Grimmspeed Post MAF Hose Kit Black 2002-2007 WRX / 2004-2007 STI
Some OE parts look passable and others miss the mark. In the case of the factory post MAF hose, the quicker you can get it out of your bay, the better. Grimmspeed now has you covered with The GrimmSpeed Post MAF Hose Kit that not only looks better, but fixes the flaws of its OE counter part.
Grimmspeed hose construction improves flow with 2 main features:
The first is the smooth inner surface, removing the pockets from the OE corrugated folds. These folds are necessary for the factory rubber design for flexibility during installation and structural integrity. The Grimmspeed hose is made with reinforced silicone, which is flexible, but has strong structural properties that enable us to have a hose that is very easy to install without worrying about collapsing under vacuum.
The second feature is a tapered center portion, making sure the inner diameter matches the OEM air box and turbo inlet. A mis-matched diameter creates steps, which will interrupt the air flow trajectories and create small vortexes in the post-MAF hose. The Grimmspeed hose was designed specifically to prevent these issues: