I am looking at a used crushed 1G bov and I was wondering if it would still work if I ran 14psi or 18. Also what exactly is crushed?

 

Here's a great explanation from Tuners.
http://www.dsmtuners.com/forums/showthread.php?t=220909
One more thing, if you crush a 1G bov, you can no longer run lower boost levels. Another thing, you crush the BOV because you want higher boost levels and crushing is permanent, not adjustable bro.

Replace the asterisks with D S M Tuner and your set.