# 710N's in reverse direction - any harm??



## Uberhare (Jul 30, 2003)

I've read numerous posts about the pro/con of running the DV in reverse. Some say its really hard on the diaphragm and will cause premature failure while other claim it's perfectly safe and actually allows for slightly quicker boost pressure relief. I've encountered a situation where I have to install the DVs in reverse direction because the two hoses off the Y-pipe are a little too short (Samco hose kit). I can make the connections if reversed but not in normal position. Am I going to cause problems or should I look at a different solution?
Hose(s) in question. It's the smaller blu/black "bent" hoses leading from the DV which directs boost back into the intake:










_Modified by Uberhare at 10:04 AM 1-17-2008_


----------



## GLS-S4 (Jun 6, 2005)

*Re: 710N's in reverse direction - any harm?? (Uberhare)*

What boost pressure are you running ?


----------



## Uberhare (Jul 30, 2003)

REVO 91 octane chip on stock K03s. I haven't hooked up my boost gauge yet, but I imagine boost spike around 21psi with constant full boost around 16-17psi. I'm worried the constant boost pressure against the face of the diagram will cause the diaphragm to rip and leak.


----------



## Uberhare (Jul 30, 2003)

I could rig up a splice off each hose to extend their reach but that would entail the use of a metal or plastic splice tube which cuts down on the inside diameter.


----------



## GLS-S4 (Jun 6, 2005)

*Re: (Uberhare)*

I've seen running DV's in reverse done before too. My only concern with running in reverse is if the boost pressure (esp spikes) exceeds the DV spring cracking pressure. If it did, the diaphram would open and dump boost back into intake when it is not supposed to. Maybe try a pressure test on the DV dump port and see what pressure it cracks compared to your max boost pressure.
It would be a wierd scenario if the DV's leaked only during boost spikes. There would be a temporary boost leak that would drive N75 to compensate by closing the wastegates some more, which would cause the leaking DV to dump more, this struggle would continue until ECU called for less boost than the DV spring cracking pressure.
Just a thought... maybe VAG log 114 and 115 at the same time under WOT thru a few gears before and after the DV reverse install to see if N75 behaves differently under the two scenarios.
For extensions, shouldn't be an issue as long as ID of extension is not less than ID of DV tube.


----------

