n249 bypass

rikwheeler

Active Member
Apr 23, 2006
131
0
Lincoln
www.rikwheeler.com
n249.jpg

I've just done the bypass and was very simple to do on my LCR.
I'm now wanting to redo my engine bay with new red hoses and I'm getting a bit confused as how to do it.

Can I redo it like in this pic? Also, can I re-direct the FPR hose to the same hose?

ChangingEngineHoses.jpg
 
Mar 26, 2007
2,020
0
S.Wales
I seem to have done this completely differently from everyone else, my N249 bypass is as simple as disconnecting the N249 from the system entirely (but leaving it electrically connected) and running one silicon hose from the dv to the spare port on the underside of the inlet manifold on the left hand side.
 

rikwheeler

Active Member
Apr 23, 2006
131
0
Lincoln
www.rikwheeler.com
Thats what I did mate. You will see my N249 valve is cable tied in the top left hand corner of my pic.
Just wanting to know if I can disconnect it from underneath the inlet manifold, block the hole up and connect the tube to the connector on the top right of the inlet manifold instead and then T-piece the other tube to it as well. Think it would look cleaner
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
I seem to have done this completely differently from everyone else, my N249 bypass is as simple as disconnecting the N249 from the system entirely (but leaving it electrically connected) and running one silicon hose from the dv to the spare port on the underside of the inlet manifold on the left hand side.

Your inlet manifold is different from an LC though. There are a few ways of doing it but so long as the old hoses from the top of the DV and the vac resevoir are plugged and you have a direct or t'd connection from inlet manifold to DV, you can't go wrong.

The method I used above was the easiest way I could see of doing it on a single intercooler LC setup.
 

cruising03uk

street sleeper
May 10, 2006
133
0
north london
Hey Bret, is that the whole 249 bypass mod? one single hose?

i have not done it this way dont know the benefits of this way or the way i done it but i just put a t piece in the frp pipe and ran the t piece to the dumpvalve and then blocked off the n249 pipe that once went to top of dump valve. car just alot smoother just feels like its got a very little bit of boost all the time alot more responsive. GREAT MOD
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
i have not done it this way dont know the benefits of this way or the way i done it but i just put a t piece in the frp pipe and ran the t piece to the dumpvalve and then blocked off the n249 pipe that once went to top of dump valve. car just alot smoother just feels like its got a very little bit of boost all the time alot more responsive. GREAT MOD

The only difference is that you've kept the old vac hose from the intake manifold to the FPR. I replaced mine as its rubber and they don't last very long. The vac resevoir is no longer needed but it does no harm to keep it, I just wanted easy access to the coil packs so I removed it.
 

mkm250680

Active Member
Feb 6, 2007
138
0
Leicester
I would'nt mind having ago at this but it looks well confusing with different pipes and different engines do you just take the pipe off the manifold and extend it and attach to the top of the DV? but what do you do with the pipe that is taken off?
 

cruising03uk

street sleeper
May 10, 2006
133
0
north london
The only difference is that you've kept the old vac hose from the intake manifold to the FPR. I replaced mine as its rubber and they don't last very long. The vac resevoir is no longer needed but it does no harm to keep it, I just wanted easy access to the coil packs so I removed it.

so am i right in saying that the original line that goes to N249 should go straight to dump valve? therefore bypassing the N249 or is it just the same as putting a t piece in before fpr and blocking off the pipe coming out of the N249 this is the only thing that is confussing many.

thanks[B)]
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
so am i right in saying that the original line that goes to N249 should go straight to dump valve? therefore bypassing the N249 or is it just the same as putting a t piece in before fpr and blocking off the pipe coming out of the N249 this is the only thing that is confussing many.

thanks[B)]

correct; that's how I have done it :)
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
the way you did it; just took the pipe that goes from the inlet mani to the n249 and routed it directly to the top of the dv.
 

cruising03uk

street sleeper
May 10, 2006
133
0
north london
the way you did it; just took the pipe that goes from the inlet mani to the n249 and routed it directly to the top of the dv.

i did it the other way put a t piece in the fpr pipe and blocked off the n249 pipe coming out of the n249 but no management light an runs smoothly nice dump noise too.
 

DannyC87

Rubbing is Racing :-)
Mar 4, 2008
3,459
0
think either way does exactly the same thing; just getting inlet mani vacuum to the DV via different routes! mine sounds a lot better since the bypas; has a cheeky little chirp at the right revs :D
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
so am i right in saying that the original line that goes to N249 should go straight to dump valve? therefore bypassing the N249 or is it just the same as putting a t piece in before fpr and blocking off the pipe coming out of the N249 this is the only thing that is confussing many.

thanks[B)]

The only N249 related hose that I've removed is the one to the vacuum connection on the top of the dump valve. I've plugged it with a bolt and that way the N249 is none the wiser that its not there.

In the simplest terms, I've Tee'd into the FPR vacuum hose and I'm running the top dump valve connection from this. That way its straight from the manifold and the ECU has no control over the dump valve.
 

cruising03uk

street sleeper
May 10, 2006
133
0
north london
think either way does exactly the same thing; just getting inlet mani vacuum to the DV via different routes! mine sounds a lot better since the bypas; has a cheeky little chirp at the right revs :D

yea sounds nice smooth all the time and nice chatter when letting off sort of like a waste gate from rally car :funk:
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
think either way does exactly the same thing; just getting inlet mani vacuum to the DV via different routes! mine sounds a lot better since the bypas; has a cheeky little chirp at the right revs :D

:yes: Exactly correct. Mine does the chirp thing too. Drove down to Awesome for my Milltek Turbo back to be fitted today, lots of fun! :D
 

cruising03uk

street sleeper
May 10, 2006
133
0
north london
:yes: Exactly correct. Mine does the chirp thing too. Drove down to Awesome for my Milltek Turbo back to be fitted today, lots of fun! :D

is it alot louder turbo back compared to just cat back or standard i thinking of gettin 3inch downpipe and race cat or de cat but not sure due to not being able to have it too loud due to going to work an waking everyone up done that before an not pushing car down road first lol:lol:
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
is it alot louder turbo back compared to just cat back or standard i thinking of gettin 3inch downpipe and race cat or de cat but not sure due to not being able to have it too loud due to going to work an waking everyone up done that before an not pushing car down road first lol:lol:

Its louder under load but about the same at idle, probably a bit of a deeper sound. Mine has 200 cell sports cat and seems to be fine. I'd suspect that a de-cat would be very loud and you always have the hassle of having to change the downpipe for your MOT.

Going by the VAG-COM logs I did tonight versus Saturdays, I've gained about 10bhp :D Once I get a new MAF I should have some decent power again :)
 

Cupra Ross

Breaks things............
May 15, 2005
1,380
1
Edinburgh, Scotland
No problem, I was getting a bit confused too. There are so many different takes on this but the underlying theme is that you need to remove the ability for the ECU to open the dump valve. This is exactly what we've done.
 
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