Boerge

If you use some kind of boost controlling device, i.e a electronic boost controller or a mechanical
device like Boxerfan just installed, then I assume the stiffer spring would not be necessary.
Am I correct?

Best regards

Boerge

boxerfan

The stiffer spring helps prevent the diphragm from floating. The factory spring is really weak. If you do get a 1.8 or 2 bar spring the effect is noticeable instantly.

Having said that... if you have a really accurate boost controller you will find that the air pressure assisting the spring can clamp the WG closed very effectively. Just try running the pressure line to the WG cap without control and you'll see what I mean.

What kind of boost controller are you using?

Adam Mowafy

would be to put a bolt through the wastegate cap. Costs about $2 to do, and once its done you have adjustable spring tension. you'll need a bolt, a nut, and a washer big enough to push down the spring .

Theres been a few writeups on this mod. "Birdmanmt" might be able to help. I know he did it.

Boerge

I have a Turbosmart E-Boost laying around, it seems very nice to have in the Audi.It has
built in trigger for injector/water, that is adjustable from the display. Also works as
boost gauge.
I am following in your footsteps here if you don't mind!
It would save me 50$ from not buying the spring, or I guess the bolt through there would do just as well.
I always thought I should install the controller on the line to the bottom of the WG,is it better to make it control the upper chamber WG pressure?
And if so, will I have to set the boost to 0.3 Bar, to add the springs 0.5 bar, to give me 1.8 bar?
What gives the best results?
I would prefer to set actual boost level on the electronic controller, hence I would prefer "traditional" install.
What do you think?

Boerge

boxerfan

I did the adjustable WG bolt as well. The thing is that the spring constant (k as seen in text books) is just that, a constant. Loading the spring does increase the force holding the WG closed, but the constant remains the same old weak one. This means that the spring will start to leak easier than a stiffer spring.

I currently have the 1.8 bar spring clamped right up as well. If you attach the pressure lien to the WG cap you will see the effect that adding pressure has to the spring. Putting full manifold boost pressure to the WG cap means that the WG will be clamped shut because the air pressure on either side will be equal undr boost and so the additional force provided by the spring keeps it shut.

I definitely recommend going with the 6th injector, especially if all you have to do is connect it to that controller. Where did you get that controller by the way?

Boerge

Very nice unit, bought on Ebay, brand new, for
350$, not cheap!
But I have seen them more cheap, and more expensive as well.
So my Q again, do I really need a stiffer spring if this unit controls the boost pressure that goes to the bottom WG?

Thanks
Boerge

boxerfan

That's your call. A stiffer spring will hold better, but you can get away with the stock one. I guess it really depends on how well that boost controller works.

boxerfan

Looks like it should work well for you. Is there a PN for that solenoid with the hose connections? That's a cool part.<ul><li><a href="http://www.turbosmart.com.au/AutoSpeed_%20e-Boost_Eval.htm">Review of E-boost</a></li></ul>