It depends on what kind of car you have first of all. An SE w/ intake and exhaust mods will gain more than an SVT most likely b/c of the SE's more restrictive airbox and exhaust. Do a search for 'intake' or 'exhaust' on the forums. Many/MOST ppl recommend the KKM for the intake and seems to be good for around 5 HP. For exhaust, non-SVTs remove their resonator and stick on a higher-flowing muffler. If money permits, you can do a Y-pipe, headers, etc. Go to the contour.org main page and on the left side there is a MOD link. Click it and it'll answer most of your questions. Also, using the search feature in the upper right corner of the forums will answer more than anything else.
