GrimmSpeed Post MAF Hose Kit – 15-21 WRX

( 3 Reviews )
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Less turbulent air means better flow. Increased flow equals more power!

Our post MAF hose construction improves on OE with 2 main features:  

First is the smooth inner surface, removing the pockets from the OE structural corrugated folds. The GrimmSpeed Post MAF Hoses are comprised of 4-ply silicone and unlike our competitor's offerings, are reinforced with an internal stainless steel wire running the length of each piece. This makes our hoses sufficiently flexible and also allows them to retain strong structural properties for a design that maximizes flow, is very easy to install and won't collapse under vacuum.  

The second feature are tapered end portions, 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 hoses. Our variants are designed specifically to prevent these issues.


The first step in improving on an existing part is to find its shortcomings. The OEM rubber hoses require sharper angels and corrugated structural folds as part of their design. This contributes to uneven airflow through the hose with high and low pressure spots. The GrimmSpeed Hose design supports a minimal curve transition and is perfectly smooth inside, resulting in more consistent airflow to the turbo:



The tapered portion is also an important design choice for contributing to even flow through the hose. A plot comparison showing vorticity (a calculation used for flow disruption) between a non-tapered version and GrimmSpeed’s Tapered Hose shows an additional reduction in turbulence:



  • 4-Ply Stainless Steel-Reinforced Silicone - Extremely durable, yet flexible; available in red or black 
  • OEM Fitment - Easy install, no modification required 
  • Seamless Flow - CAD optimized design  
  • High Quality Breeze Hose Clamps - Included in every kit
  • No Tuning Required - Even when coupled with GrimmSpeed DRY-CON Panel Air Filter for maximum performance
  • GrimmSpeed Logo to Represent your Favorite Brand!


  • 15-21 Subaru WRX 

Written Install Guide

3 Reviews

Carlos A 28th Oct 2021

Good results!

Easy mod that just makes sense to get if you're not trying to shell out intake money and trying to stay stock as possible for warranty stuff. Look clean. Easy to install. Sounds great with my Nameless 4inch mufflers.

Bo 28th Oct 2021


To the comment when I said I have a custom exhaust I meant to say I have a stock exhaust!

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