Air-to-air intercoolers
Most street and track cars use air-to-air intercoolers because they are simple and reliable. Air passing through the front of the car cools the charge air inside the intercooler core. Core size, fin design and ducting all matter.
Air-to-water intercoolers
Air-to-water setups use coolant to absorb heat from the charge air, then reject that heat through a separate heat exchanger. They can be excellent where packaging is tight or for drag setups, but they require pumps, tanks, plumbing and heat management.
Pressure drop vs cooling
A huge intercooler is not automatically better. The goal is efficient heat rejection with acceptable pressure drop and good airflow through the core. Poorly chosen cores or bad piping can slow response and make the turbo work harder.
Heat soak
Heat soak occurs when the intercooler system absorbs more heat than it can reject. On hot days, in traffic, or after repeated pulls, intake air temperatures can climb. Logging intake temperature is one of the easiest ways to understand whether the system is coping.