Kawasaki KFX 450R Air Box Intake $179.95

All CFM Performance items are proudly 100% made in the USA.

Guaranteed to make more power than any other intake, air box, or air box eliminator or your money back!!!

New aluminum air box for the Kawasaki KFX450R. Will fit any year. It replaces both the box and restrictive intake tube. Don't waste your time with anything else. We have tested them all, both on the dyno and on the track, and this system makes more horsepower and torque across the entire RPM range than anything else.

The plastic cone shaped intake works better than stock, but has 1/2 the intake volume of this box. Because they use a conical shape, they are limited to a cone that will physically fit in the available area. Our intake has twice the volume because we take advantage of every last bit of the available space. We are not limited to a cone shape. You pay a small penalty for having sharp edges inside the intake, but it is more than made up for because we have twice the volume. On an otherwise stock machine a 6HP gain is common. We have seen up to 10HP increase on highly modified ATV's.

We do not have any graphs available. We use the dyno as a tool to help develop the intake, but the dyno graph only tells part of the story. We use real world drag racing and lap times more than dyno charts.


Aluminum intake flanges only use a 3 1/2" to 4" filter and require that you continue to use your stock intake tube. Air box eliminators make a little more power because they replace the restrictive intake tube, but they use a tiny 2 1/2" filter. This air box uses a HUGE 4 1/2" filter. The largest one available for any ATV. The worst part about an air box eliminator is that you stand a pretty good chance of destroying your expensive engine the first time you get into dirt or water.

The high volume/ high velocity plenum creates a vacuum that exponentially increases as your engine RPM increases. The result is more horsepower and torque than running with no intake or filter at all !!! 

The air box is made from 5052 series aluminum. All fittings are 6061. All hardware is stainless steel. Come with a silicone adaptor, hose clamps, and everthing that you need to install it.

Installation is very easy. Only takes about 30 minutes with basic hand tools. You will need to remove the rear fenders, stock air box and intake. The stock air box is mounted to the inside of the subframe with 4 bolts. These holes are drilled 90% of the way through. You will need to drill them the rest of the way.

Does not come with a filter. Uses UNI filter part number NU-4140ST, $40 and K&N RU-3480, $80.

You will find installation easy once you get started. We will be happy to answer any questions you may have. To install: Remove the stock box, intake tube and mounting brackets. Leave the short round straight piece that is attached directly to the throttle body in place. Drill the 4 holes the rest of the way through the subframe. The small machined aluminum support ring that came with your new air box goes inside the original short round straight piece that you left on the throttle body. The rubber adaptor that came with the box will go over the short round straight piece you left attached to the throttle body. Mount the air box to the subframe. Install the sensor in the front of the new air box.

Your stock air box has the crank case breather hose attached to it. This air box allows for so much air flow that the crank case breather hose can not be attached to the air box because it can actually suck oil out of your crank case and into the air box. We leave the breather hose open and tie it to the frame in the highest location it will reach. We have run our ATV's with an open breather hose for many years, in all riding conditions with no problems. The crank case maintains positive pressure on the hose making it virtually impossible for anything to get in. The open crank case breather hose has been standard on many ATV's for years. If you would like more protection, you can add a crank case breather filter to the hose.


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Kawasaki KFX450R KFX450 KFX 450R Air Box $119.95

All CFM Performance products are proudly MADE IN USA.

New aluminum air box with lid for the Kawasaki KFX450R.

Will fit any year, including special edition models.

On an otherwise stock machine a 3HP gain is common. We have seen up to 5HP increase on highly modified ATV's.

The stock air box uses a small 3 1/2" I.D. filter that isn't held in place very well. This air box uses a HUGE 4 1/2" filter. The largest one available for any ATV. It is securely clamped in place to make sure you have a perfect seal.

The air box is made from 5052 series aluminum. All fittings are 6061. All hardware is stainless steel. Comes with everything you need to install it.

Installation is very easy. Only takes about 30 minutes with basic hand tools. You will need to remove the rear fenders, stock air box and intake. The stock air box is mounted to the inside of the subframe with 4 bolts. These holes are drilled 90% of the way through. You will need to drill them the rest of the way.

Does not come with a filter.  Uses UNI filter part number NU-4140ST, $40 and K&N filter part number RU-3480, $80.