Simply the cheapest way to increase bottom end and midrange is with the Slater Skins high flow air box cover. Noticeable power improvement over the stock cover.
 
Integrated ventilation slots at the front of the cover and increased overall cover size have been implemented to address the restrictive OEM design.
 
Increased airbox size and ram airpower increase
With the increased air flow is a huge improvement over stock
Adds big HP and throttle response and allows your bike to rev further
Comes with washer clip to use with stock Dzus fastener
Plastic molded, lightweight, custom fit
Simple bolt-on
Made in the USA