[dubburke]

I tried a search but it still never answered my questions....
1. The MBC is a cheap way of increasing boost, but the at the expense of APC control, I thought that if boost was increased fuelling would also need to be increased to stop the engine running lean (BAD!) so if the APC isnt in control anymore, how does the engine get extra fuel?
2. Apart from the bother with the weather/temp causing a possibility of the fuel cut off, is there any other negatives in installing one?

 

[stromer]

The car runs pretty rich to begin with, and the increase in psi is not too much for the engine to handle. Many people have had these devises installed for years. Mine has been on for 20k miles without a hitch.

 

[dubburke]

Just interested but roughly what gain would the MBC give if fitted to a standard NG900T? And what kind of gain on top would the k&N combined with the free mods such as turbo silencer removal 3 inch intake and removing the lip restriction on the throttle body inlet pipe?

 

[ricot83]

non of those mods will give u any noticeable gain. the mbc+a will give about 15.5 psi so whatever that equates to power on a t25 turbo.. which isnt much

 

[dubburke]

non of those mods will give u any noticeable gain. the mbc+a will give about 15.5 psi so whatever that equates to power on a t25 turbo.. which isnt much

dissapointed, i must have read too much into Erics site;oops:

 

[bkrell]

Hey, take that back about the mbc!:cheesy: Now, it's not going to turn your car into a ferrari, but it does offer a nice little performance increase for the dough. It rids you of the lowered boost in the first 2 gears and redistributes torque a bit lower for a little more "oomph."

Ricot's jealous b/c he has a T7.:cheesy:

As for it's safety, it's fine. The apc is not the only way that your ecu prevents leaning. It will also advance/retard the timing so that you will not build too much compression. That is not affected by disconnecting the apc.

 

[dubburke]

Hey, take that back about the mbc!:cheesy: Now, it's not going to turn your car into a ferrari, but it does offer a nice little performance increase for the dough. It rids you of the lowered boost in the first 2 gears and redistributes torque a bit lower for a little more "oomph."

Ricot's jealous b/c he has a T7.:cheesy:

As for it's safety, it's fine. The apc is not the only way that your ecu prevents leaning. It will also advance/retard the timing so that you will not build too much compression. That is not affected by disconnecting the apc.

Take that T7 :nono;
There is light at the end of the MBC then!!!
Will the MBC give sustained boost of 15ish if thats how its set?

 

[Ice Man]

Make sure you get the MBC+A! It's so worth the extra $50 bucks. MPPerfromace has them http://www.mpperformance.com/catalog/product_info.php?cPath=3_24&products_id=44 And do those free mods + K&N, also save up for a used viggen IC for the future.

Have fun!

 

[ricot83]

BK u forget i use an smbc on my car for a similar use.. i am not jealous :cheesy:

 

[bkrell]

I know you aren't ricot, LOL, but you also haven't felt the thrill of going from 9 psi of limited boost to 15 with a small investment. BTW, I was one of Jeff's first customers and got mine MUCH cheaper. So it was really good for me.


Yes, the MBC+A will allow you to sustain boost at 15.5. Really the throttle body tap is the key to that, but the pressure regulator is great for dealing w/ avoiding the fuel cut in cold weather while still staying at 15.5.

 

[Shaft]

I know you aren't ricot, LOL, but you also haven't felt the thrill of going from 9 psi of limited boost to 15 with a small investment. BTW, I was one of Jeff's first customers and got mine MUCH cheaper. So it was really good for me.


Yes, the MBC+A will allow you to sustain boost at 15.5. Really the throttle body tap is the key to that, but the pressure regulator is great for dealing w/ avoiding the fuel cut in cold weather while still staying at 15.5.

And I 2nd his post. :cheesy:

 

[ricot83]

I know you aren't ricot, LOL, but you also haven't felt the thrill of going from 9 psi of limited boost to 15 with a small investment. BTW, I was one of Jeff's first customers and got mine MUCH cheaper. So it was really good for me.

you are right u r right


hahahahha but i have felt the difference of going from 7 psi to 14psi hahahahahaah :lol: :cheesy:

it is awesome...

 

[bkrell]

Oh well...

 

[avixcore]

Does the SMBC change boost in T7 cars..peak wise? Or at least get rid of that limit in 1st and 2nd.

 

[ricot83]

its real complicated AVI with much time invested i have gotten the car to run consistently with an extra 3-4 psi.. any more than that and it wont boost consistent for long since there is a limp mode

 

[WyldSaabMan]

rico i also remember you saying something about your wastegate not opening as far as it could be, because you had to bend the actuator rod or somthing to get it to work with the new exhuast side...could this also have something to do with your raised boost levels

 

[DFroelich]

A friend installed a MBC and cut down the boost creeping to nothing. He just trimmed the in and out lines as short as he could to limit the amount of pressure flucuation inside the tubes.

By spending the extra cash for the MBC+A, what other benefits would there be? I imagine his MBC will need adjustment once winter comes, but is that all you get for the extra $50?

BTW dubburke, putting in the MBC at 15psi was enough blow his clutch that week. It was the original with 60k.

 

[bkrell]

Well, the benefit is you get a good MBC, first of all. I tried some eBay ones before and they worked like crap. On the +A, you don't have to tweak it as much as a regular mbc, either. With the apr, the extra air going thru is just enough to open the wastegate faster so you don't overshoot.

I'll just say I recommend it and invite you to search the forums for more on it. Do an advanced search under mbc+A and put SPATL (use the right case) in the user name section. Look for the older posts.

 

[SPATL]

A friend installed a MBC and cut down the boost creeping to nothing. He just trimmed the in and out lines as short as he could to limit the amount of pressure flucuation inside the tubes.

By spending the extra cash for the MBC+A, what other benefits would there be? I imagine his MBC will need adjustment once winter comes, but is that all you get for the extra $50?

BTW dubburke, putting in the MBC at 15psi was enough blow his clutch that week. It was the original with 60k.

And if he had put in a modified ECU, that would have happened as well. Performance doesn't come cheap.

The other benefit is that it effectively allows you to move your boost tap downstrean of the IC which in short allows you to sustain boost for longer periods of time without droop. This is due to the pressure drops across the IC and allows the MBC to regulate peak boost closer to what the ECU sees via the MAP sensor. Much less fiddling when the temps flux as well.

 

[bkrell]

BTW dubburke, putting in the MBC at 15psi was enough blow his clutch that week. It was the original with 60k.

Hah! I just noticed this part. NOOO WAY was the MBC the problem. Now, maybe his heavy foot as a result of the MBC, but not the MBC! He must have either had a clutch already dying or he spent the whole week doing nonstop redline clutch drops.

I installed mine at oh, 135,000 miles or so and now at 185,000 I haven't had the slightest bit of clutch slippage.