007p Reverse or Normal Fitment

[DontPanic]

Got a vagcom and a mate has the proper software on a laptop at his garage. EML shows on both as N249 mechanical fault. The vac pipe seems ok. It's silicon and runs to the N249, T'd for the boost gauge too. Ordered some new tube so I can do the whole lot again anyway as it all came with the car when I bought it and doesn't look the prettiest of jobs!

 

[8bit]

OK, also check electrical connection and the vac pipe that runs TO the N249, think it originates under the intake manifold. The pipes under there are known weak points too.

 

[DontPanic]

That makes sense. Ok, will have a look at the lot next weekend. New vac pipe should be here mid week. Cheers for your advice!

 

[8bit]

No worries, let us know how you get on.

 

[DontPanic]

Will do. Mate says i can use his garage too. Think he's as interested as me to see what's what. Took it for a proper spin today, DV sounds alot better in reverse, still prefering the 'ping' to the chatter...

 

[DontPanic]

Ok. Did the vac pipes today including the N249 by pass. Car still runs fine and now boosts to 20psi and holds at around 18. Reverse DV was definitely the way to go i feel but as its all good i see no need to turn it back the other way.
Next on the menu are the steering and tie rod assembly.... quite handy (but expensive) having a mechanic in the car when going for a run!
Thanks for all your advice and help, i'll be back soon for more no doubt.



Still need to make 3 more posts before i can put up pics of the car. Can't wait that long..!! Stick 'http' infront of this >>

://i1141.photobucket.com/albums/n594/DontPanic111/leon1.jpg

 

[Nautilus]

After reading a few threads about why i get chatter between gear changes am i right in understanding it is not good for the turbo? Because i have tried all the springs from green through to red and it makes no difference to the chatter at all, however the yellow seemed to have a little less chatter. Then i tried reversing the DV (007p) still with the yellow spring and there is no chatter at all anymore just a woosh. Does this sound right?? Will be doing the N249 by-pass next weekend too.

1. Any weird sounds are not good for the turbo. That's why I've fought them for years

2. Reversing the DV was the right step.

3. The spring, by itself, holds the piston / diaphragm only when not under boost.

4. When the turbo pumps air, the pressure in the large hose (charge pipe to DV) and the thin hose (manifold to DV) are equal, since they are both pressurized by the turbo. Not the spring, but equal pressure on both top and bottom of the piston keeps the valve closed under boost.

5. When throttle is released, there is vacuum on top of piston and boost pressure on the bottom, and therefore piston is moved against the spring to open and release boost.

6. The fact that in reverse orientation chatter disappears can only mean that with valve in stock orientation it opened too little and too late and did not release air quick enough, while now does. DV006 / 007 needs lubrication to run properly, it can seize, and it's much harder for the air to move it than stock plastic valve, and in stock orientation most of the pressure is taken by the O-rings, which are flimsy. In reverse orientation, boost pressure acted on the bottom of the piston (much smaller surface) instead of side, did not have anything to do with O-rings and aided the vacuum to open quicker.

7. There is a reason for factory fitment: plastic diaphragm valve is much weaker, and for stock boost pressure of 0.8bar is just right. Place a stock valve in reverse and it breaks. Add a twice as large metal valve with heavy aluminium piston and you need air pressure to open in properly.

~Nautilus

 

[EddC]

I used to get a bit of chatter, then I gave my forge diverter valve a service, runs perfect now, I just get a big 'whoosh' that turns heads in the street I'm such a child lol.

 

[Steely]

The 710n valve isn't inferior to the 007p like everyone thinks. Many 350bhp + cars Run the stock 710n valve without any issues.

 

[traumapat]

The 710n valve isn't inferior to the 007p like everyone thinks. Many 350bhp + cars Run the stock 710n valve without any issues.

Agreed... must be the biggest forum myth going