I want to go with the BD twins but don't have enough money yet. But I need more air now, so I am going to buy a single. I am going to step up to mach 6's when I get the larger turbo. And eventually add a smarty. Right now with my Hx 35/14 cm housing on level 3 sub level 4 on the edge I can spin the tires in first and into second gear. I also see about 35 to 40 psi of boost. I want to be able to spool the new turbo like like the Hx35 spools. Is this possible? I like the power right off the line.