My friend with a turbo'd hatch has a problem and wondering if anyone could help. "to anyone who can help! my turbo'd civic is giving me a fit and may have been before i know its nothing major, i think it has to do with vaccum.runs fine. but when it reaches 5k rpm/16psi boost. it shuts car down like a fuel cut but its not. if you unhook blow off valve vaccum car will run fine but bov will open releasing pressure and only pull 11psi. im not a turbo guy so idk nothing about it. help would be great its running on boost by gear solenoid but its cutting at 16psi in every gear"

Any ideas?

 

Tune. Need way more info on the setup. Maybe your friend needs to get on directly instead of relaying info second hand.

 

sounds like it hitting fuel cut. could be caused by boost creeping or fluctuating boost just past fuel cut set by the ecu. mine used to do this in the winter running a internal wastegate. id creep just past 10psi (stock map sensor) id feel like it would buck and throw me into the dash. id have some one look over it. taking the vacuum off the BOV should not affect boost because its function is to release all the built pressure in the intake pipe. with it using a vacuum line it helps pull it open quicker to release it so you don't get any back feed through the pipe to cause compressor surge. tells us more about the setup is it internal or external wastegate? you definitely need to control ur boost or try turning it down a few pounds and see if it still does it. boost by gear im not too sure if ur running hondata and a solenoid or turboxs has a system out as well and others. if u cant you need some one that knows what their doing to fix your map and turn it down or fix the fuel cut if the motor is built and if its not u shouldn't be boosting to these pressures on a stock motor unless its a baby turbo. as said above u need a tune.