Hey guys. So I'll give it to you guys short and sweet. I'm boosting at around 13-14 psi idk. First when I put my MBC in I boosted at 30. Turned it down to about 15. Now I can't get it up or down. It's a new MBC. I have a hallman MBC. The tip straight across the knob is going to my bov that is t offed. And the bottom one is going to my waste gate. Turbo is closed off. Any help. Thanks

 

How did you achieve this? Check to make sure that the compressor nipple is in fact, sealed tightly. Sometimes, those little rubber block off nipples sold in the auto parts stores can rupture, slip off or otherwise lose pressure.

 

I used a black nipple from my local auto parts store. Everything seems to be fine.

 

Did the MBC come with its own vacuum lines? What I am getting at is that the factory vacuum lines have those internal restrictor pills. So, instead you want new 4mm hose. Dont reuse the factory boost/vacuum hose assembly, But, your MBC must have come with two new hoses, huh?

 

If you turn the MBC'S adjustment knob all the way in or all the way out, boost does not budge from 15 PSI? Is that right?

 

New lines everywhere. Should I run my input line from my turbo and my output to my wastegate? Or is this setup fine?

 

As you mention above, you can employ as your boost reference source either the compressor discharge tube(j-pipe) nipple, or "T" into the hose that runs from the IM to the DV. Either way. It's 6 of one, 1/2 dozen of the other.

 

BTW, what brand MBC is on there? Is it a stock diverter valve? Stock turbo?

 

The side port on your MBC, the one oriented at a 90* angle to the axial centerline of the adjustment knob's shaft gets routed to the nipple on the WGA. The other port directly opposite the adjustment knob, that is the port that is axially inline with the adjustment knob's center line at the opposite end of the MBC body from the adjustment knob, is the boost reference port. This gets connected to the boost reference source (j-pipe nipple, or DV "T"). Got it?

 

Hooked up exactly like this. Input from turbo to input of MBC. And input of wga going to the bottom nipple of the MBC. I did 10 pulls. 3 gear I did 8 psi. 5th gear I did 13 psi. I turned it up all the way and same thing nothing changed. All new lines. No pinches or holes. All sealed. What can be the problem? At one time the MBC worked fine. Now it hasn't been the Same. I've owned it for about a month. Any ideas.? I need help. I can't figure it out.

 

Bump Amyone you guys. Any help would be great.

 

Sorry, I am travelling so I dont always have server connectivity.

 

Where are you located? Are you in souhern california? If you were in SF area I could solve the issue for you. I am in Hayward.

 

I live in YC,Ca. Thats about 2 hours away. I can Txt you a pic of how I have it hooked up. 530-923-3841 is my number. Btw I have turbosmart bov and a Hallman MBC

 

well, 13 psi is wastegate boost, it seems that the Knob could be adjusted the wrong way or you may be missing the spring inside the boost controller that hold the ball inside of it from moving.