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

 

Do they share a BOV? If not I bet there is a difference with the opening pressure. Also did you verify everything on the turbo's matched after you got them back? Housings, wheels, etc?

 

i did the rebuild on the turbos myself,the compressor and turbine wheels are identical, so are the housings. im using a pair of t3 50 trims off a saab.

as far as the blow off valve i only have one

the turbo outlets come down to a y into a single 3 inch pipe to my intercooler.

im running 2 38 mm ebay wastegates, i was gonna swap the turbos from side to side and see if the surge follows the turbo to the other side but im gonna swap out the gates from side to side instead.

im thinking maybe the gates are opening differently there both suposed to have 7 psi springs in them and i have them teed into a turbo xs hpbc and tunred the boost upto 12 psi for now,

 

The gates would do it. I think the turbo that the gate is open on would be the one surging against the air the other turbo is providing. If that makes sense.

 

Don't forget, at that low of a pressure ratio, once one surges it releives the system pressure so the other doesn't have to. It's not logical that both turbos would surge at that low of pressure. In fact it's not logical that either turbo would surge at that pressure. You're compressors are possibly too big.

TJ

 

Knowing is half the battle. Get the gates sorted out. I don't think it's a surge issue either.