Best cheap mods are: Making sure car is up on maintenace; i.e. stock type NGK spark plugs and wires ($50), correct timing (slight advance may help a little on the high end)(autozone rents for free), clean fuel filter ($12). Of course timing belt and water pump, and all other non-power adding necessities.On to the mods: Since you already have an intake. (make sure it is a good, CLEAN filter)Highflow catalytic converter (175 installed). Or gutted / race cat (free, but off road use only) Next, high flow exhaust custom @ muffler shop 2.25 is plenty big for non-turbo cars. ($120-200), of bolt on cat-back ($350-600)Then, header, small primaries and large collecter variety. These tend to extract the most power ($75-500).This is a good start. You may consider other things like clutch (250-450) Gripforce.com has 'em for cheap and they are good!Underdrive / lightened pullies and flywheels too.Hope it helps, KC