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DHM Stock Airbox Mod Kit for Honda Grom (does not fit Monkey)

Add Koso Tube
Add Koso Hurricane Filter

The DH Motoring Stock Airbox Mod Kit will allow you to maintain your stock airbox but with the flow of an aftermarket intake! This is perfect for sleeper builds or for offroad riders that want the protection of a sealed box instead of an open filter. Using a KOSO intake tube that was originally designed for their 34mm throttle body, we've developed a billet eccentric adapter that allows the tube to be used on the stock throttle body.  

You can purchase the kit in different configurations if you already own certain parts:

  • Adapter Only (If you already own a Koso tube)
  • Adapter and Tube (If you plan on keeping your stock filter or already own drop in filter)
  • Adapter and Filter (If you already have a Koso tube but need a Koso filter)
  • Adapter, Tube, and Filter (the entire kit if your airbox is completely stock)

Key Features:

  • 6061 machined aluminum adapter
  • Stainless steel set screw for corrosion resistance
  • OEM-Styled larger inlet tube 
  • Optional Koso Hurricane high flow air filter for the stock airbox
  • Increased top speed 
  • Increase throttle response 
  • Increased HP and Torque 
  • Retains OEM Intake temp sensor placement
  • Retains stock airbox for increased protection against the elements

If you don't already have our flash, this setup along with your aftermarket exhaust pairs extremely well with our Stage 1 Reflash or Cam Package!



Customer Reviews

Based on 31 reviews
Michael Boschert
Great Mod, but a little lacking on install details

With this Mod and the ECU Flash, my 2020 Grom definitely woke up across the entire RPM range. Easily hitting 60 MPH now and on those long pesky hills, a downshift to 3rd keeps the power pulling. Can easily keep up on 45MPH roads in East TN which means traffic is doing 50-55MPH. Not only does the power increase but the motor is running safely at 7K RPM and higher. Unless your are a geometry wiz, the easiest way to install the airbox mod after making the 40.5mm (4.05cm) hole in the airbox, is to first install the KOSO tube to the Airbox, then the adapter into the tube, then reinstall the airbox on the bike, last the KOSO Tube with adapter ring onto the Throttle Body. The DHM Throttle Body adapter sits on the outside of the Throttle Body, so there is no way for the set screw to come out of the piece and into the throttle body. Honestly not even sure why it is included. It is a super tight fit on the throttle body and in the KOSO tube. Again it only fits one way in the Koso Tube and once it is clamped its not going anywhere. All of this only fits one way, so taking the throttle body off won't help when trying to reinstall. I went with this over the MNNTHBX air intake kit as I prefer a stock look and not sure how much off-road I will be doing, but this setup is definitely better if dust/dirt/water is concerned. However, the MNNTHBX mod would be way quicker. For me I am happy and glad I went with this setup, its also cheaper. I used the thicker foam filter that was already installed in the Hurricane filter. Suggestions for DHM: give a bit more info with the kit, like does it even matter which included foam air filter to run with the ECU flash? Add an Allen wrench for the set screw or at least tell what size it is in some included documentation, on the website, etc. I have precision set none fit. I feel like since this is DHM's name branded kit, I shouldn't need to go to away from their site to find someone else's video on install guide or tips, of which none I found answered these two questions I had. I'm sure I could have reached out, but didn't know I had these questions until after hours, so I was in it to finish it at that point.

Paul Stover
DHM Stock Airbox Mod Kit for Honda Grom

Works as expected and was an easy install.

Denis Stubblefield

DHM Stock Airbox Mod Kit for Honda Grom (does not fit Monkey)

Suck, squeeze, bang, blow! More suck!

Put the stock airbox mod kit on a ported and polished standard TB that’s been bored out to 28mm. Well crafted, fits nicely, noticeable performance benefits. Received in the UK within a couple of days of postage. Makes me happy.

stephane piasco
can be perfect .....not completelly.

motorcycle much more pleasant, much more flexible, reflash ECU and intake tube kozo 175 dollars, 150 dollars of shipments and taxes (france), as we say at home, "it hurts the ass".
overall satisfied with the transaction.