MBC question

Jamah

New member
Hi, I searched on the forum but found nothing that could help me. The thing is that I bought a mbc on ebay and have to clue where the "?" marked hose would go. I tried to draw it on paint and here's what it looks like :lol:
thanks for u help
 

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Gary

Moderator
What is that thing on the upper right corner? (where blue lines are connected to)
Intake manifold?
 

Gary

Moderator
Indeed.
Normally, ball & spring MBC comes in one piece with 2 ports.
You connect the port on the ball side to the compressor.
And the other port to the wastegate actuator.
Then you disconnect the TVSV and cap it.
Can you like us to the auction?
 

Gurr

New member
To hook this up, take vacuum hosing from the compressor to the bottom barb fitting, then the top barb fitting to the wastegate actuator. The T piece doesn't need to be used.
 

Jamah

New member
are you sure because before blowing up my other 3s i hooked it up like this and i kept hiting the fuel cut.....?
 

Jamah

New member
pretty strange since they have tons of this kind on ebay :doh:
but the thing is that the spring and ball thing are in the T piece so i have to use it .... :shrug:
 

pepper

New member
Some kind of two-stage controller? The ball and spring set an initial boost level and the other part is a bleed unit to allow for further boost?
 

alanip

New member
i got the same problem ,can any one help us out ?
i have ask some people and they tell me the exhaust hose is no need to conect to anything, but when i tey this set up my boost is keep going up non stop
 

GT4RC

New member
Any chance it is the alternative to drilling this hole to prevent signal lock?
mbc-close.jpg


bit of a shot in the dark on my part though, as the link to the auction is down now and I can't see what you have. :shrug:
 

Gary

Moderator
From the instruction manual, this looks like 2-stage boost controller.
The ball&spring piece (T-piece) set the initial boost and the in-cabin bleed valve increases boost level.
If this is so, the exhaust hose doesn't have to connect to anything.

Try tighten the bleeder piece and see if your boost still creeps up.
If it still creeps up, you are having a problem with the ball & spring piece.
The spring is either too stiff or the ball get stuck and doesn't let any air passes through.
Using air compressor, try applying air pressure to that input port.
It should start opening and lets air through at 7 psi or whatever initial setting of that boost controller.
 

Gary

Moderator
Another solution, throw that POS away and get a basic $10 ball & spring MBC.
People have been using that for years without any problem (except few spikes now and then)
 

GT4RC

New member
Gary":1o6qri53 said:
Another solution, throw that POS away and get a basic $10 ball & spring MBC.
People have been using that for years without any problem (except few spikes now and then)
yeah, i built 2 of them and it cost me a total of 22 bucks. most of the places i got my parts from gave me what i needed for free.
 
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