
Originally Posted by
Drew-B6
Thanks a4darkness and diagnoticator!!! Your post are always informative, along with others on this forum. This along with face book are something I always check, I know lame... Also, what I am reading by turning your DV in reverse (diaphragm style) will allow for the DV to hold more pressure for longer right? That would be great as my K03 will boost to 21PSI then drops right off with the APR 1+ and lots of other mods. My 3rd and 4th gears are the best and will hold 21 PSI a little more that 1st and 2nd.
At what RPM is is dropping off Drew? If you're seeing 21psi that's not bad but with a K03 we're never going to see anything impressive past 5k. Yeah, with a FMIC on a cold day it'll stretch to 5.5K but still tapering. Small turbo is small.
After reviewing Diagnosticator's comments, I realize how confusing this might sound. I'll paraphrase.
General
* a stiffer spring, or a spring with more pre load, will cause the DV to open later and close sooner, in relation to intake manifold pressure
* the byproduct of this is acceleration that's a tad less sudden and more smooth, granted there's enough boost pressure to force a reversed piston style DV open soon enough
* a piston DV reversed will require a bit more pressure to open the DV
Factory Orientation
* with the DV in the factory position, only the spring stiffness determines the DV's opening / closing behavior
* this is one reason the reversed orientation is functionally superior, as the characteristics of the DV are not solely reliant on the DV's spring vs the charge air
Reversed Orientation
* regardless of boost pressure, in the reversed position there is always a lot more force holding the DV closed
* this allows for the use of a light spring tension (compared to a DV installed in the factory position)
* combined with a light spring tension, the forces that open the DV are mainly generated by the boost pressurized air as the DV cracks open
* since the boost generated forces don't have to oppose a stiff spring force to open, the DV opens quickly
* then as the throttle is opened after a gear shift, boost pressure is reapplied to the DV aided by the closing spring force
* this closes the DV at the same rate that boost pressure increases in the intake manifold
TL:DR
Stock orientation is fine for either, relies on force of spring / rubber (diaphram) vs charge air pressure to open/shut.
Reversed is harder to open DV, yet also controlled by flow of boost air pressure
Reversed is quicker for a diaphragm style at low boost and will shorten it's life at higher boost.
Reversed for piston allows for a less stiff spring to be used and can increase responsiveness / acceleration + smooth things out

Originally Posted by
kneel
PM me i have a forge splitter DV for sale. Not posted yet though.
Neil to the rescue. Do you have any cool stuff for me?

Originally Posted by
olstyn
Anybody got anything to say about the synchronic DV? Ever since I first heard about it, I've been curious, but it doesn't seem to be widely used. On the surface, at least, it seems like a cool concept, but I'm far from expert, so I'd like to hear some real world experiences.
Nice try Jenny.
Tell you what. Send me one of your universal application DVs. If it's the beans I'll write the most thorough review you've seen and everyone on AZ will buy one. Everyone. Even the 3.0 guys.
Bookmarks