project89

iTrader: (1)

i got the turbos back on, but right around 3 psi at part throttle my driver side turbo starts surging unless i lean into the throttle a bit more.
once i get above 5 psi the surge goes away.

i could understand both turbos having compressor surge but only one ???? wtf

u guys have any ideas on why only one turbo would be surging

327???

Possibly a minute manufacturing difference between the two, impeller clearance, cold piping restriction, air filter, etc...

project89

iTrader: (1)

well they are both garrett t3 50 trims and they spec out identical .48.42's the wheels are the same sizes.same sized wastegates and springs.

no air filters yet im just running screens on the inlets.

i have both turbo outlets y'ed into on 3 inch pipe, but one has alonger section before the y then the other .

i wonder if i switched the turbos from side to side if that would do anything, then if the same turbo surges on the other side i quess that would be a turbo issue then

junkcltr

iTrader: (1)

The longer section is not the problem. I have a twin setup with the same turbos feeding into one side of a horizontal IC. That is, one run to the IC is short and the other crosses under the damper to the IC. That setup does not surge.
I would test the wastegate actuators. Maybe one has a tear in the diaphram. That would cause the surge. Also, check for a leaking header gasket.

project89

iTrader: (1)

one wastegate was opening at 2 psi higher then the other. im gonna try shimming the one springs to see if i cant make up the difference in it.

going to twins has been nothing but a headache so far,almost thinking about selling off both 50 trims and just buying a dam gt35r with an ported s cover or a gt4088

junkcltr

iTrader: (1)

I always test my wastegate actuators when I first install them and I sometimes see a difference of 2 PSI to open them. It does not cause compressor surge. I am surprised you are getting a compressor surge. At one point I would get a screeching noise that sounded like a wheel was hitting a housing in one turbo. It happened at 3-ish PSI and above of boost. I checked out the turbo and it was fine. Finally figured it out.........exhaust header gasket blew out and would only screech / rattle when there was high enough exhaust back pressure.
How can you tell that only one turbo is in surge? By sound?

project89

iTrader: (1)

yeah just going by sound, it was deff only coming from one side

headers dont apear to have any leaks, but i am using dissimilar headers as far as primary lenght so i wonder if thats causing an issue

junkcltr

iTrader: (1)

Not sure what to say. If it were mine, I would try disconnecting the wastegate lines (and cap them) to the compressor side. Take it for a ride and control boost using the throttle and bring it up to 3 PSI and see if the wastegates are causing the problem or something on the cold side (BOV, connections, etc).

project89

iTrader: (1)

wastegate issue, i threw back on the crossover tube and the old single turbo, and swaped wastegates. i was way off, the 2 psi diff is were they started to crack open, full open on one was 7 psi and the other was 10 psi