Upgraded Top-Mounted Intercooler

Grimmspeed TMIC compared to stockLike a lot of other stock parts, stock top-mounted intercooler (TMIC) works pretty well, but there's room for improvement. The core size could be bigger, and maybe more importantly, the flow through the core could be improved. In addition, late-model Subarus use plastic end tanks with the core crimped on. Over time the crimp joints can weaken and start to leak.

Aftermarket intercoolers feature large core sizes -- as big as can fit under the hood -- combined with bar-and-plate core construction that emphasizes maximum flow and minimum pressure drop across the core. The welded end tanks can never de-crimp.

We sell a variety of replacement TMIC units from different vendors, all of which are excellent choices. One intercooler that differs from the others is the Process West Verticooler for the 2008-2014 WRX. That intercooler is rotated 90 degrees from the stock horizontal layout, so the intercooler core stands up vertically. We can't say for sure if this design innovation is superior to the traditional layout, but we like the outside-the-box thinking.

Now that we're done with the lightest modifications, we can move on to mid-level mods.