Any Ideas For Cheap HP For a 98 Cobra?

[98mustangcobra]

I have a 1998 Mustang Cobra and i am looking for more things to do that will give me Max Hp Gain for the least amount of money. I already have air intake, throddle body spacer, under drive pulleys, programed, heads ported and pollished, racing pistons rods and Crank, Cams, Headers, Offroad X-pipe, Boost Cooler, Hp Chip,and injectors. Im looking for more ideas that are on the cheaper side with a good HP gain.

It would be great to hear some ideas.

Thanks and have a great day.

I not looking for Turbo's or superchargers. ( NO NOS i dont like it)