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Discussion Starter · #1 ·
how and where do i install the MBC? i want to know before i order it this week...should i also install a boost gauge with it? i mean, it would be logical to see if the boost went up or not...where do u guys suggest i buy these? and which size would fit my analog clock or the headlight switch areas?
 
G

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The MBC replaces the APC solenoid, and yes - buy a boost gauge otherwise you'll have absolutely no idea what's happening to the engine and you know what happens when there's too much boost in there!

Abbott racing and Partsforsaabs both do MBC's to suit the trionic system.

Gauge wise you need a 52mm to fit in to the clock or headlight switch area. Marrk has put his in the clock space so have a chat with him on the process.

Most boostgauges are 52mm (2 inch) but check before buying. Partsforsaabs, E.l.k.parts (sorry admin) and loads of other places do boost gauges.

If you want a really spanky electronic one (noiseless), do a google search on 'Defi'.

:D
 

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I guess on an LPT there is a point for the APC "R"eturn hose to fix to that's just blocked off. Anyone know?
 
G

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Yep, there is mate. It's on the air intake hose closer to the turbo than on the FPT's.

But be VERY careful when attaching a hose as the plastic is very brittle and it can easily snap off......as mine did.....which annoyed me......and took a bl**dy ages to fix!!!!
Other than that, same as the FPT. W to wastegate, C to turbo body and R to air intake.
 
G

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You don't need the APC solenoid. The MBC is a direct replacement for it.

On the MBC there are three inlets/outlets which you attach hoses to, W to wastegate, C to turbo body and R to air intake.

Then set the MBC up using a boost gauge, gently at first to be on the safe side, then increase the pressure until you have a boost level you're satisfied with.
 

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I would HIGHLY suggest a Ball and Spring Style MBC over a basic bleed valve. The Forge is a bleed valve. I don't know about the PFS but I would suspect that it is also a bleed.

Bleed valves were simply replaced by the superior working of a ball and spring style MBC.

A bleed style MBC will regulate air coming through the MBC so it does have the ability to increase boost pressure but your spool up time is not dramatically increased like that of a Gaited(ball and spring) mbc. Bleed valves also have overshoot problems(as do ball and spring styles) but with bleed valves, you have to compensate more being that a set amount of air can only pass through a set amount of space. With the ball and spring style, the signal is gaited for moments longer allowing faster spool up and when the ball cracks off its seat, there is full pressure to the WGA to help with opening the WG faster. The baal/spring style has its problems reacting too late but the +A can deal with that. A +A will not work with a bleed since the inherant nature of the bleed valve is that the WGA is always seeing pressure so adding a +A would just open the WGA too soon.

There are a lot of options out there for ball and spring style MBC's, do a search. There are millions. Some are good and some bad but still better than bleed valves.

MBC Setup:

Turbo hose barb to MBC inlet
MBC outlet to WGA hose barb
 

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Discussion Starter · #12 ·
im about to order the MBC from partsforsaabs.com it says....Not recommended for Trionic ECU equipped Saabs.

i have the Trionic 5....will this still work?


and can someone plz draw me a diagram of how to install the MBC with a boost gauge?
 

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If you have a LPT (which you do, if you don't have a boost gauge) don't you need some kind of ECU upgrade, to avoid the fuel cut off (which I don't remember where is, but I'm pretty sure it's much lower than the one on FPT cars)?
 
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