It's all to do with what eightyeightmph was describing. When stationary with the engine fully upto temp, with an induction kit, the air being sucked into the inlet is coming directly from the hot engine bay. The hotter air gets, the less dense it becomes. The less dense air is, the less oxygen it contains. The less oxygen it contains, the more it inhibits the combustiopn process from being as efficient as it can. So you need cold air rather than more air to prevent heat soak, which feels like the engine is being kind of bogged down
