Guy on clubrsx dyno'd with the chambered and it performed no better than the stock airbox.im thinkin of an intake......
http://passwordjdm.com/PasswordJDM-Carbon-Kevlar-PowerChamber-Intake-DC5-EP3-P1910C379.aspx
or
http://cgi.ebay.com/ebaymotors/INJEN-COLD-AIR-INTAKE-02-06-ACURA-RSX-TYPE-S-SP1477_W0QQcmdZViewItemQQcategoryZ38634QQihZ010QQitemZ200229088782QQrdZ1QQsspagenameZWDVW#ebayphotohosting
or just a k&n drop in filter
You should buy this:
http://www.clubrsx.com/cr/FUJ-CS-1005-p-ICATS.html
PS> You should also get the mugen lip (or a knockoff) they look awesome on the 05-06's.