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I've just got an MBC (ball and spring) to go on my CSE 2.3T. Trouble is, I've never used an MBC before so I'm a bit clueless.

Is there a good idiot-proof procedure?

My guess is that I need to set it up so that I can't hit the fuel cut-out no matter what I do.

Is there a direct correlation with the non-Aero turbos between the amount of boost and the RPM? It seems to me that no matter how I adjust the MBC, the peak boost above about 3000RPM is pretty much the same - I am wondering if this is a limitation of the turbo. In other words, do I need to concentrate on adjusting the boost at low revs?
 

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You'll want to set the boost in 4th or 5th gear. Set it so that the initial boost spike will not bring on a fuel cut. This will give you the ability to put the gas pedal to the floor in any gear at any rpm without fuel cuts.

A fuel cut, if you have never experienced it before, might startle you. Start the MBC at a low setting and then go out on the highway and give it full throttle, from low rpms, in 4th ot 5th gear. If there are no fuel cuts, you can raise the boost more. Keep going until you start getting fuel cuts, then back off just a bit. This will be the max boost you can run without getting the fuel cut.

Also, take note that you might have to readjust, time-to-time, as the weather changes. I remember having to adjust down a bit towards the winter and bringing it back up again as the temps rose again.
 

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hi people sorry to drag up an old topic but is the fuel cut off system fail safe? is it still possible for the engine to run lean before fuel cut off? I have just bought an mbc but i am very reluctent to adjust without checking air fuel mixture and boost with correct gauges maybe i will be better off getting it done pro? as i dont have the correct tools to test
 

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The fuel cutoff is a last resort, and the engine could be running lean by then. However, as long as you don't have a remapped ECU with an uprated fuel cutoff then you will probably be OK. I can't remember what the fuel cutoff point on an NG900 turbo is. Use a calibrated boost gauge and don't exceed 1 bar max and you'll probably be OK.
 

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thanks for the info.i bought a boost gauge today but the fitting instructions are poor i am thinking of installing it between the manifold and map sensor but im not sure,will this affect the map sensor operation? i am new to any mods on a turbo there is probably an easy way to fit it,can anybody advise me on the best place to fit it and to route the vac hose? any info would be much appreciated thanks.
 

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You can tee it into any hose BUT the MAP sensor one. However, you may find there is a spare nipple on the manifold that you can attach it to.

Alternatively, assuming your car already has the stock boost gauge, if you want to permantenly fix your graduated one, then it's easiest to find the hose behind the dash as this avoids having to run a tube through the bulkhead.
 

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Thanks i will have a look for a spare nipple on the manifold if not can i tee it off fpr hose or the by pass hose? i read somewhere that i can run the hose through a blanking plug in the foot well? how much work is required to use the existing hose i am assuming it requires dash display removal? i havnt had a look yet because it is lashing down with rain
 

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i have had a look and i have decided to tap into the by pass valve hose and to run the hose through the bulk head above the brake pedal i hope this is ok guess i will find out soon as long as it dont start raining again! (i love this weather!!)
 
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