Hey guys,

Got my MBC in the mail today. I installed it correctly, but here's the thing. It spikes to 8-9 psi which I would of guessed anyways, and then goes down to 7 psi which is where I want it to be at. However, once it hits 7, it slowly creeps down to 4-5 psi and stays. That is where it was from the stock setting (GReddy TD04 w/ FMIC). I've checked everything for fitment and no luck. Still goes down. Not a fast drop, but a slow and steady drop from 7 to 4-5 psi. Any ideas about this? Is it just the controller being a piece of crap, and is something else wrong? Thanks guys!

 

anyone??

 

i don't know, but that kind of scares me about the MBC that i got from my friend, anyone have this problem before? help?

 

Let me ask you this, does it start to drop only at higher rpm? One possible explaination to that would be your turbo spooling to max boost at max torque but dropping off in efficiancy by the time your motor hits peak hp which would spin the compressor so fast that by the time you hit top rpm, it starts to loose boost efficiancy which would result in a 2-3 lb los of boost.

 

what is your set up and what kind of mbc do you have?

 

did you experience this before you installed the boost controller?

 

I had the EXACT same thing with mine. I used a boostvalve.com MBC and it did the same thing. Spike to nine or ten, drop to 7 or so, then creep down to about 5. I never noticed it until I added the boostvalve... it ended up being that my intercooler (conquest ghttocooler) was leaking a little. It seemed like the boostvalve amplified the leak enough that it was more noticable...

The only thing I could guess was that it was always leaking, but the turbo could make up for it when it only had to pump 5lbs. When I tried to get 7-8lbs, the turbo couldn't do it at higher rpms and slowly bled back down to 5 because it was spinning like hell. I fixed the intercooler leak and it hasn't done it since.

If it helps, I couldn't tell there was a leak on my own. I had checked several times and couldn't find it without load on the motor. I finally found the leak when the patch (remember, this is a ghetto intercooler) finally popped off. If the patch hadn't come off, I would have never found that leak.

 

Where are you running the pressure off of? I'm guessing the turbo compressor housing?

To get boost to hold, try running it off the intake manifold.

 

i just bought a Profec B and no problems with it.

I also found a cut in one of the house couplings so thats where my leak was. Anyone want a MBC?