WHAT TO MODIFY WITH YOUR BUGDGET

The following contans my opinion not facts...i'm not responsable for anything!

Here's a guide of mods in a certain order which i recomend. Don't forget to check out my cars mods for the list of free mods...

First off, you must get an intake system, there are a few kits available most of which are expensive. I made mine with an akimoto intake for a prelude SH. It's butchered but it works. If I had to do it again, I would buy the RPM intake (pics are on Mike Dodd's site). The most important thing about the intake is that it must have a long pipe going as far down to the intake hole as possible. I dropped my 1/4 time by 1/10 of a sec by doing so(equivalent to 1 car length)!
If you pay for your own gas, you might want to get a PS91 ignition coil. This'll give you noticeable low end gain for 50$!! And it will pay for itself eventually due to the fuel economy gains. UPDATE: you'll need to upgrade the plug wires too because they can't handle the coil...so, adding wires (130$) makes this option less intersting but it'll still pay for itself. At least you now have an excuse to throw away those stock spaghetti wres :)...I would get the hedders first.
Now, you can get a set of hedders. I Recommend the RPM ones again cause of their low price and excellent performance gains. Typically this should drop you relatively stock mr2's 1/4 mile by 3 tenths of a second. It will also increase top end.

The next three mods on the list are up to you to decide:
Unfortunately you'll need to upgrade your exhaust pipe because it's restricting flow. (RPM hedder exits @ 2.5" versus 2" for the pipe) a good 2.5" pipe coupled with a lightweight suppertrap or dynomax is an effective way to decrease flow resistance. HK$ and Greddy aren't recomended due to their high prices and little gains. You can avoid this step and do it later on for it won't yeild a big HP gain.
Cams, If you can afford them get them! They will change the entire power curve of your engine. You'll be racing a different class of cars since you'll have plenty of top end to back your launch.
Port&Polish, again this is expensive however the incresses in power are somewhere between the cams and hedders...You can mill the head while you're at it to increase compression. Check out my other links for more info...