What is an n249 bypass and question about turbo

Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Hi all, first off, are the cupra leon turbo's high pressure or low pressure? Next question, what is an n249 bypass? Is the mod something to do with the original recirc dump valve? sorry to sound so dumb guys. I'm used to jap stuff and not heard of any of this n249 stuff before. Cheers in advance. James
 

cupra_paul

Active Member
May 17, 2009
99
0
betwwen chair and keyboard
mate i was in your boat just come from a s13 if you dont want to get moaned at, type what you want to know in the serch box all you want to know is already in old posts up here just do a little reserch
 

Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Hi all, right done some searching around and still have questions. i now know how an n249 bypass is actually fitte and what it bypass's etc, but i still have another question. What actually is an n249 and n112 and what do they do. Couldn't find anything on the search option. Also are cupra turbo's low or high pressure? Thanks in advance. James
 

jonathanp

Full Member
Jan 5, 2005
736
0
Coventry
IIRC the N249 is there to assist in opening the DV and may also open the DV as a means to control boost. N112 is something to do with the secondary air pump and is used to heat up the cat

I'd probably class the cupra turbo as medium pressure I don't think they go much above 10psi as standard
 
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Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Cheers johnathon, so why would someone remove or bypass the n112. Whats the benefit of that? I may do the n249 bypass but i'm a bit sceptical about it as some have said it boosts better others have said you can hear the dv better and others said it runs worse! Really not sure what to do!
 
think of it as a restrictor or regulator to a certain degree, people have said there PSI has increased (only by 1ish but it's an increase :D) with it bypassed, i've only ever heard of a couple of negative opinions on this out of the vast amount of people who have done. Thing is if you don't like it and there is much not to like anyway, you can always revert back
 

Lodgey180

WoOoOoOsShH
May 3, 2008
1,046
0
Middlesbrough
www.mootr.co.uk
N249 Is a electronic device that contols the dv opening and closing.. you gain better throttle respons by doing the bypass aswell as quicker dv response. also i belive when you traction control kicks in ther n249 opens your dv which loses your boost ?!?!
 

tripdiesel

Leon Cupra R 225
Mar 21, 2009
162
0
Isle of Wight
N249 Is a electronic device that contols the dv opening and closing.. you gain better throttle respons by doing the bypass aswell as quicker dv response. also i belive when you traction control kicks in ther n249 opens your dv which loses your boost ?!?!

My TCS still kicks in a removes boost with the 249 bypassed
 

rickyb90

Speedbump destroyer!
Mar 21, 2009
84
0
NW Kent
Welcome to the forum:)

I had a S14 and still frequent the SXOC (still a member and will probably continue to be:)) and so its a bit of a different beast the Cupra compared to my SX.

I've done the aforementioned N249 bypass and TBH it makes a bit of a difference to the DV response as the DV is opened under manifold vacuum with no other intervention. I can't really say if it makes any difference to the throttle response, I haven't noticed anyway!
 

Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Rickyb90...seems like there's quite a few people that go from an sx to a cupra of some sort! Nice to hear from a fellow sxoc'er! I think i might do the bypass then and see how i get on with it. Like mentioned earlier i can always revert back. Cheers for the advice on how it all works. Getting an idea on how it all works now. Thanks everyone.
 

Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Sx_sideways remember seeing your name a few times on there! Nice to know i'm not alone! Ha ha! Do miss my sx but the leon cupra is fun drive and good compromise for a family car too!
 

cupra_paul

Active Member
May 17, 2009
99
0
betwwen chair and keyboard
yeah man, tell you what though these german motors are completey diffrent from the jap stuff! its like starting all over again


what ive found with them is there a dam sight more to mod than the jap stuff ie, fmic £600 remap £300+ induction kit £200 for a good one

what you done to yours so far??
 

rickyb90

Speedbump destroyer!
Mar 21, 2009
84
0
NW Kent
Its a bit of a learning curve:D

If you need a bit of guidance or a photo on what hose goes where just shout:)

The mods do cost more and I'm not really sure why. I can only assume the market is smaller as most parts will only fit Leon Cupras or the Cupra R.

The S13, S14/a and 15 market has a pretty big fanbase and so the demand for parts and modifications is high and so keeps prices down.

I'm glad my LCR has a FMIC fitted already but I really need to sort the handling out as the previous owner fitted coilovers and to cut a long story short, they're crap:thumbd:

As you say the boot is quite large compared to my 14 although I managed to get 3 sets of luggage plus several crates of beer for a weekend away in the boot!

There is also a remap on the car but thats causing a few problems at the moment and I'm in the process of sorting that.

My SXOC board name is turningjapanese
 

cupra_paul

Active Member
May 17, 2009
99
0
betwwen chair and keyboard
never saw you on there ricky prob cause i was in the s13 bit mostly , i ended up breaking the s13 to fund buying the lc, ended up making £4500 doing it like that. probably wouldnt of got £2000 selling as a car. do miss here somtimes though, normaly when its raining and theres a clear roundabout ahead !!!!
 

Essexcupra

Active Member
Jul 21, 2009
83
0
Romford, Essex
Dont remember seeing you on the sxoc! Nether the less still a fellow sxocer! I know everything seems so expensive. I remember when i got my first sx s13 you could get 300bhp for like 400 quid if done on a budget! One thing i will say is the germans do build good engines. Not got to worry about the death rattle (bottom ends etc!) not done much to mine... It's lowered on coilovers at the mo which dont seem to be too bad but ricky dont seem to like his. Has given it a very firm ride and have to practically stop to get over speed bumps. Got 18' rs8 alloys which i aint to keen on but seen worse after market cat back system enclosed induction kit which aint too bad and lovely set of front and rear door speakers. That good you would have thought there was a sub fitted! Apart from the mentioned thats all! Gonna do the n249 bypass see how that goes then forge dv and maybe chip and remap. Then the bigger stuff like fmic etc. And i think your right ricky, dont think there is such a demand for the leon stuff which obviously would make it dearer. Cheers for the offer of help rick. Feel like i'm a kid again as if i've never seen an engine before now i'm starting over on the german stuff. One question i do have rick is this, do early cupra 180's have the n249 or is the dv directly fed? Being lazy cant be arsed to pop the bonnet lol.
 
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