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.
Replaces the entire stock airbox with a race-developed design
2.5 lbs lighter than the stock setup
Bolt-on component – no modification required*
Provides 8% increase to peak power compared to stock airbox
Provides 5-10% increase in the upper range (9500 – 12500 RPM) compared to stock airbox
Carbon fiber and high-strength polymer construction
Toray Carbon Fiber Prepreg features a high gloss clear coat for UV protection
Includes WORX V2 Velocity Stacks for optimized top end performance
Includes specific WORX developed pre-oiled foam air filter
Comes pre-assembled and ready for installation
Non-ABS and ABS-Compatible versions available
Norton Motorsports recommends our Velocity Stacks over the TST Velocity Stacks, as well as our own tune:
Air Filter Features
Developed to optimize airflow within WORX Airbox and provide reliable engine protection
Specifically designed to fit within the WORX Airbox
Pre-oiled and ready for use
Open-cell foam filter medium
Washable and able to be rejuvenated with your preferred oil
Recommended to be inspected after each race weekend
Replacements are readily available if needed
*Small tab located on the frame needs to be bent to provide proper clearance for installation.
Our 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!