Im thinking of making a custom 80 mm to 40 mm fan adapter so that i can cool my graphics card more... and i was wondering in order to keep the backpressure low.. will i need to make a little hose or small output in the adapter so i dont have air blowing out the intake side of the 80 mm?

Just wondering, i've heard the blow off valve idea before, just wondering if itd be necessary


Thanks...