vtraudt

On my 1.8T AEB, I have the ARP R1 (came with the car).
On my 2.7T (2002, 154k)), I still have the stock (Stage 2 tuned now)DV.
Knowing that the stock DV should be replaced (age, performance), I now have to decide which way to go.

What are the advantages/disadvantage of the alternative functional principles:
a) diaphragm (for example APR R1)
b) piston (for example Bailey)

For each principle, what are most preferred brands/models, also keeping cost/benefit ratio in mind?

Fungeneer

This guy did an extensive write up on the comparison you're looking for...

http://www.s4biturbo.com/art-dvtests.php
http://www.s4biturbo.com/art-dvtests2.php

If you haven't been on it before, s4biturbo.com has some good info

vtraudt

Thanks for the link.

I installed 2 Forge, in 'reverse' order; makes more sense to me to have the pressure side from the turbo 'hit' the bottom of the piston. Supposedly only difference is the 'sound' it makes in reverse vs. 'normal' direction. I don't hear a thing anyway (before and after the switch).

I installed the 'medium' springs (15-25 psi boost I think) since I am boosting up to 20 psi (stock K03 turbos, custom tune)

I did NOT feel, hear or see (data logs) a difference in performance between the stock and Forge DV!

vtraudt

By the way: Google Chrome identified malicious software being installed on these site?

rocktown61201

I wanted to get an APR tune, so I upgraded my throttle body boot and DV's with a set of Bosch 710 N's for my 2004 A6 2.7T. There were about $50 each and was told by the distributor that they would be good all the way up to nearly a Stage 3, before you get larger K04's. I've had them for about 3k miles now and feel i made a good choice. Also, remember the more expensive DV's will last longer, but need periodic maintenance.

beyondgrafix

Feel more response when i step on it. A little disappointed because the salesperson at APR told me it would sound like a blow off valve and got no sound from it.

PHOKNMUVN

DV's, diverter valves do not make noise.. they recirculate into the intake.... blow off valves make noise cause they vent into the atmosphere when they open to release the pressure.. im stage 3 and have been running with the forge DV's for 6 years now and not a single problem with them at all..