MBC install, won't boost past 13psi.

[djwimbo]

I installed a MBC today, and I can't boost past ~13psi or so. When my N75 was being used I could hit 16-17psi @ the manifold.

To the best of my knowledge I have it installed correctly.

Does it make a difference what type of MBC I have? A guy at work said he'd sell me this one for pocket change basically. It's the Forge valve that's on ECS for $35, IIRC it's considered a bleed valve. Would the Ball and seat style work better?

I installed it like it says to, the bottom leg goes back into the TIP like the N75 did, and the opposing legs are connected to the compressor nipple and the wastegate actuator.
Did I do something wrong? Would it make a difference if I used a boost reference off the DV line, so it sees manifold pressure instead of compressor housing pressure?

Looks like this.

[djwimbo]

anybody?

[Militant-Grunt]

Are you opening or closing the valve to increase boost. Because you're supposed to be closing it to increase boost.

[2001A4QUATTRO]

You have to use a ball spring style to replace the N75 or to go inline and limit spikes. To raise boost with a bleeder valve you need to put N75 wastegate pressure on one side, and the other side to the wastegate. The bottom then bleeds the pressure to atmosphere ( or turbo intake pipe )

[djwimbo]

that sounds overly complicated. I'll have to find a ball/spring setup.

EDIT: For humor's sake I tried intentionally installing it incorrectly. I thought about it and the point of the boost controller is to meter the amount of vac/boost supplied to the wastegate actuator right? So I tried it with the metered leg (bottomleg) installed as the output to the wastegate actuator. Now I can hit 15psi, but it still doesn't hold it any better than it did before.

Why does my buddy's MBC on his Jetta let him hold boost a lot longer than I can? Essentially they're the same turbo (K03s), is it b/c he's probably using a Ball and spring?

[djwimbo]

put N75 wastegate pressure on one side, and the other side to the wastegate. The bottom then bleeds the pressure to atmosphere

Sweet, I did just that and it works. Thanks for the advice. I'm not 100% green on the MBC stuff now.

N75 alone I'd spike 17psi on a good day and taper down to ~7psi @ redline.
N75 + MBC I'm hitting 19psi(manifold) and tapers to ~10psi @ redline. Now is holds 14-15psi a lot longer than it used to.