do in my time off...


ANYONE WANT TO TAKE Good Pictures an write up somethign for the DIY section?? i would like to do this but all of those diagrams with the red and blue dont help me too much idk i jsut havent been under the hood enough on this car to know all the terms and stuff...

that would be really awesome and helpful to new audi owners like myself... thanks a lot

I second DIY guide, someone should make one

[biketsai]

It would be impossible to takepictures

[Poopie]

don't need pictures. just open up the hood and go to work. there are 3 10mm bolts holding on the plate that the n249 mounts to. thats really all you need to know.

[GetBoosted84]

I agree with poopie, really no need for a DIY but if you do want one... here is a complete DIY of a vacuum cleanup with N249 and SAI bypass covered also (with photos):

http://www.audizine.com/forum/showthread.php?t=235106

[Militant-Grunt]

I did this, look for my thread ill be posting pics tomorrow.

[boostedup]

there you go i made a DIY.

no but seriously if you can't do it from that diagram, then don't attempt it. It's as easy as it looks,took me 5 minutes FLAT. all your doing is re-routing 2 vacuum lines........

[B5A4Kevin]

I did this mod last night in less than 5 minutes with nothing but long needle nose pliers and a phillips screw driver for the cover and the coolant expansion reservoir. Instead of looping the hose, i removed it completely and capped both ends instead. not too much of a performance difference but i am not chipped or bt. i did, however, notice 4th gear boost is even faster when going WOT at 3k (near instant), and 5th gear spikes to 13 instead of the previous 12. I'm not sure but it seemed like the DV seemed quieter when venting but it was also pouring rain. This does not seem to be too much of a performance mod and a placebo effect may be causing perceived gains.

The following is just speculation as I'm just thinking out loud.

I believe the reason the n249 was factory equipment is to extend the life of the stock diaphragm style DV as the solenoid will only open when it sees vacuum thus preventing possibly damaging boost pressure from pushing on the other side of the valve, which may cause it to tear. bypassing the n249 is now allowing boost pressure to access the DV and the observed gains may be due to better sealing of the DV by having the pressure to hold it tight in place.... again speculation. This may be detrimental in the long-run as the constant switching from boost to vacuum may over-exercise/wear away at the DV causing it to tear. I'm not sure if this would have as much of an effect on the piston style or updated 710n's but it is something to think about.

[GetBoosted84]

I did this mod last night in less than 5 minutes with nothing but long needle nose pliers and a phillips screw driver for the cover and the coolant expansion reservoir. Instead of looping the hose, i removed it completely and capped both ends instead. not too much of a performance difference but i am not chipped or bt. i did, however, notice 4th gear boost is even faster when going WOT at 3k (near instant), and 5th gear spikes to 13 instead of the previous 12. I'm not sure but it seemed like the DV seemed quieter when venting but it was also pouring rain. This does not seem to be too much of a performance mod and a placebo effect may be causing perceived gains.

The following is just speculation as I'm just thinking out loud.

I believe the reason the n249 was factory equipment is to extend the life of the stock diaphragm style DV as the solenoid will only open when it sees vacuum thus preventing possibly damaging boost pressure from pushing on the other side of the valve, which may cause it to tear. bypassing the n249 is now allowing boost pressure to access the DV and the observed gains may be due to better sealing of the DV by having the pressure to hold it tight in place.... again speculation. This may be detrimental in the long-run as the constant switching from boost to vacuum may over-exercise/wear away at the DV causing it to tear. I'm not sure if this would have as much of an effect on the piston style or updated 710n's but it is something to think about.

I just did this mod tonight too. I figured while I was in there re-circing my BOV I would rip it out to simplify my vacuum lines a little bit more.

As for the eventual ripping of the diaphragm in the diverter valve... that would suck for people that run one of them. Glad I have a BOV without a diaphragm in it.

[boostedup]

i did notice my dv is a little louder when recirculating........