mbc cant turn down boost

[pur97tsifwd]

ok i have a turboxs mbc and i cant seem to turn down the boost i got a 3inch turbo back exhaust with dump and i am hiting 20psi and i dont want to blow the motor but i cant turn down the boost with the mbc i dont know if i have it hooked up wrong or what?

 

[crunchymilk]

a boost controller will not let you lower the boost more than stock. That being said, 20psi is obviously much higher than stock, is the screw all the way out on the mbc? If it is, then just unhook the mbc and run the line straight to the wastegate.

 

[MrBoxx]

Here are a few Paint pics to help you out on how to hook up a TurboXS MBC. Once you've confirmed that you hooked it up correctly, or fixed it so it is correct, we can go from there.

Pressure source from Intercooler Pipe/Compressor Outlet:

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Wastegate Actuator:

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I know this pic is a little busy, but it shows generally how a TurboXS will go. Even if you have the Dual Stage or the base model (this is the High Performance model) it should be the same.

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Try hooking it up this way, make a run, and see what happens.

 

[pur97tsifwd]

my screw is all the way in i got the blue line on the wastegate and the brass side on the intake i cant find a pressure line on the turbo

 

[MrBoxx]

The pressure side needs to have a pressure signal from after the turbo, preferably as close to the turbo compressor outlet as possible, and NOT from the BOV line. If you don't have a nipple on the turbo or lower intercooler pipe, you'll have to make one. Drill a hole in the LICP and tap the hole so a 1/8" NPT nipple fitting will screw in. File off any excess fitting on the inside of the LICP (so put it close to the pipe opening so you can get at it) and use the nipple as a boost source.

 

[oldman]

If the problem persists after verification of correct MBC installation, do a search on "boost creep".

 

[crunchymilk]

Wait your pressure source is coming from the intake? That's wrong

It needs to be tapped into the BOV line for now. When you can, get a 1/8 fitting tapped into an intercooler pipe and run it there.

 

[MrBoxx]

On a TurboXS MBC, turning the screw counterclockwise (out) will raise boost, not lower it.

 

[pur97tsifwd]

can i just hook up the stock controller and be safe

 

[oldman]

2g's done have a pressure source on any intercooler piping. You need to turn the screw all the way out.

He has a TurboXS bleeder mbc, not only the fittings are reversed, comparing to your everyday ball/spring type, the adjustment is also reversed, "in" = less air bled off = lower boost setting.