+1 on the UDP's, I loved them when I was N/A and definitely felt a difference when they were gone. They added 9 WHP to my car.

 

Exhaust won't really net you any HP.
Your car came with traction lock.
A good tuned CAI will cost you much more than $280. Expect about $500.
Underdrive pullies are a decent choice if you're staying N/A.
Your stock throttle body flows fine naturally aspirated.
If you want a custom tune, you'll spend about what your expecting to, possibly more.

With a good CAI and underdrive pullies and a proper tune, you could see as much as 300rwhp. The 4.10s will really help you off the line.

For the other guy: What's this business about centris being inferior to other types of superchargers? Having worked in the performance industry for several years, I can promise you that simply isn't true. (Coming from a twin-screw owner.)

 

I agree with you there. Average gain on an entry level supercharger is 30-35%, and 300hp flywheel, you'll now be about 400, compared to all those modifications which realistically won't put you much higher than 330 or 340hp flywheel. The other beauty of the supercharger is that when you have other supporting mods like fuel and cooling (intercooler/snow), is that you can change the pulley on the supercharger and gain even more, whereas those N/A mods will eventually top off, hitting a plateau until you get a power adder or other expensive mod like stroking, cams, or heads, all of which may still not get you to the horsepower level that the supercharger would have done on its own. If you're not installing them yourself, you'll also add some significant labor costs making your N/A build many times more expensive than that supercharger from the get-go.

I've also heard good things about Last Call Racing, give those guys a call and see what they think about your choices/situation.

Also, a centri isn't a bad blower design at all either, it's rather efficient and its power comes differently than the positive displacement blowers. Each have their unique benefits which depending on your application/desires/setup, and are still probably the best true bolt-on and bang-buck modification. Sure, they're expensive, but nothing can really gain you the power they can make, and when you compare an entry level supercharger against a big N/A build, they win every single time.