if you don't have an aftermarket BOV, i'd recommend it. i did some boost tuning and kept getting a weird taper until i went with an MR BOV and now my car holds boost like a champ.

 

^^^^ That's what I wanted to know. I am having some of the same problems as mentioned above. Before an accident 21 PSI in all gears. after accident (new Buschur FMIC) boost is all screwey. Ordering MR BOV today.

 

I bet your MBC's boost source is coming off the compressor. Cap that off and get your boost source from the BOV vaccuum line instead, more consistant boost levels. I've tried both and got the same thing as you when I was running my MBC off the compressor nipple.

 

I have never seen 19psi in first or second gear in my car stock or with the MBC I run. So some of you see 19 in first and then the same level thru the other four gears?

 

With the stock FMIC the boost would jump to 21PSI in all the gears with a MBC that was connected to the turbo/stock Lower I/C pipe.

Now that I have the Buschuer Deluxe FMIC I had to move the MBC to the BOV line. But no more 21PSI in 1st or 2nd. Well, first gear revs up so fast it hard to tell if you hit 21PSI but 2nd is like 15PSI. Third gear is trickey, it will Jump to 21PSI and I have to modulate it with the gas pedal to keep it right around 21PSI. 4th is almost the same way, and 5th it has a hard time reaching 21PSI I usually have to slow down before it reaches 21PSI.

So it sounds like I am crazy!!! I'm not sure what to do. Get a new MBC? some one tell me the right way to set a MBC. Do you set it in 5th or3rd? I checked all my connections I am almost positive no boost leak. I have a MR BOV on the way. could it be the wastegate leaking?

Or is all of this normal?
Thanks

 

my car is stock in terms of boost control(05 model) and in 1st and 2nd I hit 1.4bar and in 3rd and 4th I hit about 1.5 or 1.6bar(if its cold out)
I really need a MBC