honestly theres alot of things you can do but most will only get you a nominal gain. for instance you could put on an intake, replace header and exhaust, high flow cat, cam gear, under drive pully kit, head swap for an ex head, swap intake manifolds from an ex, internal work, turbo, nitros, jrsc, whatever. As stated the dx motor isnt realy the best platform to be running off of. Obviously you can increase the HP but depending on what your intneded HP goal is you might want to consider a swap to help you along. but since it seems you are on a very low budget Ill be honest. You can get HP with out giving up a little but (alot) of green. BTW in your current situation if you have 5 people in your car passing isnt something you should be trying to do heh.