Ask the Editors: Air Filter Power
Is there power to be gained here? Yes.
Believe it or not, it’s true. That’s probably the upper echelon of the type of horsepower gains that can be expected but there is very solid science behind gaining power by ditching the stock air filter for something that flows more O2.
The sad reality about our ATVs, yes even the ones designed to race/ for performance is that the government has extremely tight regulations concerning the state of tune they must be in to be sold to the public.
The manufacturers have to literally de-tune them at the factory level to meet sound and emissions regulations. One of the ways they achieve this (aside from mellow fuel mapping, and massive exhaust systems) is by restricting the amount of air that reaches the engine via the intake.
A few years back we tested the then-new Polaris Outlaw 450MXR and found it was popping wildly upon deceleration all around the motocross track. We opened up the air box and not only did it cure the popping, the machine gained power all across the boards. This was one of those situations where were it ours to keep, wouldn’t have only went with a freer flowing air filter but likely an aftermarket intake system as well.
After market air filters are designed to be less restrictive than stock while still performing the crucial task of keeping airborne crud from reaching our engine’s internals. There is almost always free horsepower to be gained in this department.
