Boost surge/Boost oscillation. Please help!

[ggmel333]

I am getting some serious surging at any throttle. I am using Profec-b II ebc set for 17-18psi and no matter what it is set to my boost will surge seemingly at random, one pull will be strong at 17psi next one bad. It will drop to about 9psi and almost instantly go back to 17psi. Change the settings a bit for 12 psi seems to be good but still surges by about 2-3psi. The only setting that seems to help is if the waste gates closed until 17 psi or what ever it is set at and as soon as the waste gates open the surging happens. Another thing I noticed is the surging/oscillation is less dramatic if I build boost above 3,500rpm.

I am thinking either the waste gates, boost solenoid, or BOV are bad.

[ggmel333]

Even with all settings turned to zero on the profec-b I still get surging.

No boost leaks either all ready tested that about 5 times.

[ggmel333]

Bump...

[MightyMouse]

voltage to the solenoid?

[ggmel333]

The solenoid seems to be working, the boost adjusts accordingly. Going to switch solenoids today. My lines to the waste gates are even lenghts.

[MightyMouse]

What is the gain set to?

[tigger]

adjust the wastegates to open at the same psi
If they are off even the slightest you will get surge because one turbo is tring to over power the other, balance the wastegates and your problem should go away

i see you have 13gs most likley in stock housings i would suspect the wastegate adjuster is set too weak on one of the turbos

[ggmel333]

Originally Posted by MightyMouse

What is the gain set to?

My current settings effect 55% gain 15% set gain 1.05 limit 5% warning at 1.3 this gets me around 13-14psi. This seems to be the best I can get it surging about 2psi. Other settings I surge about 7psi.