Superchargers are junk for engines that small. You need a turbo.While a supercharger makes a more consistent intake charge because it doesn't have to spool up, it is driven by a belt that attatches to the crank pulley. As it is giving you power from the charged intake air, it takes it away by adding resistance at the crankshaft.A turbo is free horsepower - since it works off of exhaust flow it takes away no power and can be set up to give much more of a gain than a supercharger can.But you said you didn't want to force feed the engine, so here are some tips to making more power with a naturally aspirated engine. You have more airflow with the CAI and exhaust, but that airflow is almost useless to you, and I'm going to tell you why.The heads on your car were designed to flow as much air in and out as the stock intake and exhaust could allow. All of the extra air your providing basically comes to a bottleneck at the heads. However, a little of the extra will get in, but it will also have trouble getting out through the exhaust.What you need to do is remove the heads and take them to a shop that does machine work. Get them ported and polished. While you have the heads off you'll want to change the cam(s) to longer duration ones, because you'll run into the same problem as before if your valves only open up long enough to let the stock amount of intake in. For more accurate timing you may want to ditch the timing chain in exchange for a set of timing gears.After that you'll want to upgrade your fuel and ignition systems. Get a better throttle body, fuel pump, fuel rails and better injectors. For the ignition you'll need a better coil, better wires and you'll want to change the plugs.Now's the time to tune your computer (if you have the cash, upgrade to the new AEM ECU first). If you don't do all of this at once, you'll want to take the car to a dyno shop for a tune each time you add a few mods. If you do all of this stuff at once then just have it tuned when you're done.You're looking at 3-400bhp right there, with no boost lag and no power robbing supercharger.Oh yeah, someone above mentioned nitrous. If you decide to put the car on a bottle then you'll probably want to replace the pistons and rods with forged units. That's really a good idea even if you don't do the nitrous, it will make the engine last much longer. 400 ponies put a lot of stress on the insides, especially at high RPMs.If you can't afford all of this stuff, which is probably the case, I recommend the AEM ECU. It would be the single most advantageous modification I've listed. If you can afford it, the port job would do wonders when coupled with the new ECU.