I am very interested in purchasing a Tial Bov but very unsure of what spring is best for my setup or if I should buy a lighter spring and add washers. My cheap amazon bov started leaking horribly and I figured I would upgrade. The car is a 2006 LS 2.2 with an aftermarket Turbo. My gauge reads a vacuum of -21/-22 inHG. This Chart off of Tial's website suggests a 12lbs spring and that is a lot of weight compared to some of the forums I have read. Most people are suggesting a 9lbs or 11lbs spring. Can anyone shed some light on the subject for me?