WHAT IS IT? The Twin Air PowerFlow kit is a rigid, lightweight aluminum cage that is designed to replace the stock CRF backfire screen and filter system to improve performance by allowing more airflow.       

WHAT’S IT COST? $264.95.

CONTACT? or (800) 749-2890.  

WHAT STANDS OUT? Here’s a list of things that stand out with the Twin Air CRF450 PowerFlow kit.  

The stock Honda airbox design is quite unique.

(1) Stock power. In 2021, when Honda released its all-new model, the airbox was one of the most obvious changes to the new bike. The previous-generation bike required you to remove the seat to get to the air filter. The battery was also located inside of the airbox, reducing the amount of volume in the air box and making filter changes difficult; however, on the 2021–2023 Honda CRF450, the air filter is accessed by removing one 8mm bolt that holds the left-side number plate on. To remove the stock filter, you push up and unhook the aluminum bar holding the filter in place and pull it out. Although it is quick and easy to replace air filters with the stock system, it hinders the performance of the CRF. The backfire screen restricts airflow, and test riders said that the power delivery felt like a light switch. It was difficult to maintain consistent throttle through long, choppy ruts. Test riders also reported that the power would hit a flat spot just before the rev limiter. 

(2) Performance. By installing the Twin Air PowerFlow kit, we eliminated the backfire screen, allowing more air to flow into the intake system. With the bike sitting on the stand, the throttle response was noticeably improved. The engine had a free-revving feel that made test riders very excited to hit the track. Rolling onto the long start straight at Glen Helen Raceway, we noticed that the Honda CRF450R had a broader power delivery that pulled hard from the bottom to the top of the rpm range. The biggest difference was felt in the corners. Test riders commented that with the broader, smoother power delivery, they could get through ruts easier without having to rely on the clutch to keep the bike at the correct lean angle.


(3) Fitment. Installation of the Twin Air PowerFlow kit is simple, but it is time consuming because of the nine hooks on the filter-to-cage interface. Removing the airbox is not required if you lean the bike over on its right side. The stock backfire screen is held in with one set screw that will not be reused on the Twin Air PowerFlow kit. After removing the set screw and backfire screen, apply grease to the Twin Air base plate and slide it into place. Then install the threaded part of the back plate that will be used to hold the air filter cage in place. Take your time with this step, because you do not want to cross-thread or round off the heads of the two 2.5mm hex head bolts that hold the back plate in place. Be sure to apply Loctite to these bolts (Loctite provided with Twin Air PowerFlow kit). And last, install the air filter onto the new cage. Slide it into place, making sure the hooks are in place, and install the new set. Reinstall your side number plate, and you are ready to hit the track.  

WHAT’S THE SQUAWK? Installing the 2.5mm set screws into the backing plate can be difficult if you have large hands. Be sure to take your time on this step to avoid ruining your new Twin Air PowerFlow kit. When ordering replacement air filters, be sure to order the PowerFlow air filter, because the OEM air filter will not work with this system.   

MXA RATING: Improving performance while making a 450 easier to ride is always a plus for the MXA test riders. The Twin Air Powerflow kit did just that.


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