Don intercoolers restrict the flow of air into the engine?
Yes. Any time there is an obstacle in the way of the air flowing into the engine (like an intercooler fin or louver), a pressure loss will result. Today’s intercoolers are very effective in minimizing this pressure loss so that the benefits obtained by cooling the discharge temperature normally outweigh the 1-2psi (approximate) loss in air pressure, which can be regained by increasing the boost pressure.
