Evo3 16G low boost/creep

[GSX_Dan]

Has anyone had problems keeping low boost with this turbo? I am having a very difficult time keeping this turbo at low boost above 5200 rpm. My exhaust consists of the Evo3 exh mani, Joe P. 2.5" tubular O2 w/external dump wastegate, 2.5" DP, 2.5" cutout mounted on off-road pipe, and stock catback w/ stock muffler.

Even when I run a straight vacuum line(T into the BOV) to the WG it holds 9psi to about 5200rpm then it makes it's creep to 14-15 by 7200rpm. The higher the gear, the worse the creep seems to be. If I open the cutout there will be more creep. I know this looks like a textbook WG/O2 restriction problem but if the turbo came with a 9psi spring then it should hold it there throughout the revs providing there is no restriction via the O2 housing and the external dump should take care of that right? I have also heard the EVO3 16g turbine housing's WG passage is redesigned for better flow not needing a 34mm flapper.

I have not tried to hold boost above 13 psi yet, because it always creeps to about 16 then I shut it down as my fuel system is reaching it's limits. I have tried using Joe P's MBC and an EBC and no luck. Is this a WG problem or what? If so any suggestions on how to correct the problem? Any feedback is appreciated, thanks.

 

[kpt4321]

You're creeping because the wastegate system as a whole cannot flow enough to control the boost. This is nothing new.

 

[GSX_Dan]

You're creeping because the wastegate system as a whole cannot flow enough to control the boost. This is nothing new.

How can my WG system not flow good enough? 9psi=almost no power + dumped tubular O2. This doesn't add up, especially when you put into account I'm running a stock catback, . The WG should have NO problem whatsoever from what I've been gathering based on other people's setups.

This could be a tuning problem, someone suggested. Although I'm running 11.5:1 A/F ratios(WB feedback) it's not a fuel problem, and my timing map is VERY conservative(AEM EMS basemap for MAP sensor conversion).

I even tried giving the WG it's own dedicated oversized line, and still creeps. This is frustrating.