replied to the thread Intercooler Comparison (BMW Stock vs. Wagner EVO1 vs. HPF vs. Mosselman)
" Of course density matters. That's why NA cars make more power in the cold. That's why turbos make more power in the cold (more efficient turbos). But it has absolutely nothing to do with what happens after the turbo. The thing is... velocity of the air is just as important to get the air in, as the density of that air. If you have air that's less dense but it's going much faster, you'll make the same power as a car sucking denser air slower. If velocity wasn't important, velocity stacks wouldn't exist, intake manifolds and heads would be designed different, etc. In your turbo system, when you cool the air yes sure it gets more dense, but it's also now moving slower. The end result is the motor takes in less of the dense air, making it back up more and have higher pressure at a slower speed. So thus your pressure drop on the intercooler isn't related at all to the cooling of the charge/density, only to the resistance to flow.
I concede, I cannot explain this one well enough. Sorry guys. "
Yesterday, 11:39 PM