Prelude vtec controller?

If your plugs are old you could look to upgrade them with wires to squeeze all the power you can out. That isn't too expensive. Also you could see if anyone makes under drive pulleys for your car. Also not too expensive. You could always look to upgrade suspension and brakes which many people overlook. Later down the line you could go with nitrous as a cheap way to go fast. Just remember when you get it, get a bottle heater, window switch, and Fuel pressure safety switch. But before you get into all that make sure you read up on it to make sure its for you. And remember weight reduction is free horsepower.