The blue spring is somewhere between 23 and 30psi? I don't understand...

Even if it is a 23psi actuator, that's entirely too high if you only want to run 25psi. What you need to do is get that actuator off and put the stock one back on. The stock 11psi actuator will give you plenty of room to tune without overboosting, plus it'll allow the ECU to drop boost way down if it needs to. A stronger actuator really has no benefit on the stock turbo anyway.

 

Seems like its stuck open from the way its boosting.


Forge springs are rated to crack at different pressures. The Blue should have been fine for my setup.

I dont have the stock one. The car had the Forge WGA on it when I bought it earlier this year. Im trying to avoid buying a stock one unless Im certain that its the issue. Im running out of options so that may be next to try.

 

Describe for me what you mean by "straight wastegate" and how you went about routing the boost hoses to achieve this state. I just want to make sure that we are on the same page please.

 

Ran the vacuum line from the turbo outlet directly to the wastegate.

 

If it was stuck open you wouldn't build any boost. You can get a stock wga for probably 50 bucks or keep overboosting and blow your motor. If your 100% sure that is not the bcs or something in your vaccum line then it has to be the wga. Do you have a friend with a evo with a stock wga? If so swap them out and see what happens.

 

I was thinking if the flapper wasnt seating correctly then the turbo would overcompensate and build more boost.

Don't know of anyone that's willing to swap to try it out. And im taking it easy until i can resolve the issue. Hell, there's only 1-2 counts of knock. I've checked all lines and fixed all boost leaks. The Forge WGA with the blue spring and 0 preload shouldn't hit 31lbs.


Update: Just found out that my shop has a stock Evo X WGA on hand. Talk about luck. Im gonna try it out on Tuesday. Im praying it fixes the issue.

 

Yes I understand how wastegate actuators work and how they're rated, but one spring doesn't have a 7psi spread that it could open at. Is it a 23psi, or is it a 30psi spring? If you don't know, then how do you know if that spring "should have been fine"? Like I said, even a 23psi actuator is entirely too stiff if you only want 25psi, and especially on the stock turbo.

Get yourself that stock actuator the shop has and never, ever go back to that Forge.

 

Yeah. I don't know. I called and the guy at Forge told me that the blue spring should be fine for my setup.

I'm crossing my fingers that the stock one solves the problem. I'll post back on Tuesday to let y'all know.

 

I need to make sure that we are in consonance on certain specifics. When you write terms such as, "....zero preload....", and, ".....straight wastegate..."' are you meaning that your boost controller is totally disconnected and out of the loop completely, and that you have connected a separate and new length of 4mm rubber hose directly from the WGA nipple to the nipple on the compressor discharge tube and finally that you have adjusted the turnbuckle on the end of the actuator rod to the point where the hole drilled into the flat slides freely on and off the peg on the flapper valve's pivot arm? Thus, adjusted you should be getting a fairly low boost reading equivalent(11#) to the turbo's base spring pressure with that particular actuator.

I personally don't trust the AEM True Boost controller and/or the newer generation Forge "piston-style" actuators.

 

On the stock actuator, yes around 11psi. He's on a Forge actuator and doesn't actually know what its minimum pressure is.

 

Yes and yes. When I say "0 preload" Im referring to having the turnbuckle at the point where it slides on and off easily. And "straight wastegate" being just as you stated... WGA nipple to compressor nipple and no boost controllers.

And my TruBoost gauge is nothing more than a standard boost gauge now.

 

So, we put it on the lift and found the problem. The O2 dump tube from the DP is capped off (welded shut). Removing the DP now to cut it and weld a pipe back into it like a divorced DP is supposed to be.

 

Haha who would do that lol. I would find the guy who owned the car before you and kick him in the d*** lol.

 

Seriously... Who would do that and for what purpose?

 

The phrase "WARNING - DANGER TO MANIFOLD!" was doubtless running through their heads.

Rich