bypass valve vent to atmosphere
 

ok so today my car was acting up then i saw the hose that gose from the bypass valve to the intake cracked so i removed the hose and topped off the intake where the hose goes connected to. so far everything seems fine the car runs smoother than before. ok so i went for a drive and im gettin full 10.5 psi boost at 2600 rpm.

In short, the car/motor was designed/tuned for that by-pass to re-circ. Re-connect it or you run a very good risk of damaging your motor.

All Forced induction cars are designed to re-circ it is more efficient. Still everyone else run their cars (using word cars as any brand not just MINI) with venting to atmosphere with no real issues.

You will run to the same issue with any other mod, car was not designed to run 17% pulley or colder spark plugs ect ect.. to each their own

Um, AFAIK you CANNOT vent to atmosphere in our cars because the throttle body is before the supercharger SO if you vent to atmosphere then you'll also suck in air and the car will rev out of control.

Air entering engine AFTER throttle body = rev.

^I just (hopefully) fixed this issue. It should result in a p1237 code that may intermittently throw you into a limp mode.
The code is a secondary upstream MAP sensor low input.
Mine was caused (i think) by a dried out rubber hose between the bpv and supercharger intake duct (the 1.25" diameter piece) just clamped it down with some hose clamps and i haven't gotten a code again... yet.
It caused me to loose ~1 sec in a quarter mile, and the engine to loose lots of power in the 2500-3200 rpm range.

i bought another hose for the bypass valve and now its back to normal. when i had no hose connecting the bypass and the intake the car was running fine and no codes but i just went back to normal just to be safe.