hey i have the forge 007 dv for the tt from ttstuff.com its really cool but anyway it came with the spring kit two discs and 3 springs Do they change the sound of the whoose? they all have different tensions so i think they would change the sound but not sure?

 

if its what im thinking of then its the tunning kit and yes it changes the sound

 

Yes they change the sound of the "whoosh", lol. However, that is an indirect effect of what the spring is really doing. The spring tension, i.e the stiffness or softness of the spring, determines when the bov will start to open. If the spring is too soft, it will easily open you may not acheive the full boost you are capable of making (diverter valve "diverts" the air even though the wastegate is functiong properly). If the spring is too firm, the valve will not open in time to properly vent the reverse flowing airflow when the throttle plate closes (i.e when you take your foot of the gas pedal to shift), which causes compressor surge. This is not good for the turbo and over time, if occuring frequently, can cause the bearings inside the turbocharger center housing to fail. What happens is the reverse flowing air makes its way back into the compressor housing and you have two opposing forces, one is trying to spin the compressor in a clockwise fashion and the other is trying to spin the compressor in a counter-clockwise fashion. You can probably imagine how this is bad for the turbo and puts unwanted loads on the center housing thrust bearings. You might be able to hear compressor surge if you have an intake or upgraded plumbing. It sounds like a bird chirping and is a high pitched sound almost like a flutter. This is the main reson the bov/diverter valve is there, to prevent compressor surge. Although the sound they make is pretty cool to most

 

so how do i know which spring to use--i'm using the one that came with it already inside---its green= i read somewhere that if u can push the valve open with your thumb then its ok--mine is not to stiff or 2 loose--so i think i'm good. i just put my modshack airbox in today and eveything sounds ok- the diverter valve seems to be louder but doesnt sound like a high pitch bird or anything So do you think i'm good? also ..it would then make sense to change the spring if your running higher boost so the spring can handle it? right now i'm running stock boost

 

You should be fine with that spring.

Just an FYI, the only sure way to tell is to make a boost leak tester, affix it to the compressor housing inlet and hook up an air compressor. Clamp the throttle open and undo the hose that returns the air into the intake so that the diverter will vent the air into the open air. You want to run the compressor up to whatever boost level you are reaching (i.e. 16psi) slowly. Feel for any air coming out of the valve as you raise the compressed air amount, which would indicate your spring is too loose (dv is opening when you don't want it to). You see you only want the dv to open when the throttle plate closes, which is what its function is. Since we are doing this test with the throttle clamped open (or someone sitting inside the car with the gas pushed to the floor), the dv should never open. If the dv is opening with the throttle wide open while you are making boost, the turbocharger has to work harder (under greater load) to produce the wanted pressure in the intake manifold, in this case 16psi. The dv is, in effect, leaking off boost pressure making the turbo have to work much harder to produce the desired boost level. This puts wear on your turbo and decreases life if repeated many times. This is from my past experience working on and building turbocharged DSM's (eclipse/talon/laser). For our Audi TT's, I'm sure the set-up you have will work just fine and if you don't hear anything unusual you're running fine. I don't want to make this sound like a big deal, just trying to spread a little information. Hope this helps.

By the way, are you pleased with the Forge kit? I may consider this for my newly acquired TT. [sm=smiley20.gif]

 

Be sure to check the diaphram inside the diverter cuz they can tear sometimes. Thats why they give you a couple of them. I had the forge but when I went to get my car chipped there was a fault code that showed up when they hooked up the the diag port. But I wasnt getting a check engine light. We changed back to the stock diverter and the fault went away. We switched back and forth a couple of times and each time the forge gave the fault. So I went with a Bailey diverter, and good to go now. Oh the diaphram tore on mine too.

 

I just installed my forge 007 yesterday and this question has been on my mind as well, here is my experience so far:

With GIACx and a 710n valve I was spiking to @20~21 psi and holding @ 15

With the Forge and green spring I was Spiking to 15 or so and settling at 10 (felt very slow compared to before)

I read alot on vortex about being chipped and switching springs, it seems the green spring will only handle 15psi where the yellow will handle 20 so I put that in, now I am spiking to about 19~20 and leveling off @ 15, but this valve seems to hold the 15 longer.

For your application I think the green spring is fine, search for forge DV in the vortex 1.8t tech forum for more info.

 

The springs are rated as follows:

green - 5-15
yellow - 15-23
blue - 23-30
red - 30+

The shims can be used to further fine tune the valve.

 

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Wierd, I run GIAC X tuning and I run a blue spring in mine, however my gauge only reads that I spike at 22psi, and hold at 20. I wonder if I should go down a spring to the yellow one? Everything seems to run fine, I dunno just wondering if anyone had any opinion.