If you move the intake tube to the front you'll get a better responce from the engine thanks to the cold air. I fabbed up a whole box and put in a filter from a Ford SUV. Doesnt do alot for HP but does make a nice throaty sound when you pound the pedal. Better plugs will also make the engine kick a little harder. I put in Bosch platinum 4's and I could see a difference in idle RPM. Other than that you have to spend money .