Hi,

installed HKS GTII turbo on my Evo IX. Worked fine but after some time boost went down (on the same settings). I though it's because of a weather (getting hotter) but mechanics pointed out actuator shaft is bent (see picture below). Is this because overheat? Should I replace whole actuator from Garrett turbo (which one? How many PSI?) Should I replace wastegate as well?

Thanks!

Anton

 

That rod heats cools and bends--was noted in earlier posts when the turbo came out. Tighten the buckle and check it periodically. After a short while it will stop and everything will be fine.

 

As I've suspected So no need to replace anything?

 

I think there was problems with the wastegate flapper warping and not sealing.
Re-apply your preload, and check your boost levels.
If the boost is down from where it was, this could be the problem.

 

Seems a common problem, both the 7460 I have installed have actuator problems.
I think HKS have to solve these problems...

 

Look up fellow EvoM member R/TErnie's posts on this subject. He ran one of these turbos for a while not too long ago and I think he fixed the issue.

 

You mean on this thread:

https://www.evolutionm.net/forums/ev...-failures.html

 

Hmmm. Close but no seegar.....Ernie started or posted extensively on an earlier thread with respect to his installation of the GTII, and the subsequent adjustment process involved in setting up the WGA properly. I'll have to search for it myself. As I mentioned, it was an earlier thread than the one that you found.

I think that as a practical matter if I am remembering correctly, he found that the segmented actuator rod with multiple threaded adjustment ends needs to be readjusted after the initial install and preload adjustment. The adjustment rod either stretches, bends, or loosens which throws your initial preload adjustments out the window requiring a second recalibration. Otherwise your wastegate spring pressure gets flabby and turbo spool up suffers.

Like I said I'll try to search it up for you. Am I way off base, Ernie?

 

You got it

Re-tension the pre-load on the rod and pray that your flapper isn't warped.

 

Sir... YES, SIR!

 

OK, I've re-checked waste gate flapper and it's fine. Installed turbo back and everything was fine. Now I'm back to shaggy boost and if I turn boost off (programmatically or so) I have only .7-.75 bar in the whole range of 3000-8000 rpm. How much should I have on just actuator?

 

Your flapper is warped. Contact Forced Performance for their 3xmm replacement wastegate flapper for the Evo turbine housings.

 

If you say so I will. However I took off the wastegate completely and flapper does not look like it has any issues with it. Looks like any flapper on a low mileage turbo... Is there any way I can increase basic boost shortening the push rod? What HKS GTII actuator pressure should be? In the other words: how much should I expect in boost off position? Thank you!

 

If the face of the flapper valve is warped then it will leak even if you wire it shut. Shouldn't it? So, wire it shut with bailing wire or a turnbuckle and chain, or some such jerry rigged method.

Once the valve face is wired down tight onto the seat then take it for a WOT run. Keep your eye glued to the boost gauge and be prepared to backoff the throttle immediately.

At least this test will tell you if it is a WG puck surface flatness issue or an actuator rod tension problem.

 

Op may not be adjusting preload properly...

Op if you try sparkys method make sure you have boost cut enabled.