boosty: you need more camber or you gotta pull the hell out of your fenders (which will leave them stupid looking if you ever go back to a normal sized wheel/tire).
baker: usually when i see people go to smaller widths they stick with the same aspect ratio. any reason why you chose 225/40 over 225/45? (for instance, the 'proper' tire on a 18" wheel for my subaru is a 245/40/18 and people just downsize the width and run 215/40/18 on their wheels instead. from there they factor in camber and rolling/pulling fenders for clearance.)