sparky

iTrader: (1)

I'll lay it out for you:

1) Disconnect the MBC.

2) Connect a 4mm hose directly from the compressor discharge nipple to the WGA nipple.

3) Adjust the length of the actuator rod to the point where the hole in the turnbuckle slides freely on and off the peg on the flapper valve's pivot arm.

4)Take the car out for a WOT run in 4th gear. Monitor boost gauge. Note indicated boost level. Assuming proper gauge functionality and no boost leaks, this gauge reading is the true base(unpreloaded) wastegate spring pressure.

5)Report back!

sparky

iTrader: (1)

I am wondering if your particular Forge WGA is the older diaphragm style unit or the newer piston style type. Do you happen to know?

Also, it sounds like you are pretty handy with tools so you understand that you have to loosen the backup nut behind the turnbuckle before rotating the turnbuckle, right? You don't want to rotate the entire actuator rod....just the turnbuckle along the threaded end of the rod.

sparky

iTrader: (1)

Also, what is the peak boost pressure that you are trying to run?

sparky

iTrader: (1)

Jumping ahead a bit....let's say that your base pressure tests out to actually be the 11 PSI which you are assuming it to be. Then you'll need to dial up the preload level incrementally by rotating the turnbuckle inward clockwise a turn or two at a time. Retest after each rotation(s) and further raise the spring pressure in this fashion up to your peak target boost level.

The reason that you are going to do this is to avoid assumptions. Through this procedure we will once and for all establish whether your WGA is functioning properly as delivered from Forge. Also, we will know at the end whether or not your MBC is functioning properly.

sparky

iTrader: (1)

I am not real crazy about the newer piston-style Forge WGA's. I prefer their original diaphragm type actuators.

The 18 PSI rating of the spring is the PSI at which the actuator goes full open. It actually starts to open and is partially open supposedly at 14 PSI, although I think that is really lifting earlier.

My experience with the Forge units is that the actuator rod length is usually too long as delivered for certain combinations of housings. Remember that the actuator has to be a universal fit for all possible combinations of 16G turbos whether they come configured with the 9.0, 9.8, or 10.5cm turbine housing. So, the actuator rod has to have sufficient reach and range of adjustability to accommodate all the housing pairings.

When you say that yours is properly preloaded and tightly adjusted as to actuator rod length it may just be that the actuator rod is too long and needs to be trimmed. The actuator rod may be bottoming out inside the turnbuckle. Have you checked this?

sparky

iTrader: (1)

There. Now you have enough to keep you thinking and busy for a while. JaJaJa I'll check back with you later.

MyronGainz

iTrader: (6)

Hahaha thanks for the lengthy posts and throwing your ideas at me!
Let's get up to speed.

1) So it IS in fact a piston type WGA. I've checked the O-rings inside, they're both in tact and properly lubricated.

2) The MBC is off of the car. The WGA is connected to the turbo directly with a 4mm hose

3) The reason i assume that the wga is preloaded correctly is because I essentially followed your instructions before I made the post. The WGA was preloaded really tight, yet still had about a 1/2" of adjustment left on the actuator rod before bottoming out.

4) I first installed the WGA with 0 preload (installed so that the turnbuckle slid off the pin with no resistance, then gave 6 half-turns downwards). This yielded 12psi of boost to redline. I then spun it down to where the turnbuckle hole was halfway below the wastegate pin. This net me 17-18 psi of boost.

5) The car held 18psi of boost to redline for about 3 minutes worth of driving, then the boost literally fell to 15psi, then 12psi, then 10 psi... within the space of 30 seconds. There was no modification done to the wga, intercooler piping, etc during this time. The car was in motion when this happened, this is why i assume that the preload is still correct

I am personally beginning to suspect the turbine itself of going bad.

cfdfireman1

iTrader: (11)

what BOV are you running?

MyronGainz

iTrader: (6)

upgraded to Evo IX metal

sparky

iTrader: (1)

Do you still have your original factory actuator on the shelf in the garage? If so, bolt it up just for comparison's sake. Or, if you can get your hands on a buddy's known healthy actuator borrow it.

sparky

iTrader: (1)

Also, since the boost dropped anyway why don't you try further turning in the turnbuckle again. Try two full turns more. Or bottom it out and just keep your eye on the boost gauge.

sparky

iTrader: (1)

The Fireman may be onto something. If your DV is uncrushed it may be lifting enough to vent those three-four PSI.

sparky

iTrader: (1)

If it was me I would just try cranking the turnbuckle down some more. If it is at 10 PSI now then do three to four full turns.

MyronGainz

iTrader: (6)

First thing I tried tonight was using the stock boost solenoid. Got nothing from it

Logged the car tonight with the turbo nipple venting, and the WGA disconnected from a boost source. Theoretically under this condition I should experience "infinite" boost, correct? The car peaked at 170 load. If I'm correct, this would mean that there is no boost leak in the system

Using rough, early evoscan estimates, 170 load corresponds to ~10psi.. which puts me exactly where my boost gauge reads. If I'm correct, this means that despite my lower boost readings, the car isn't leaking boost.

It's also very important to note that i found a good bit of oil in my UICP. Most of it was settled near the couplers, but I notice no blue smoke at WOT, no puffs of smoke when I let off the gas or anything of the sort. I assume most if it is from the air breather and lack of catch can, so I won't use it as any form of diagnosis.

MyronGainz

iTrader: (6)

I replaced my stock plastic bov with the metal IX one, and tested it leak free to 24psi... So nope

I will try cranking down the WGA some more tonight. But I'm not quite sure how much further I can really go