Still how do I know the difference between BOV's, Like can I just go to a web site and pick out any BOV, if so then why should someone spend $300 for a name brand and not go on ebay buy one that looks the same on the outside for $30-80.00? Isn't there different springs, How does the BOV know when to let air out. My friend had a Turbonetics BOV and we mounted it on but when I hit the gas to hear how it sounded (car in park) the air came out the inlet side of turbo and I know thats not good, so there has to be some kind of set up when buying a BOV? ?