actually Mr. Daze of Zero u are correct…with non-intercooled applications turbo placement also has a factor…cause lets face it…on a STS Rear-Mount FBod kit the tubo is miles from the throttle plate also reducing the effect the charged air might have on the turbo…Y didnt GM put them on their cars…well they are GM and in the mid 80s early 90s they could prolyl careless…does not having a BOV or ReCirc valve mean ur gonna kill ur car or turbo…NO it just aids in extending the life