boost issues with forge dv

[WhiteGTI]

Interesting results Steve. This may be related, but I remember when you had your car rolling roaded recently you said that it only made 270lb/ft torque, which seems on the low side for an ED30. Do you think there is another explanation for your current problems?

Although, it seems that with the standard DV, your car is fine. How does it feel with the standard DV? All good? I'm only raising this because mine made 302lb/ft in December when I rolling roaded it, therefore suggesting that yours may be on the low side? 

[SteveS]

could be possible that the spacer leaked, it did look like with it fitted though my test it lost a minimal amount of boost, but i couldnt see it make such a difference to the torque...

with the standard, it does feel move responsive, so im very confused.

[SteveS]

it also seems, and this could be normal...
when going hard, boost builds up to say 21-22, then with the foot still down, it drops to around 19...

that normal?

[john_o]

Steve,

the boost profile is load and revs dependent so it can and does vary.
try WOT at 3 krpm , vs WOT at 5krpm and they wont peak at the same psi. (well APR doesnt anyway, at 3k I get 21 ish peak , at 5 k itll be 17psi)
on mine (apr not revo) , the boost peaks very quickly to 21 ish then almost instantly starts to settle at around 17psi.
Theres a graph on how the software peaks then troughs to find the stable boost pressure somewhere on golfmkv...
I think REVO has the same 'profile'
Worth also trying on/off on the throttle to see how the car reacts

You are starting to see how useful this guage is going to be for you 

[SteveS]

john, i believe i can see roughly what your talkin about. progressive does seem to make a difference..

[SteveS]

I have had a responce frmo Forge USA.

I've been trying to source a car to test but cars with the remote set-up are hard to come by here in the states.
 
You results are the opposite of what we've data-logged with our valve but all of our testing here in the states have been on cars with the compressor mounted set-up. The only theory that I have been able to come up with (barring some anomaly with your car or some limitation in your test procedures) is that the increased distance from the pressure source (the compressor housing)  that the lower valve nipple is drawing it's "constant" pressure source from coupled with the increase in volume and lower pressure of the recirculation arrangement on the remote set-up is lowering the amount of pressure immediately available to close the valve after venting.
 
To explain a bit further, in the compressor mounted cars constant pressure is drawn from the lower nipple on the valve and applied through the solenoid to the top of the valve, this clamps it shut until the solenoid is cycled. The compressor housing is going to see the highest pressure in the entire intake system. When the valve is located near the throttle body that pressure will be much lower. Also, when the solenoid is actuated and vacuum is applied to the top of the valve, the pressure drop in the remote set-up will be much greater and will increase at a much lower rate than that of the comp-mounted valve as the entire run of piping and the intercooler will have to be pressurized before the valve has enough pressure available at the lower nipple to clamp shut, not to mention that the close proximity to the throttle-body will create massive fluxuations in pressure that might be causing the valve to open and shut in odd ways.
 
If my theory is correct I think that a one way check valve installed between the lower nipple on the valve and the pressure inlet port on the solenoid might do the trick, it should be installed so as to only allow boost to enter the solenoid (or more importantly to not allow that boost pressure to drop when the solenoid is actuated). The longer the length of silicon hose the more volume of pressurized air that will be trapped which should be beneficial to closing the valve as quickly as possible. It might even be necessary to use a small reservoir to increase this volume. Something very small should do.
 
All a theory but it is all I can come up with.

I'd like to say thanks for the help i have recieved from Forge. The USA guys really seem to want to explain things, as above!

Now it may be my reading, but i get the impression these valves have been designed and tested on a GTI K03 Turbo and just altered slightly to fit the Edition 30 K04..?... could be wrong obviously...

Now if someone could clear that up a tad for me? i think hes basically saying because of the increased distance there is less presure to keep the DV shut TIGHT...

[john_o]

if it were me it would be taken straight off , fit the new revision DV and wait until someone can confirm its been tested propely in the K04 install.......
What do forge UK have to say as Im sure theyve tested it too  (crosses fingers) as they are the HQ
you have 2 now, so sell one on ebay , keep the other for later