So I recently went from a 2.9 pulley to a 2.7 pulley, and gained no boost or airflow at all. Max reading of 16 lbs of boost with a 3" catless exhaust and no headwork (or anything else that would mess with airflow).

2.9:


2.7:


The tune has a boost limit of 19 PSI, and I just replaced the hoses and put zip ties on them to make sure they're not leaking from the edges. After a bit of forum diving it sounds like it might be the boost bypass valve. The descriptions on the threads were kinda vague, can anyone explain how to adjust it properly?

 

i was gonna guess belt slip but if its the exact same, ty this, pull off your boot controller and see where it takes you

 

You mean do the boost bypass mod to see if that takes care of it? That was my next step.

 

pm sent.

 

Hmm, from the sounds of it I'm leaning towards actuator/solenoid now. I'll back out the little black spacer screw a bit to see if that lets it hit full boost.

Failing that, boost bypass mod time.

 

Back the little allen screw out until you feel the bypass valve start to stick when opening it by hand. Then adjust the allen screw in until you cant feel any sticking or resistance when opening the bypass . The sticking point your feeling for is the bypass valve binding when it's gone past full close in the opposite direction . .... IF that makes any sense to you lol.

Thats about the only way to do it without taking the blower off to visibly see the bypass.

 

I know exactly what you mean, it wasn't binding at all after I backed out the screw today so I'm hoping it just was not closing completely. Thanks for the info fellas.

 

What screw are you guys talking about and what is this boost bypass mod? I have Stage 2 and I never see anything over 15 so am I having an issue here?