What is this valve??

[ftomas]

Hi
I have a frontera with 4jb1TC.
Front mounted intercooler.

My motor has similarities to the 4jb1 mounted on the trooper...
here is one vauxall (or opel) frontera 2.8 in europe


here is mine


and here is the trooper

I take this photo from a post here...



As you can see the frontera 2.8 doesn't have the valve i indicate in the third photo, and mine has....
On the frontera the tube is connected directly from the breather to the the tube before the turbo (tube from airbox to turbo) and on mine that tube has a derivation to that valve.
I take it off and i saw a valve with a spring, i think when pressure build in the intake that valve opens and some pressure goes out to the breather.

So my questions are:
whats the propose of that valve?
Its for all 4jb1? with turbo and intercooler?
Is there any danger in blanking it?
is there any benefit of blanking it?

[pig75]

It's a over boost valve. If the turbo ís making too much boost it will dump air back into the inlet side of the turbo

[ftomas]

It's a over boost valve. If the turbo ís making too much boost it will dump air back into the inlet side of the turbo

huumm ok, so maybe with the years the spring has lost the strength and can open too soon...
The forntera with intercooler and turbo doesn't have this valve, maybe i can take it off?

thanks