GrimmSpeed 02-07 WRX Top Mount Intercooler - Manual (Page 7)

Figure 12: Assemble y-pipe
10. At this point, you can make sure that the straight silicone coupler is centered
between the two y-pipe pieces before tightening the t-bolt clamps. Orient the
t-bolt clamps as shown below to ensure proper clearance in the engine bay.
Make sure that the t-bolt is sealing behind the bead on the cast parts, not on
the bead.
Install 12mm bolts