A intake, spark plugs, cam gears, discap, they all arent really power modders. Intakes on 4 cylinder engines are about as worthless as changing your airfilter to a clean one, there are no real gains to be had. Unfortunately the only way to make power on these cars is with mods that require money be invested, every single power added requires some sort of tuning, and that costs money.
B18C's are hardly glorified B16's, the B16 is a damn near backwards motor with a 81x77 rod/stroke, where B18C's actually make power the B16 does not, anything short of putting that thing in a gokart tube frame or a shifter kart it is a pointless engine to mod, most of them dont make power till after 7000rpm and what power then do make below that is typically under 100hp. I see people bragging all the time on HT, 500whp B16 daily driven, yeh of course its daily driven, it makes 37whp @ 5500 rpm. I wouldnt even want to daily drive that because it would be too slow for me driving around town.