This N249 bypass mod, FAO all of those who seem to dont understand it..

[leoncupra2012]

I did this to my cupra 180 earlier, it took less than 10 minutes, i really cant see what the fuss is all about either now !



Step by step long winded guide, if you cant do it after this then either dont do it or get someone else to lol..

Basically all you need is about 3/4 a metre of 4mm internal diameter silicon hose like so -

So buy 1m

http://www.ebay.co.uk/itm/330671639150?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Then you need a plastic 6mm at each connection, t piece like so

http://www.ebay.co.uk/itm/270697911689?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Then look at this

http://i39.tinypic.com/11ikftk.jpg

1) Remove the black box (red number 3 in picture), which is being pointed at by the lime green arrow, 3 bolts, need a allen key to remove these.

2) Cut the rubber hose thats going into it (yellow arrow) and then throw the black box away (number 3 again), use one of the bolts youve just removed to remove the box, and shove it down the open end of the hose youve just cut (yellow arrow again) to bung it up.

3) Remove the top small hose thats coming off your dumpvalve (number 1 in red on the picture), shove another one of them bolts down the open end of that hose to bung it up.

4) Bin the 3rd bolt or keep it, whatever

5) Take your new bit of hose you got off ebay or whereever, push it onto the top of the dumpvalve to replace the hose you just removed/bunged up, it goes where the red number 1 is in the pic.

6) Remove the hose that connects the fuel pressure regulator to the inlet, this goes down behind and underneath, so first remove it from the regulator, (red arrow) if you look where it goes you will see, pull this hose off and discard it, its about 10 inches long and feels like textile/braided.

7) Take your new hose which you connected to the dumpvalve earlier ( red number 1 in the picture, and feed it down, under however you like and connect it to under the inlet where you just pulled off the old hose that ran to the fuel pressure regulator

8) So now your new hose should connect the dumpvalve to the inlet, what you need to do here is cut the new hose near the fuel pressure regulator, and insert the t piece to rejoin these hoses, then run the offcut of new hose you should be left with from the left over connection on the fuel pressure regulator

9) Slap yourself on the forehead after realising how easy it was and for posting 60 questions time and time again on how do it!

:D

[BEOWULF]

Good guide mate do u have to remove the black box i have just left mine on.

[leoncupra2012]

No but it seems pointless just leaving it on there looks better without it mate :)

[dixonsa13]

might seem a dump question but
what do you acheive by this bypass

[leoncupra2012]

Some say it holds boost better, mine definately felt smoother when boosting/coming off boost, when changing gear instead of the normal tshh its a lot more of a crisp quicker sound. (forge valve)

[dixonsa13]

well mines pretty much standerd under the hood apart from a drilled airbox but every ones on about the bypasses and just wondering what the benefits are to like the n249 and the sai bypass ect

[leoncupra2012]

Whats the SAI one? N112 or something? whats that do?

[dixonsa13]

secondary air intake and no idea thats why i asked lol im thinking bout the n249 bypass and plus it looks neater

[aaron-gardner]

the n249 bypass is a simple mod which just eliminates the ecu dumping boost at low throttle and sometimes it becomes faulty and starts dumping boost randomly and can cause jerky pull off. also it helps hold boost for longer. the n112 and sai bypass/ removal are a bit more complex and all require resistors ect.. to bypass. if after doing the n249 bypass you still experience boost issues then maybe a n75/n112 and sai delete is the answer but in my opinion keep it simple and just do the n249 unless you believe or know the rest to be at fault.
also weather or not your car is standard or modified the n249 bypass works but its best used on a uprated dump valve as the n249 is a protective measure against the stock dv failing.

[dixonsa13]

thanks aaron that makes alot more sense now think i might just do the n249 bypass

[leoncupra2012]

In my eyes and experience if somethings not broke then don't fix it, but with this being such a simple cheap effective mod that you can't really mess up, (ok i managed to bent the bit on my fuel pressure regulator a little getting pissed off the hose clip wouldnt come off ! :rofl: ) then simply why not ! :D

[ben450]

This don't cover the LCR though

[LlamaLord]

Does this mod also work for tdi 150?

[techie]

Does this mod also work for tdi 150?

No, you don't have a dump valve.

[leoncupra2012]

:rofl:

[Dudfield]

Pipes on order will be doing this hopefully next weekend. the little black box is flapping around so a great excuse to do it ;)

[leoncupra2012]

Should be bolted down by 3 bolts? lol

[Dudfield]

should be but all 3 plastic brakets snapped oh well lol

[dan23]

in the first pic why does the red hose come from the n75 and not the top of the dv

[aaron-gardner]

its just laid their lol. it does look connected to the n75 tho.

[dan23]

oh ok cool now i know how do this, thanks

[Dudfield]

well i done this tonight was really easy but i do need some clips at where all the pipes connects looks a bit loose

not driven the car yet but will find out in the morning

[dan23]

yep i done mine now but would like to also fit a boost gauge in the car so was wondering how to do it, am i right in saying put another t piece in the bypass and run it into the car then just fit boost gauge

[Dudfield]

thats what ive read but im sure someone will be able to confirm that

[dan23]

k thanks, will wait to hear

[dan23]

right since doing the by-pass i have noticed that my car warms up very very quickly, like by the time i drive out of the close and 800 yards up the road its already on quarter temp. any ideas ?????

[aaron-gardner]

Their I's no reason I can see why the engine I's. Warming up quicker from doing the bypass. You will either get reduced performance or limp mode doing it wrong. You sure you have done it correctly? Also I used a cross piece instead of a t piece for my boost gauge but you could just add another t piece near the other.

[dannygoodson123]

We need more guides like this! Done it 2day in 15mins. Was a piece of piss and i waa unsure it would make a difference but it boosts smoother and the forge 007p is much more audioable even on a standed air box setup. Thanks again.

[Tr1ck]

number 3. isn't that the rocker cover breather? if so why block this?

[dannygoodson123]

Nah its the pipe comin off the vacuum box.

[dazjstuart]

Right, I know what to do know and think I understand what the N249s for etc etc. However 1 little question, what do the 2 pipes you block with the bolts actually do, where do they go etc?

[Matty1986]

I have just done mine today, took 15mins! Will see what it's like later when I drive home!

[Marc-H]

Just done mine and was worth it. It didnt take that long to do the job either

[ashtec]

I just got a Leon copra r someone has done this to it in the past. I'm going to convert it back so any one wanting to find a home for there old hoses I'd be happy to do a deal.

[dandanibiza]

Do you only need the t-peice if your running a boost gauge? I've got an fr and i can't see why i Need 2 seperate pipes. I've just got one pipe running from the inlet manifold to the DV?

Also wanted to ask where everyone puts the n249 and n112 connectors once the resistors are in as mine are resting on top of the engine and getting rather hot

thanks for any replys.

[Klone]

Their I's no reason I can see why the engine I's. Warming up quicker from doing the bypass. You will either get reduced performance or limp mode doing it wrong. You sure you have done it correctly? Also I used a cross piece instead of a t piece for my boost gauge but you could just add another t piece near the other.

Have you got a picture of your setup pal?

Few people would be grateful, and maybe the OP could inlcude that pic in his post.

[admasiv]

great thread did it to mine today how easy only thing is after doing it ive noticed a very slight flutter and mean slight is this normal?

[Molehill_Mike]

Thansk to OP, used this at the weekend. Even with a B&W print :)

Only difference for me was I used 3mm not 4mm as I had shed loads in the garage.

Top stuff :D

[jamski]

Done this today easy job car feels a lot smoother
Thanks to the OP

[Dejavoo]

Just done this, thanks OP although my brain couldnt work out the whole t piece thing for a while and then it all clicked lol :)

[bigfella2901]

does anyone have a guide on the LCR n249 bypass?

[stefduff]

Great guide, did mine yesterday. Cant honestly notice any difference but the dyno says 3bhp haha!

[Gaz5350]

does anyone have a guide on the LCR n249 bypass?

Here you go sir

http://www.seatcupra.net/forums/showthread.php?t=215866&highlight=n249+bypass+guide+LCR

[Rhys-69]

Will this bypass work on an aum engine??

[mc funbot]

Who wants the n249 bypass doing this week or weekend I'm doing a guide the correct way. I've done LOADS and fed up of seeing other in the net done wrong feeding crappy info to others ill do it free will even do Sai if needed. I'm in Northampton.

[dazjstuart]

Who wants the n249 bypass doing this week or weekend I'm doing a guide the correct way. I've done LOADS and fed up of seeing other in the net done wrong feeding crappy info to others ill do it free will even do Sai if needed. I'm in Northampton.

Are you saying that the guide in this thread is wrong?

[mc funbot]

Yes very wrong.. Who will help me. I'm sick to death of reading shite. I need a car that's all. And I'll to the guide.

[dazjstuart]

Works fine for me! Are you meaning doing a proper delete with resistors and all that? A decent guide for that would be good. All the guide on this thread is showing is blanking off the weird little tank thing which is fine for me and a lot of others.

[mc funbot]

Yes a full guide ill so the lot n249 Sai I don't mind. But I think it needs doing these are a lot of half assed guides from what people think is right.

[dazjstuart]

Fair play, although I don't think its fair to say this guide is wrong, it does exactly what it says, it bypasses the N249. Removing it altogether achieves no more than bypassing it, apart from tidying up your bay a bit. Saying all that I would still be interested in seeing your guide though!

[mc funbot]

This guide only dose half you don't need to poke bolts in to anything. What's dose will not gain anything apart from removing the black box there is more that could be dont. As its only getting pressure from the FPR not the correct pressure from the inlet :)

[dazjstuart]

Fair enough! I look forward to reading your write up, lots of pics please!!

[mc funbot]

Loads of pics mate, same as my build thread.. It's the best way.

[Hamzilla]

Hi. I've done the N249 but I want to remove the whole SAI. I have a catch can fitted but its all a bodge job. I would really appreciate it if you could help sort mine out. I live about an hour away.

[mc funbot]

here you go guys this is how it should be done!
http://www.seatcupra.net/forums/showthread.php?t=372006

[turbo_scotty]

Cheers helped me out a lot !