i just noticed this on tv today. they were doing an upgrade on the history channel to a pair of grand nationals. anyways, while watching i noticed that the inlet and the outlet to the intercoolers appear to be the same diameter. why? it would make more sense if the outlet was smaller.

i was thinking and to me it would make sense that if they were both the same size you would lost boost on the outgoing end.

 

If you make the outlet smaller than the inlet, you effectively bottleneck the system.

BTW, I would be pissed if I lost because the fuel pump went out. What a crappy way to go out.

 

i figured that since the cold air compresses from the hotter air, you would need the outlet to be smaller to maintain the same amount of boost as at the inlet.

 

The air doesn't really compress more, it just becomes more dense. Don't think of it in terms of boost, think of it as volume of air. Boost is a measure of intake restriction. You want to move the the largest volume of air through the system as possible, if you go to a smaller pipe, you reduce the amount of air you can move through the system. Think of trying to blow through a straw that's 1 cm in diameter vs blowing through a straw that's 1 in diameter. Which one will allow the most volume of air through it in the shortest amount of time. Clear as mud?

 

I would think you would want a bigger outlet for your intercooler. Depending on the size of the intercooler. If the volume of the intercooler is the same as the diameter of the pipe then you are fine, but I'm guessing it goes up and therefor slows the velocity of the air down. And when you put it back down to the size of the outlet you have to speed the air back up again. And usually you'd have to expand the pipe back up to the size of the TB which would slow it down again. So in theory you'd want the size of your intercooler outlet to be the same size as your TB.

I'm not sure how much this will actually help hp and efficieny of the system, but every little bit helps.