Darth, if I were you I wouldthink you would want the larger housing with stg 2's in there. I pull a lot of steep hills so I want to move a lot of air at high rpm to keep egt's down. You give up a little on bottom for more on top with the bigger housing.I've got what is basically a 1.0 and I like it but I do have to keep an eye on egt's if I'm hammering on it for long. I'm gonna give the 1.15 a shot again soon. I'm told the small housing kills some mileage and my turbo runs five pounds of boost constantly.