I acknowledge that the product(s) being purchased () was/were designed and intended for closed course competition use only. The product(s) is/are neither designed nor intended for use on public roads or land and is against Federal and State regulations to do so. By proceeding with this purchase, I , agree to only use the product(s) for closed course competition.
Gain podium-worthy performance with the TST WORX Airbox. This entirely replaces your stock airbox with a race-tuned assembly made from premium materials, inside and out. Each kit is hand-assembled in our Florida facility and designed to improve airflow and engine performance, specifically in the top end of the RPM range, so you can achieve faster lap times and race day dominance.
Include the tune with your purchase to ensure your ECU is properly set up to handle the improved airflow. For the best results in tuning, we highly recommend seeking the help of a tech that has access to your bike and specializes in tuning race bikes.
We offer both non-ABS and ABS-compatible versions of our WORX Airbox. Use the dropdown to select the version you need for your specific Ninja 400.
Applications:
Kawasaki Ninja 400 | 2018, 2019, 2020, 2021, 2022, 2023
Including the tune? You are responsible for sending us a stock, untuned, undamaged, and unmodified Ninja 400 ECU. We will flash the ECU with your selected tune and send your ECU back to you. See the Tune Details tab for more information. The WORX Airbox will ship when the WORX tuned ECU ships.
The WORX Airbox comes pre-assembled, therefore we are not able to substitute items or customize the airbox or velocity stacks per order.
Need a replacement air filter? CLICK HERE.
This item is not eligible for discounts.
This product is part of our Worx Program!
Learn More!
CLOSED COURSE APPLICATIONS ONLY
Product Feature EpisodeInstallationAirbox Features
Velocity Stack Features
Air Filter Features
*Small tab located on the frame needs to be bent to provide proper clearance for installation. DescriptionOur quest for class domination has led our engineering team down a lot of paths, the latest being a complete redesign of the airbox assembly in an effort to create the best possible air delivery into the engine for optimized performance, especially where it's needed the most - the top end. What they developed after months of testing and design has not only executed that goal but done so in one of the most elegant and sophisticated ways possible. The new WORX Airbox is capable of increasing power by 5-10% in the upper RPM range between 9500 RPM and 12500 RPM, ensuring you have the power to separate yourself from the pack and drop your lap time. When paired with our specific WORX tune, or your own custom tune, the new airbox provides immediately noticeable improvements that will help you land your feet on the podium. The Toray carbon fiber intake construction mounts to a high-strength polymer back airbox structure, enclosing the new WORX Air Filter and V2 Velocity Stacks. The entire kit comes pre-assembled with the filter pre-oiled and ready for use. It drops in to replace the stock setup, removing with it the stock air filter and velocity stacks and replacing them with specifically designed components that take advantage of the improved airflow and further optimize the volumetric efficiency for better engine performance and faster lap times. This Ninja 400 Airbox is unlike anything else on the market. It not only delivers power performance gains but does so while being a perfect representation of the high-quality design and manufacturing standards we hold ourselves to here at TST Industries. You won't find this type of airbox anywhere else! Already purchase a WORX Ninja 400 Tune and want to upgrade? We'll provide a free tune reflash if you've already purchased a Stage I or Stage II tune from us before and can send in the same ECU. See the Tune Details tab for more information or CLICK HERE to get the free reflash. The WORX Airbox comes pre-assembled, therefore we are not able to substitute items or customize the airbox or velocity stacks per order. This item is not eligible for discounts. Tune Features
RequirementsIt is your responsibility to ship an undamaged and unmodified 2018-2023 Ninja 400 OEM ECU to our facility in Lake Helen, Florida for tuning. The ECU must be properly packed and free of any damage or contaminants to be tuned properly. Once the ECU is tuned, we'll ship your newly flashed ECU back to you for installation. Please note that if your "Check Engine" light is on previous to an ECU tune, the light may remain on after the reflash and will need to be cleared manually. If your ECU does not meet the requirements required to be flashed, we will not be able to perform the programming required to take full advantage of the other components in this bundle. It is your responsibility to confirm that your ECU is unmodified and undamaged before purchasing. If you have an ECU that has been previously flashed with a TST WORX tune and want to upgrade your Ninja 400 with this airbox, please CLICK HERE to add a free reflash tune to your cart.
*Airbox, Air Filter, and V2 Velocity Stacks come pre-assembled for ease of installation on your Kawasaki Ninja 400. Q: Do I have to do any modification to my bike or airbox?
A: There is a small tab that is attached to the frame that will need to be either bent or removed entirely, depending on your preference. On non-ABS models, this tab is not used for anything and is typically removed by most racers. No modification is required to the stock airbox as this is a complete replacement of the airbox assembly. Q: Can I use a stock air filter or other aftermarket air filters with this airbox? A: The air filter that is included with this airbox has been specifically designed to fit within the reshaped design. The stock air filter or any other aftermarket filter that has been designed for the stock airbox will not fit. Q: How often do I need to clean or replace the air filter? A: We recommend checking the air filter for visible debris after each race weekend. You can clean and wash the open cell foam filter and re-oil it with your preferred filter oil. If you decide you need a replacement filter, click HERE to order a new one. Q: If I already have a WORX Tune on my Ninja 400 ECU, can I get the Stage 3 Tune at a discount? A: Absolutely! We actually offer a free reflash of any previously tuned ECU right HERE. Just pay the $15 shipping and input the original WORX Tune order number and we'll get your ECU reflashed so you can take full advantage of the improved airflow. Q: How long will it take for me to receive this once I order it? A: Our handling time is 1-2 business days, and the shipping time varies based on the shipping method selected. To learn more about shipping times, please see the articles in our Terms & Conditions regarding domestic and international shipping here. Q: I'm located outside of the United States. Will I have to pay duties on this item? A: Some countries charge additional fees when a package is imported and delivered to the recipient. We have no way of knowing or estimating what these fees will be. It is the buyer's responsibility to cover these additional costs. Q: What is your return and warranty policy? A: Please read over our policies thoroughly on our terms and conditions page BEFORE making your purchase. TST Industries Terms and Conditions |
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