Well, I finally got my 765 injectors in and I tried to turn the boost up and it only goes up to 15psi. I am running a 20g and Hallman pro MBC. I have the MBC turned all the way open and I only hit 15psi. What do I need to do to get it up to 20psi?

I am probably doing something stupid here.

Make sure your BOV is not venting. And check that your wastgate is not already partially open by some falut of some sort (bent rod mounting flange assuming that the 20g is internally gated). Give the MBC a one over look for any obvious problems like lack of a spring or ball ect. And when you say "open" do you mean that the adjusting screw is down applying pressure to the spring??

What do you mean my BOV is not venting? I hope your not meaning I need to recuirc it.

My turbo is internally gated and the rod going to the gate is not bent and is fine.

The MBC is turned on open the whole way and yes it has the spring and ball in it.

So I have no idea why its only boosting 15. Makes no sense to me.

Originally posted by Aggression
What do you mean my BOV is not venting? I hope your not meaning I need to recuirc it. My turbo is internally gated and the rod going to the gate is not bent and is fine. The MBC is turned on open the whole way and yes it has the spring and ball in it. So I have no idea why its only boosting 15. Makes no sense to me.

If its open all the way then the MBC is doing nothing and the 20G is opening at its preset 15psi. Try turning the MBC the other direction to increase the pressure of the ball and spring, therefore increasing the pressure before it opens.

Originally posted by djtrickee

Originally posted by Aggression What do you mean my BOV is not venting? I hope your not meaning I need to recuirc it. My turbo is internally gated and the rod going to the gate is not bent and is fine. The MBC is turned on open the whole way and yes it has the spring and ball in it. So I have no idea why its only boosting 15. Makes no sense to me.

If its open all the way then the MBC is doing nothing and the 20G is opening at its preset 15psi. Try turning the MBC the other direction to increase the pressure of the ball and spring, therefore increasing the pressure before it opens.

+1...increasing the tension on ball/spring, thus increasing amount of boost needed to open it :thumbsup

Well I am turning it the way the top says to increase the boost preasure. If I turn it the other way it lowers the boost preasure.

Seeing how when I just had it at 13psi, and turned it right it went up to 15psi I have a hard time believing I should turn it left which is reducing the boost to increase it.

I will turn the knob left then!

Maybe you have a bad boost controller :shrug

Originally posted by djtrickee
If its open all the way then the MBC is doing nothing and the 20G is opening at its preset 15psi.

The 20g comes with a internal 8psi wg unless you do the $75 upgrade which is the 15psi wg.

Originally posted by djtrickee
Try turning the MBC the other direction to increase the pressure of the ball and spring, therefore increasing the pressure before it opens.

If I turn it the other direction it decreases the boost level.

I just find it hard to believe my Hallman MBC only increases the boost 7psi above what the wg is preset at.

I wouldn't think I had a leak...I did notice that the MBC leaks a lot out of the side of the valve that runs to the actual wg which I thought was to bleed off the pressure.

Not really sure what to do at this point.

Remove the vac line from thewastegate and lightly boost it. If it shoots past 15psilet off. The wastegate is good and your IC piping is holding pressure. The MBC could be the issue.

If you still cant boost past 15psi then you have an issue with leaking pipes or wastegate remaining closed.

Terry

I will give that a try...I also just got off the phone with Mark at Hallman and he said the spring in my controller might not be stiff enough for some reason. He is sending me the stiffest spring he has in the mail right now just in case.