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Hi guys. Was just wondering what this mod actual does. And whether or not anyone has actually done it and noticed a difference? Have seen that a few people have done it over on the seat cupra network, but couldnt actually understand what the idea of the mod is. If anyone could inform me, i would me ever grateful Wouldnt mind having a go at doin it if its worth while. Cheers guys

N249 is the Boost Pressure Control Valve, so I would guess it allows the turbo to provide more boost?

Anyone else have more info?, im intrigued about this mod myself

Heres a link to the page i found over on scn http://www.seatcupra.net/forums/showthr ... 673&page=6 . They also say that reversin the dump valve makes it react faster, allowing it to hold boost longer. Is this a bit dodgy? Surely it would be mounted the other way from standard if it was better? Am confused lol

Ok, this forum does not get many views any more.

Have a look at VW Watercooled (Australian VW site), I've put up a thread about it on there.

In summary, the N249 is a device not seen on older 1.8T's that is designed to provide vacuum to the Diverter Valve from the Vac reservior (item above spark plugs).

Normally when the throttle body is open, there is no vacuum in the intake manifold (as you are producing boost), so the diverter valve can not be opened. The N249 allows the ECU to bleed boost when you are on the throttle).

IMO, if you want a faster car than stock and have already chipped it, its a cheap easy mod. Easiest way to bypass is to run the vac line from the intake manifold to the diverter vac nipple direct, loop the intake and outlet of the N249 back on itself.

Easy to test.

One nice benefit is the diverter opens a little more cleanly, a slightly sharper diverter / blow off sound. It may add a little boost too.

I would think when 'reversing' the dump valve, they are referring to changing the ports used on something like the Forge diverter, so instead of being 70% divert, 30% blow off, its 30% divert, 70% blow off. IMO, the diverter should not be blowing to atmosphere as it does not sound particularly good and you are loosing some air that the engine is expecting. Pulling a little airflow from the process is likely to create more lag between gear changes, even if its such a small amount you don't notice it.

Thanks for that matey, has cleared a few things up has that. Well i havent had mine remapped yet. Going on holiday in a week or so, so will be looking at getting a stage 1 custom code when am back. Is this mod only any good with a mapped car then? Would it make a stock car run crap or just no difference at all?

It is not something I would recomend at all, unless you have done a fair bit of other work. the mod does not change the power delivery much, so I would not look into this unless you've done a few other things.

First would be chip, then intake and dump pipe / exhaust. If you are interested after that, FMIC, etc, then these sort of mods.

Cheers.

Nice one. Cheers for the advice buddy. Looking at getting custom code stage 1 in bout 4 weeks time, and then savin for the miltek turbo back. There just so bloody expensive lol