in cabin MBC t fitting

[KKneipper]

I bought a knockoff of the TurboSmart in cabin MBC, without wanting to actually put it in the cabin (it was cheaper and i thought i could make it work). So, hooking up the MBC without the t-fitting that came with it didn't add any boost no matter how much i screwed with it, and the BISS screw. So i decided to use the t-fitting and follow the instructions which stated that i needed to vent the "exhaust" on the MBC to atmosphere.....

That didn't make any sense to me, but i did it, and got what seemed to be unlimited boost. it wouldn't stop spooling until i let off the gas. I didn't want that (obviously), so I started looking at the t-fitting and took it apart. it has a ball and spring, but i don't believe it was set up right.

As you can see in the picture i tried to draw, that there is a divider in the middle of the t-fitting. The port that goes to the MBC is on the same side of the divider as the input from the pressure source on my compressor housing.

A.
So if the Ball is up against the divider, then the pressure would only increase and there would be no way to let pressure to get to the wastegate.

OR

B.
If the ball is against the port leading in from the pressure source, then pressure would be able to get to the wastegate, and (depending on the MBC setting) it would still limit (in the good way) pressure from reaching the wastegate.

The only problem i see is that if i blow into the input port with it set up as "B" i can't get the ball to budge, and don't want blow my turbo up. But I'm sure that i can't generate 16 psi or more with lung power.

OR

C.
I could remove the spring and ball and not have to worry about it.

ANY IDEAS?

 

[KKneipper]

wow... 24 hours and not one piece of feedback? seems like everyone is stumped like me. i've done my research and can't quite figure it out. mainly because the only instructions i've found are for the actual TurboSmart one, which doesn't have a divider in the middle of the t-fitting.

in those instructions, the t-fitting internals are set up as "B." but i don't know if the divider makes a difference, and don't want to risk massive compressor surge to find out.

 

[knochgoon24]

It looks like the MBC must be a bleeder type. That ball and spring act like a check valve so you don't suck anything in through the MBC.


Hook it up like A. You'll want the top port to go the the MBC, the right port to go to the wastegate, and the left port to go to your pressure source. To adjust the boost, you'll have to turn the knob on the MBC to it bleeds off pressure faster or slower. The more airflow through the MBC, the more boost you'll get.

It's the same type of setup as the car uses stock, but it controls that valve electronically by pulsing it open and closed.

 

[KKneipper]

So I'm guessing that I was right when I figured that the arrow pointing towards the wastegate was backwards.

And yes, the MBC is a bleeder type. If I would've realized that it was going to be this much of a pain to get it to work right, I would have just spent the extra 20 bucks on a JoeP. I'll hook it up like that and let you know how it goes.

Thanks.

 

[KKneipper]

I got the MBC hooked up yesterday, set up as "A", but with the arrow pointing to the compression chamber instead of the wastegate. So far, it's good. Real good. i got it set so it surges to 19 psi, then settles at 16. This car is pretty quick now, even being an auto it still hangs with my buddy's 97 gst stick off the line. I'm glad that the MBC helped get rid of the first gear lag too.

 

[Marty Staggs]

When you buy counterfeit product, you are gambling.

No quality assurance, no product support, and not nearly the same results.