Should i use a higher xbox 360 power supply?

i modded my jasper 150w xbox 360. I added more fans,leds,etc. now i notice the back fans are not blowing as much air as they did before. I want to continue adding new mods but i dont know if i should upgrade my 150w power supply to a 203w power supply. Would it even help the problem if i did upgrade? Or will it still only use the 150w?