MBC not working

[taberj47]

well heres the pic i went from a nipple on the pipe goign to the sidemount and then connected it to the wastegate and my boost is spiking to like 15psi or more scared me a bit so this mbc is brand new and im pretty sure i have it setup right any suggestions to what else i can do or if it is wrong let me know?

sorry forgot to include the horizontal vaccum is going to the j pipe and the other to the WG.

[ExtremeTurboSystems]

have you tried screwing the bolt all the way in and out. You want to start with it out (smallest amount of pressure on the spring). Then screw it in slowly. As you put more pressure on the spring (inlet) it will take more pressure to push past the ball and spring and let the wastegate see the boost pressure.

[Mischif]

Take it off and blow through the hose and keep loosening the adjusting bolt until you can easily blow it open. Then put it back on and start adjusting from there.

[c2ypt1c]

Have you tried running straight wg pressure?

[LiquidX]

16g turbos are notorious for boost creep. Does the 15psi spike drop down to what you have it set to or does it continue to rise?

[ChrisTheBuilder]

Spring could also be hanging on the threads, happened to me.

[taberj47]

it will just keep climbing so now i dont even get on it for it to spool up afraid of disaster but ill try the screw it all the way in and out n where can i pull vaccum off of then bc i know of the 1g bov is bad from what im hearing.

[LiquidX]

Originally Posted by dsm94

I wouldnt run off wg pressure. Too many people blow there motors doing that.

You can only go as low as the waste gate pressure. A boost controller allows you to INCREASE boost psi over wastegate spring pressure.

It's safer to run wastegate pressure.


As mentioned boost creep is common and pretty much requires porting the turbine housing wastegate outlet or running a restrictive exhaust system.

[c2ypt1c]

Originally Posted by dsm94

i wouldnt run off wg pressure. Too many people blow there motors doing that.

At this point the OP needs to clarify what he means by "spiking." To me, it sounds like the wastegate is not opening, boost is "spiking" up quickly. If he runs wastegate pressure (~10psi) and verifies that it is holding steady, then we can rule out the wastegate not opening properly and pin it on the mbc. Of course if it's creeping (what liquid suspects), then that is a different story...

OP, to run wastegate pressure run a vacuum line from the turbo compressor (or jpipe) straight to the wastegate actuator. This will essentially bypass your mbc altogether.

[taberj47]

alright found out my problem the spring was hanging on a thread not allowing the spring to move so its works now lol anyone can kinda give direction on what to do like modification wise i wanna run 16lbs i caught the bug.