Grimmspeed Top Mount Intercooler Kit [Inc. Splitter] - Subaru 15-21 WRX - 090070Replace that undersized, plastic stock intercooler with a GrimmSpeed Top Mount Intercooler Kit, featuring cast aluminum end tanks, large bar and plate core and TIG welded construction. The factory FA20dit TMIC is well suited for stock applications, but when boost levels are increased, the higher post turbo air temps contribute to pre detonation (or 'knock') and loss in power. The GrimmSpeed intercooler is designed to keep charge temps consistent