Ive got a diy mbc that i bought off of ebay. It has a bleed port on it, which I believe all mbc's do and I can see why they would need it. The problem is that by just blowing through it the air comes out the other end just fine, but when i cover the other end the air just automatically flows out the bleed port. It seems to me like this would cause the wastegate actuator to never open the wg. I am off here? I hope so.
Here is a link to one that is like the one I bought. http://cgi.ebay.com/ebaymotors/ws/eB...&category=6764

 

the end pointing right goes to the turbo and the end facing down goes to the wastegate. there is no bleeding.

 

^

 

There has to be a bleed port to let the pressure get out from the wg, or it would think you are at whatever was the highest boost you had recently.

 

I found this description of the bleed port.

7. Carefully drill a small (1/32") hole into the body of the MBC as shown by the arrow in the cut away aside. With the bleeder hole in this position the same end result is achieved as with the coupling, but it reduces the number of parts required to fabricate and install the MBC.

The bleeder hole is not large enough to affect the signal to the Waste Gate but it is necessary to gently vent off excess vacuum or pressure in the line which causes a type of signal lock. If the hole wasn't put in, the controller would have difficulty controlling boost above about 15 pounds.

Heres the link to the writeup on how to make the mbc's. I know there are a lot of these, but this one is a really good one. http://www.geocities.com/chmwatson/FAQs/mbc.html

 

just hook it up...

 

Good call I just worry too much