Post MAF host kit and air filter 2020 STI
Fitment of tube and air filter were perfect and not difficult to install. Nice products that offered a slight improvement in sound and performance. Worth the investment.
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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. We’ve now got you covered with The GrimmSpeed Post MAF Hose Kit that not only looks better, but fixes the flaws of its OE counter part.
Our 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:
Coupled with The GrimmSpeed DRY-CON Panel Air Filter, this will be the best way to maximize your factory intake system until it’s time to upgrade into a full GrimmSpeed Intake.
Note: If you’ve got a 2015-17 STI with the factory sound generator tube and want to delete that piece, you can either purchase the 15-17 post MAF hose and GrimmSpeed Sound Plug Delete, or opt for the 18+ STI hose to eliminate the sound tube provision altogether.
The first step in improving on an existing part is to find its shortcomings. The OEM rubber hose, designed with the corrugated folds, requires a straight section in the middle, which means sharper curves on both ends. This contributes to uneven air flow through the hose with high and low pressure spots. The GrimmSpeed hose design can support a minimal curve transition, maximizing air flow. The plot below shows the pressure through the length of the hose, the GrimmSpeed design resulting in a smoother transition from the air box into the turbo inlet:
The removal of the corrugated folds also adds a significant reduction in vorticity (a calculation used for flow disruption, with blue representing consistent flow and red more turbulent) between the two designs. Smoother flow will give us a more consistent air supply to the turbo:
The tapered center portion is also an important design choice for contributing to even flow through the hose. A plot comparison showing vorticity between a non-tapered version and Grimmspeed’s tapered hose shows an additional reduction in turbulence through the center of the hose where a majority of air flow will occur:
WARNING: Cancer and Reproductive Harm
Fitment of tube and air filter were perfect and not difficult to install. Nice products that offered a slight improvement in sound and performance. Worth the investment.
I received the items quickly and the fitment seems to be on point. I have the after MAF pipe on the stock air box and attached to a Mushimoto turbo inlet pipe everything fits snug and is a total upgrade to the stock pipe.
A very well constructed and manufactured air tube. The fit is spot on with a stock airbox. It worked perfectly to delete the original sound tube.
I ordered a post maf hose and a dry con air filter for my 2020 Sti. Very easy and fast to install, just need the right tools for it. Much better response. Turbo can be heard from inside the cabin. So far a fun experience.
I ordered a post maf hose and a dry con air filter for my 2020 sti. Installing parts was pretty easy and fast. Much better throttle response and a bit louder turbo heard from inside the cabin. So far I have been enjoying more than stock parts. No probelms seen since installation.
Ordered a post maf hose and a dry con air filter for my 2018 sti. Both products are great quality and fitment was spot on. Fast shipping too which is always great when ordering anything. Thank you Grimmspeed.
Love this new induction pipe - can keep the factory air box and MAF filter, got the dry con filter with it and the EJ20X in my 2008 WRX has come alive - top end power is great and turbo is on boost earlier - nice.
The post-MAF hose looks infinitely better than the OEM hose. Plus, smoother airflow delivery to the turbo is always a bonus.
Amazing product! Definitely woke my hatch up, perfect for someone who doesn’t want to tune !
My OEM filter was pretty dirty so I decided to order this kit. Filter fitment was perfect, very tight to where no air would escape through the sides. The post-MAF hose was easy to install and cleaned up the look. If you need to keep your warranty, this is a nice mod package that will give you a little more noise under boost.
Figment was perfect. Looks grate in the engine bay. Super fast shipment and not one not two three free stickers
Install was a breeze and coupled with the dry con air filter you can definitely tell a difference in performance.
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