MBC Problem

[TsiTalon90]

Ok I have a hallman bc and supporting mods 255 fuel pump 3in intakew/ hks filter. 3in apexi all the way back. Blitz bov, and I have it set to the most least amount of boost it can go. My autometer guage goes to 15lbs but then at higher rpm it will creep to 17 and thats when it'll hit fuel cut. My question is why can't I lower the boost on this thing. I screwed around with it and and screwed in the knob a lil more and at about half throttle the boost will keep going to like 20 so i turn it back down to the best setting i can. Does this have anything to do with the spring stiff or hard so I car run like 14 and spike at 16?

Thanks




Tial Bov onthe way!

 

[TsiTalon90]

BUMP

 

[Enigma_Man]

Well, first make sure that your MBC is connected correctly. An incorrectly hooked up MBC will cause the boost to rise without stopping, until your turbo or motor gives out, whichever will happen first (and it will happen quickly).

To test this, connect the wastegate directly to the intake vacuum/pressure line, eliminate the MBC from the equation. You should see around 7 psi or so.

If you do not see ~7 psi, then you are running into boost creep. Your exhaust finds it easier to go through the turbo than through the wastegate. To fix this, you can get an upgraded and/or ported O2 sensor housing, and that will help out a ton.

-Jesse

 

[TsiTalon90]

Alrite thanks man