I say run a hose from the outlet nipple on your compressor housing to the WG actuator and be done with it. That'll give you like 9psi solid...and if it still creeps, your WG flapper is too small. Get a bigger flapper or go external.

Okay,

First off, I run a Big16G with a full 6-bolt 1G swap in my 2G. My turbo was creeping like hell I had it set at 16psi for the street and it would just build out of control. At the time I had a 14B turbine housing on it ported to 7CM size. So I thought that could be the problem, bought a true 7cm housing, ported it. Still creeping. Bought a TRE 34mm flapper, ported the wastegate hole, STILL CREEPING! So my last attempt, I made a wastegate flapper and went to town porting my new 7cm housing.


2 Steps to fix your creep without spending any money...

1. Bigger Flapper
To make the flapper is simple. Just go to an auto machine shop and ask to dig through their bin of old exhaust valves. They should just have a box of them. Find one that is AT LEAST 34mm. The one I have is 40mm, its the biggest flapper that will fit in a turbine housing, had to port the wastegate outlet chamber to let it sit right. Once you get the right valve, take out your old wastegate flapper and then on a grinder, machine the exhaust valve to the same dimensions as the old vavle (except diameter of course) Then right where the valve stem meets the bottom of the valve, take a cut-off wheel and grind the diameter of the stem smaller than the part of the stem above it. You have to do this to let the flapper rotate once its installed (If it doesnt rotate, it could stick half open, that happened to me on my first attempt before I realize you had to do this) So the final valve will look something like this:
___
| |
| |
\ /
/----- -----\
-----------------

Installing it is simple too. Take your cut off wheel and cut a slit down the top of the stem so the top looks like this:
_ _
|| ||
|| ||
||_||
\ /

Then when you go to put it in the housing, fit it through the pieces that holds it, make sure it spings freely and seats properly, then take a washer (Home Depot, Ace, Lowes) put it over the valve and take whatever you need to spread the top of the stem out until it siezes againt the washer and wont fall out. I've had this on my car no problem. (Open and close the valve multiple times just to make sure, its a lot easier to fix the valve if it falls out now than when its on the car)


2. Porting the wastegat hole

Do this after you remove the old flapper and before you put the new one it. Now when I first installed my bought 34mm flapper, I just opened up the diameter of the wasegate without porting the INSIDE of the turbine housing. This is crucial as a bigger flapper helps, but porting of the housing to better direct wastegate gas flow is the kicker. You just have to hog it out. (Make sure there are no right angles on the entrance to the wastegate hole) I actually ported the inside of the housing so much that when you looked through the wastegate hole you couldn't see metal behind it. The actual hole was the smalled point in exhaust flow. It's hard to describe and I should've taken pictures, but hopefully you get what im saying.



After porting, install your new flapper (A good way to test the flapper seal is to fill the O2 side wastegate chamber on the turbine housing with water and see if any leaks through. No water good shape, little water, still okay, any more, the flapper may not be flat and might need some grinding, or might not be seated well.)

Give this a whirl, takes a couple hours, but is well worht
Hope it helps,

Peace

Well hell, my pictures got all screwed up, just imagine everything in them centered, and thats what it should look like

possibly port your inlet on the turbine housing to make flow towards the wastegate more friendly...???? just a though

is that a 16g ported/clipped or is it a big16g stock mistu part?

its a small ported/clipped 16g, from buschur i believe. the inlet is ported.