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Mbc In With Unexpected Results


HPTDoh

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After inspecting all my vacuum lines and re-securing the wastegate arm, I was still experiencing a boost leak. Today I finally got around to replacing the BCS with a MBC. I turned it all the way down and went for a spin. Awesome! It boosts slowly up to about 10 psi... problem solved, right?. Apparently not because when I start to turn it up, boost climbs super slowly and maxes out at about 5 psi. This starts at about a quarter turn up from the bottom.

Did I install it wrong? Seems pretty straightforward..

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did you try to turn it back down? what mbc is it..? if it's a cheap one, you may need to get a stiffer spring.. or try and stretch the spring.. i've heard it helps..

Yes, I left it all the way down just because I get the best performance out of it that way. It is a $20 ebay style one. Should I try stretching the spring before a new one? Where can you even get a stiffer spring?

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It is a $20 ebay style one.

Spending another $20-$40 for a decent one would have meant you wouldn't have had to make this post and you would be done troubleshooting. ;) I'd say splurge on a Hallman, but that's just me. Never had a single boost spike, nor any boost fade on my 940. It was rock solid for 4 years til I sold the car. Well worth the 70 I spent on it!

But if that's not an option...go to the hardware store and get some different springs. Spend a day mixing, matching, testing, and tuning. Hopefully that will work for you!

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Spending another $20-$40 for a decent one would have meant you wouldn't have had to make this post and you would be done troubleshooting. ;) I'd say splurge on a Hallman, but that's just me. Never had a single boost spike, nor any boost fade on my 940. It was rock solid for 4 years til I sold the car. Well worth the 70 I spent on it!

But if that's not an option...go to the hardware store and get some different springs. Spend a day mixing, matching, testing, and tuning. Hopefully that will work for you!

bleh.. I usually spring for the tried and true parts. But for this, I figured so many people use an ebay mbc, I couldn't go wrong.

How do I even go about dissembling it? Screw it towards the + til it falls apart?

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bleh.. I usually spring for the tried and true parts. But for this, I figured so many people use an ebay mbc, I couldn't go wrong.

How do I even go about dissembling it? Screw it towards the + til it falls apart?

just a thought..you might need some thread tape on that sucka

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Do you have a bleed? does the mbc have one or do you need one installed within the line? I with the homedepot mbc i made just adding a T in the line and then crimping the T part a good bit made all the difference in how the mbc worked..

I don't have a bleed. It did come with a T, though.. I don't really understand how this is supposed to work. Any pics? Does it go on the wastegate side or the turbo inlet side?

just a thought..you might need some thread tape on that sucka

I did intend to, but forgot. But it holds boost pretty well under the stock boost level, so I'm not sure that's the problem.

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