I guess when NASCAR or any other type of racing requires a restrictor plate (that is typically only 1/8" thick) to cap power, they simply do it to "LOOK" like they are holding back power? PLEASE, if someone told you that they are nuts or a test they might have been done had serious issues. An example would be testing a car that might having been running seriously lean to where power was killed from a too lean condition, then installed a larger throttle body to let even more air in would not make more power. The farther you get from stock the more a custom tune is needed to bring it all together. A properly tuned car will make more power with the system able to flow more air if the proper fuel is also added. A person just bolting on parts and not thinking about or looking at the tune can easily come to poor conclusions.
