I got an answer off ukmk1vs

In Answer to original question VVT on the 1.8T specifically was designed with Emissions and cold starts in mind. The 1.8T cars with VVT have wideband o2's and the non-vvt are all narrowband. You will not benefit from any performance from VVT in the 1.8T lump its a different ball game when you look at Vtec etc ect on the Jap cars.

Whats the narrowband bit mean then

I ordered a 007p valve today from Forge. It's due to arrive next Friday (wasn't that a movie also? ). I'll let you know how it works once I got it.

In the meantime I spoke with the guys from dupre motorsport, they told me that the turbo is custom built (?!), not some standard model. Now I'm waiting for an answer from them about any info they can give me, like the boost it makes...

Try & find out who mapped the car. It cant (shouldnt) be a custom turbo & still a stock map

Also in the log book it will have the previous owners name & address, try directory enquires for a number & give him a call

Dupre could also contact whoever they sold the turbo to & ask them if its OK for you to call them.

You really need to find out what you have bought before you start tinkering or it could all end in tears

I know that Dupre mapped the car. It's on the receipt: software optimization, turbo, intercooler, exhaust, cam shaft and some other miscellaneous. Now I'm waiting for their response (didn't get it today unfortunately).

You might find that the engine comes on song more at 4000rpm with the engine being variable valved. I can feel it kick in about that point, but it is usually smooth though. Have you got a tuner with a rolling road to see what its doing?? If its not the DV, then it could be possible caused by a bad map

I get the kick around then too, vag-com logs back me up. I never felt this kick with my first remap it is only since my second more agressive remap. I always assumed it was just the map style. :confused:

Ok, forge 007p arrived and installed. The noise is gone . Also, could be that I'm just imagining it, but the car seems to run better, and by this I mean pull better and get to high revs quicker and smoother. The only thing still left is that sometimes under hard acceleration in high gear, even though the car goes, it seems to lose boost from time to time (I hear a "psst"). But it might have been me raising the foot off the pedal a little... didn't have enough road and time to test thoroughly. Or it could be that I need another spring in the dv because of the changed turbo (now the green one's inside). All in all I'm pretty pleased with how it runs and especially now that I change gears it only goes "fffft" instead of the "woosh-woosh-woosh" I had before.

Tomorrow I'll do the suction test on the old DV, I've to clean it, there was a little bit of oil on its lower tube.

Thanks for all the help, I'll be back with more impressions soon as I get a chance to take the car out on open road.

ps: I forgot to say, the fuel consumption seems also better (instead of 18l/100km heavy foot now i got around 11.5) . Am I just imagining it or can a broken DV have anything to do with that?

Edited 19 December, 200817 yr by jmf

I finally got a chance today to go out on some open road. Even though the noise is gone, the power hiccup problem is still there. It only appears 3rd, 4th and 5th gears and what happens is under hard acceleration, I get power-no power-power-no power. When the hiccup occurs I can hear the turbo "discharge", like a "psssst". Could it be that the green spring in the forge 007p is not stiff enough and I need a stiffer one?

Also, I noticed that a hose is shot, I don't know if this is the correct english wording, but here they call it the "carter gases hose". I ordered a replacement, but could this also be the source of the problem?

It might be worth getting a readout of how much boost you're generating so you can decide on the correct poundage for the spring - the yellow one works from 15lbs upwards, which I'd imagine yours should easily be generating after all the other work the car has had.

Whereabout was that hose and what did it connect to? It's certainly a fascinating translation

The mechanic to which I first went said you can't read the boost with vag-com off this engine. I've a feeling he just didn't know. Can you please tell me how to read the boost or make a log of the engine parameters on the road with vag-com? I'll probably buy a cable next week and do it myself. :P

Regarding the hose, I luckily have one of the pictures I took of the DV where you can see it. Check out the attachment. I also tried looking it up in ETKA, but maybe I have an older version or something, because ETKA gives me a "breather hose" that looks like a regular hose, while this one, as can be seen it the picture, is Y-shaped.

There's a section on Ross-Tech's site about using the measuring blocks, and one of the images actually shows a boost pressure readout. I don't own vag.com so can't advise you on the specifics, but have spent a bit of time looking through it in order to work out whether to buy it - there are people here who are vag.com superstars and can probably walk you through it

Ross-Tech: VAG-COM Tour: Measuring Blocks

As for that particular cracked hose.. that's probably one of the most common problems reported on the site

Ok, but what does that hose actually do? And what's it called in english, so I can search the forums for it? Can it be responsible for loss of boost?

"Tomorrow I'll do the suction test on the old DV, I've to clean it, there was a little bit of oil on its lower tube." Did it: old valve was shot, failed the suction test. Oh well

Edited 21 December, 200817 yr by jmf

You're defo gonna need at least a yellow spring in there, judging from the mods. I've got a Performance Torque Stage 1, which was supposed to be good for 14psi, but the car is in fact running at 15-16 and spiking at 20. I tried a green, and it couldn't hold the boost well enough for my liking, and was jolting on lift off. The yellow spring has pretty much cured it.

You can definately measure boost with VAGCOM. Alternatively, fit a boost gauge.

I'm actually looking for a boost gauge and Ron Clubley's ones looked very cool, but unfortunately the guy he got them from is no longer on ebay :(.

Tuesday I'm meeting with a guy who does custom maps and he will read my existing map to see what it's about. I'll also try to convince him to make some boost logs on the road, then (hopefully) I'll know exactly what spring I need.

As a side note, I took another drive on wet asphalt and 2nd gear esp is on all the way under acceleration. On one of these occasions, while the esp light was on, there was a sudden "jolt", like the fuel was cut off, then it was back on. Was this the ASR kicking in maybe?

The map guy meeting was postponed for January :(

However, I managed to do a vag-com log on the road and i got:

Boost pressure = 2300mbar, which means actually 1300 mbar, which is about 18.8 psi. So definitely need a new diverter valve spring.

Torque (don't know if this is real, but it's what vag-com says) = 398nm.

Also, I cleared the "boost pressure control valve n249: mechanical malfunction" error and it didn't come back, so I guess it was because of the fauly dv.

Here's the spring set - not sure what shipping costs will be like though!

Forge Motorsport | Alloy Fabrication

The torque figure sounds very high, I would have thought somewhere around 300-330nm with just a remap?

Torque sounds good for a car with a big turbo.

I went to yet another mechanic today (I'm trying them all ) to try to fix my irregular idle problem. He showed me the throttle body thing, it was squeaky clean (but we only saw one side, because he didn't take the thing off, just took off the rubber hose that goes into it). So that's not the problem. He said he can't see anything else wrong with the car, checked vaccum hoses all ok, vag-com reported no errors. Conclusion was that maybe the changed camshaft is the problem.

Any other ideas as to what could cause idling fluctuations (they're small, like 50-100 rpm, but annoying)?...

Try increasing the idle speed by 50-100. My guess is the hunting at idle will be much reduced.

What is the default (factory) idle speed for 1.8t auq?

Today, while looking under the bonnet, i saw what appears to be a hanging electric cable behind the engine, towards the passenger compartment, near the turbo. The cable has an end with 2 pins and some molten plastic around it, probably from the heat. I've attached a picture (sorry for the quality, crappy camera at night), do you have any idea what it is and where it should go?

note: in the meantime i set it on the air conduit's isolation to try to protect it from further heat. It seems to stay lodged in there and not "fall" so far...

edit: i've upped two more clearer images of it.

Edited 6 January, 200917 yr by jmf

Almost looks like a thermocouple going onto the turbo!

Could be the wiring and plug for the N75 I guess.

That top pressure pipe and heat shield are not standard. Could you take some more photos of the engine bay please, then maybe we could start to figure out what mods there are. Try and get a shot of the turbo, and intake.

My brake pedal lights switch died today, resulting in the brake lights staying permanently on. I went to the dealer and replaced it, but took the oportunity to raise the car on the elevator and look at the loose wire. We looked together and saw no particular place to connect it to. It was coming out of what they said to be "the primary lambda probe", which was a bullet-shaped thing on the engine block. Also, there was a similar thing near the catalytic converter, and they said that probably the car was modded to not use the regular lambda probe and this new one near the cat was installed. Does this seem to make any sense?

ps: they also ran a diagnostic and it showed no codes (outside the brake switch) and also they said the lambda block returned correct values.

pps: I also borrowed a camera, tomorrow in broad daylight I'll take some pictures of the engine.

Edited 10 January, 200917 yr by jmf

Took some photos today. Next time it's up on elevator will try to take some from underneath.

And another set. Please let me know what you think.

From what I can see (and little I know), only the Forge valve and the big metal pipe behind the engine are out of the ordinary (btw, what is that pipe for?). Also, in one shot you can see some tubing which goes to the FMIC afaik.

I also took one of the boot, because I saw those two black metal bars which aren't ther on a friend's 1.9tdi. Are this standard only for RS?

Thanks a lot!

I thought it had a FMIC? i cannot see it.

The boot Strut braces are standard on the RS

Yea, the picture didn't make it past the screening process since it's not that good. I hope you can make it out in the attachment