for $150 i bought a highflow air filter, air intake piping, straight flow exhaust tip, and underdrive pulley. bought all off of eBay and have made 20 hp to the wheels. dyno tested.
http://videos.streetfire.net/search/...2401761127.htm. put down 181rwhp which is about 230-240 at the crank which is an increase from the 210 stock. my friend welded my exhaust on and i put the underdrive pulley and intake system on myself. might be over $150 with welding of exhaust unless you have a friend also. for the underdrive pulley look for ones for the 300zx (vg30de). as for the top speed, i personally have done 147 in my J30 on 985 going towards atlanta. didn have anyone in the car neither did i have a camera but it was a blast and a little bit scary cuz of how fast i was passing cars that were already doing 70-80. otherwise it was a smooth ride.