I can't get past 12 psi (i've posted two other threads, but normally people don't like to read the whole thread)
I have a newly installed wastegate, manifold, o2 housing, and mbc.
here's what I have tried:

-Checked vaccum lines and replaced three lines
- Shortened the wastegate arm pretty much all the way
- mbc has been verified and is hooked up correctly
- Took the line off the wastegate and still can't get past 12 psi
-Turned mbc all the way up (hallman pro)

Now here's what I do have: I have a pretty good size exhaust leak where the manifold meets the hotside (one of the studs broke off) Now, no one has been able to verify for me if that could be the problem. I think it might have a little to do with it just because I don't think its able to build pressure and open the flapper enough to correctly operate the wastegate. But i'm no expert. Any ideas?

 

Quote:

Originally Posted by subrwho

I can't get past 12 psi (i've posted two other threads, but normally people don't like to read the whole thread)

Look, 1st thing is you absolutely MUST FIX the nasty leak between the turbo and the exhaust manifold, because although it is not directly related to your low boost problem, any pre-turbo exhaust leak plays havoc on air/fuel ratios and O2 readings leading to huge knock counts and massive timing and fuel over corrections by the ECU.

Did you hook up the side port on your MBC to the nipple on your WGA? Did you hook up the bottom port(port diametrically opposed to knob) on your MBC to your boost reference source(either the nipple on the turbo's compressor housing discharge tube or a "T" into the DV/inlet manifold hose)? Did you completely remove the original factory vaccuum/boost hose assembly and cap off all unused vacuum ports?

If your problem is not a malfuctioning MBC or faulty vacuum hose routing, then I would look at your new Forge WGA's threaded rod being to long in which case you'll need to trim about 3/8" off the threaded end of the actuator rod. Be prudent though as you don't want to chop too much off either.

In some applications the Forge WGA's threaded rod as delivered is too long causing the threaded tip of the rod to bottom out inside the turnbuckle end preventing sufficient adjustment.

 

yeah it sounds like you may have reversed the MBC install... yeah that major exhaust leak will totally throw off the ecu and also u wont be boosting much either.

my advise is troubleshoot one obvious thing before tackling another.