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So I have my mbc+a on all the way. But I am still not hitting fuel cut. In 2nd gear i can make it a tad into the red, then it fades back down into yellow. In 3rd It will go a tad under halfway into red, then dip back down to end of yellow, almost in red. Is it normal for it to spool up and boost hard then die out a little bit when you have it floored? Here are the things I have checked,

-IC Hoses
-Vac Lines
- Taken hose off of waste gate
-hose between tb and iac

What am I overlooking here? I would like to get max performance out of my mbc+a before I decide to buy a 3" dp or anyhting else for that matter.
 

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Obviously a boost leak. Although hitting the fuel cut isn't necesarily a good things, you have a boost leak somewhere. Are you using a stock bpv/bov? the ar known to not hold high boost. also i would recommend a boost gauge because you could possible (though unlikely) be pushing more that 15.5 where the fuel cut normally is and that will most likely melt your pistons. In 3rd gear on i hit 15.3 psi and my stock "boost gauge" barely even gets into the red.
 

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Just some info on how my MBC+A is set to help any one trying to tune it. set at about 2.5 threads showing on the MBC and 2 turns out from closed on the A gives me a peak into the middle of red and then at about 4000 rpm it will settle to a quarter in red and hold. 2,3,4 gears are about the same indications, colder days the drop isnt as much or as soon in the rpm range,cheapo double pass ic, I guess.
 

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julianBC said:
like in the actual mbc+a? what kind of spring could i go get to replace it?

sorry, not the mbc, the turbo waistgate actuator, if the spring in there is a little weak the exhaust pressure can force open the waistgate so you loose boost
 

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an accurate boost gauge cost me 50 bucks (Autometer sport comp) and then installation can be tricky, but is easy... check out eric's site for details.
 
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