Airflow. Powerful motors will sometimes run well enough at speed but overheat at idle. For example, after receiving an upgrade like a camshaft with more radica

Airflow. Powerful motors will sometimes run well enough at speed but overheat at idle. For example, after receiving an upgrade like a camshaft with more radical timings. One key point: you can increase the size of a radiator or oil cooler but that helps a lot more when the vehicle is actually moving.