I made my own airfilter today by using air filter foam from ace hardware. Just use the plastic frame from the old filter, cut out the paper and cut the foam (spray it with a light wt oil) fasten the foam to the plastic. I used wire coat hangars for this. Just cut the wire where it will jam in the plastic. The foam can be purchased just about anywhere that furnace filters are sold or lawnmower parts are sold. If the filter material is for a furnace it has to be oiled as the material is slightly more porus than actual air filter material. While youre in that airbox remove the snorkel to increase the airflow. For extremists unplug the vaccum hose that goes to the intake selonoid. This doubles the max airflow. Needless to say balls to the wall on top end and also increases performance on bottom as well. One more that i didnt do it to place about 4 washers under each front tank bolt to allow more air to reach the airbox less restricted. Great, cheap and probably the easiest performance boost out there. Have fun
