I'm not so sure that you'd really see any meaningful difference in making the coldside bigger. The reason I say that is because most of us can pack more air into our engines than they can handle anyway. When that is the case, efficiency of design sort of loses some of it's luster. I did it just to even out the transition between all the components. MY IC, TB and Mass air are all 3" give or take a little bit. Didn't see the sense in making my pipe look like link sausages or pop beads. But, let's just say that I did it for what I'll call the Hair Spray effect. (That would be the drop in temperature you get whenever a compressed gas is going from a higher pressure zone to a lower one. In my case, from a 2.5" pipe into a 3" one.) Mostly insignificant in this case but hey!!! Ain't physics fun?

Ooops, I forgot most of you don't know what a spray can is that you don't have to pump with your finger....never mind. :roflmao: