If you turn up the boost too high yes i imagine you could potentially blow up your engine. It depends on what condition it is in, adding 40-50hp via boost will very quickly show you things that need looked at. Prior to doing anything i'd carry out a stage 0 and make sure it is running in tip top condition. If you don't things will go wrong. Since turning up the boost on mine i've replaced exhaust, head gasket, all belts, water pump & spark plugs.

The stock Volvo boost gauge doesn't show pressure readings and as such you can't rely on it when using an mbc. The low pressure turbo (LPT) engine usually runs at 4psi, high pressure turbo at 7-8psi. There's also the Turbo + fitted cars which run about 14 for 30 seconds or so at wide open throttle. Install a proper boost gauge into the car, it's rather easy to do. This will then be calibrated and you can see how much boost the car is running, 10-12 is considered OK. Mine is running at 10.

The mbc fits to the hose on the turbo between pressure side & wastegate as shown by TIPSP on the first page of the thread. Stick your head into engine bay and look at the front of the turbo housing, the wastegate should be clearly seen - look for the hose connecting to it. Be sure you get everything else in check prior to installing it tho...otherwise you might end up spending a lot of money repairing things...

 

i hooked up my gauge and when idling its at 20. When i slowly start going it reads 5psi and if i gun it it goes to 9psi so when i install my mbc how do i read if i went to high do i have to adjust it and keep taking it for a drive to see how much it went up and should i drive it slow or floor it when i adjust

 

you adjust the MBC so @ WOT you will hit the desired PSI.