OK well my setup is in my signature. it seems that once i fix one thing something else breaks! i just fixed my bov problem and now im only boosting 5 psi. i dont get what is going on. before i was 7 strong now im at 5.... this is starting to piss me off. i just started it up this afternoon after driving it all morning no problems. well it get in and start it up and im only getting 5psi instead of 7 like i was before. pressure checked it and there are no leaks its holding the pressure just fine. so im guessing its something to do with my wastegate or turbo. im running open down pipe right now so it cant be to much backpressure. If anything i should be spiking because the open exaust.

Is your BOV running off of the brake booster line?

That's what mine did when I hooked up my BOV to the wrong side of the brake booster line. The brake booster vacuum line has a check valve to always hold vacuum. If you hook your BOV on the booster side of the line, it always sees vacuum, thus stays open all the time. All the boost you build up goes straight out the BOV. No matter how fast the turbo spins, it can't build pressure.

If your BOV isn't on the brake booster, it might just be stuck open. Or it may be something else totally, but given you were just messing with the BOV, that's where I've got my money.

My bov is off my throttle bodies and it worked fine with 7 psi then thisafternoon it was at 5.... i dont know what happend! i dont think its being pushed open or anything since its a ssqv.. its supposed to help keep the bov closed.

My bov is off my throttle bodies and it worked fine with 7 psi then thisafternoon it was at 5.... i dont know what happend! i dont think its being pushed open or anything since its a ssqv.. its supposed to help keep the bov closed.

not the one underneath the throttle body right the one on the side?

check the wastegate itself--sometime the spring sticks

Yea my first thought was it was the wastegate bleeding off boost.

Yea my first thought was it was the wastegate bleeding off boost.

wouldnt that cause it to spike boost *** not lower it?

not the one underneath the throttle body right the one on the side?


no the bov it sonnected by itself to a dedicated line.

ok well i tested my pipes today i couldnt find any leaks... the air slowly just trickled out of my valve cover hoses. it held 20 pis just fine so it cant be a boost leak what is the stock wastegate set at? 7psi? thats what i was boosting before.

wouldnt that cause it to spike boost *** not lower it?

You need to go back to turbo school. A wastegate stuck open = less exhaust to spin the turbo. Less spinning = less boost.

You need to go back to turbo school. A wastegate stuck open = less exhaust to spin the turbo. Less spinning = less boost.


oh sorry sorry sorry lol i thought they meant the diaphram in the wastegate having a hole in it and it bleeding off boost lol. I get you now lol.

Ok well i put on my MBC and its going strong at 9 psi. Anyone know what gtirs come with stock? im pretty sure that its 9psi but i could be wrong.

Yup, the stock boost setting for the GTIR is 9psi. Also, how did you end up fixing your bov problem?

i had to adjust all my throttle bodies for the same vacuum then i gave the bov a dedicated line for just the bov off the throttle bodies. blows off perfectly now.

Are you running the stock turbo and WG? If so it is adjustable pressure wise. The WG actuator is threaded and can be tensioned or loosened to raise or lower boost. Is it loose?

yes im running the stock wg and turbo. ill have to take a look at that wastegate acutator i guess. maybe that might be the problem!

what kind of air filter do you have on it?

Funny you ask i just put a new one on yesterday. Its a HKS mushroom filter thing.

i thought stock boost for a t28 was 8psi?

no on the gtir its 9 psi. i cross referenced the nissan manuals to be sure.

crap i think i was running 8psi and it was stock, although my boost gauge is off, thanks for the info