gorillazfan1023

iTrader: (1)

I previously had a thread, "Why is my boost so saggy". Which didn't yield any results. I concluded that my wastegate (Internal) was defective. Thirdgen was kind enough to let me use one he had. Excited by the thought that I would finally have power for more then a few hundred rpm I slapped it on and went for a datalog...Attached are the disappointing results that followed.

Basically I still can't hold boost.
I have;
-Switched turbos
-Switched manifolds
-Gone to a bigger exhaust
-Installed VVTuner (tried changing the settings and am currently running it on the base DIY supplied map)
-Moved my wastegate line from post throttle plate to the coldside of my intercooler
-Switched wastegate cans

I'm at all loss now. Short of an EWG and EBC. As you can see in the log it hits ~11psi by 4500 then drops to ~5.5 by redline.

Any suggestions would be appreciated.
Thanks,
-Patrick

18psi

iTrader: (76)

I assume boost leak test yielded absolutely zero leaks?

thirdgen

iTrader: (26)

I'm thinking it could be that internal wastegate flange. Ditch that and go EWG.

gorillazfan1023

iTrader: (1)

Correct. As far as I could tell I couldn't hear or feel any leaks. I even used a stethoscope.

Leafy

iTrader: (1)

Is it possible that his turbo has such a massive wastegate flap that you need a stronger iwga spring to hold it closed against the exhaust pressure?

gorillazfan1023

iTrader: (1)

I guess it's possible. I have this style waste gate. 5 Bolt to 2 5" V Band Turbo Downpipe Wastegate Adapter | eBay

It appears to be sealing fine just can't hold boost, I was hoping the new actuator would fix it, but it did not.

Leafy

iTrader: (1)

Grab a weak extension spring from from the hardware store and see if that helps the sag?

gorillazfan1023

iTrader: (1)

Hmm I could try that. Not sure how I'll hook a spring up. Also don't know if it matters but I couldn't even maintain 5psi

Leafy

iTrader: (1)

Just hook it up between the rod on the wg flapper (where the iwga connects) and the bracket for the iwga (or the barb fitting on the iwga).

y8s

iTrader: (8)

have you done a "disconnect the boost control" test?

in other words, if you pull all the vac lines off the wastegate actuator and do a run (KEEPING YOUR EYE ON THE BOOST GAUGE TO PREVENT BOOOOM), does it build fast or slow?

gorillazfan1023

iTrader: (1)

Haven't tried, but I will. I had boost cut set at ~15psi and cranked the rod full tight once and I did hit it.