How can I control the sharpness of corners using Subsurf? I'm trying to make these corners sharper after SubSurf. 




The solution that comes to my mind is adding edge loops to limit its space, but when I try to add edge loops they also affect the intake shape in front of the object in the same loop, deforming it in the way I don't want (I want sharper edges, but not round as I've done)



Any ideas besides boolean?
You can crease edges with Shift+e as well as inputing the Crease value in the n panel:





It is also possible to model the edge loops in such a way so they get narrower where you need sharper corners or edges. 

Using Subsurf is also not the only way to model things. It adds a lot of unnecessary geometry and it is always worth to consider if you could achieve similar forms with other modelling tools, for example, using bevels.